Talk:Thiamine

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Diseases

Can someone please clear up

" Well-known syndromes caused by lack of thiamine due to malnutrition or a diet high in thiaminase-rich foods include Wernicke-Korsakoff syndrome and beriberi, diseases also common in chronic abusers of alcohol.

"

I don't understand these two sentences. Does it mean that the diseases occur in Thiaminase deficient diets *AND* in chronic abusers of alcohol, or *JUST LIKE, AS IN* ...

bah!

It might be clearer if you recall that compounds ending in "ase" are enzymes which lyse or divide the compound listed before it. Think about penicillin and penicillinase (an enzyme made by bacteria) which prevents the PCN from working. If the diet has a lot of -ase it will break down the compound ( here thiamine) causing deficiency. Alcoholics are generally malnourished because they would rather drink than eat well.Hope this helps. Hoot 21:02, 7 February 2006 (UTC)

Well. Perhaps Umetaro Suzuki takes the gold for discovering B1. Or perhaps it was Casimir Funk who did it. We might even credit Christiaan Eijkman. However, it seems unlikely to credit Mr. Suzuki because his discoveries would have been well-known in Japan, and the officers running the POW camps would have augmented the prisoners' diets and saved a vast number of lives. Only a small amount of B1 is required to save a person. Obviously the Japanese Imperial forces did not know this fact, which reasonable persons should have known under similar circumstances, or they would have moved swiftly to prevent the slaughter, so I can only conclude that they did not know. If I were to say that they knew of their famous countryman's discovery and did not use it so save lives, that would be slandering Japanese officers. You can have Mr. Suzuki, or the warcamp tenders, but I do not grant you both. Choose carefuly, grasshopper. regford 20:10, 4 March 2006 (UTC)

The Suzuki commentary above presupposes that if: something is "known" scientifically (published and/or made known to the government), then: the government or surrogates (army) will not only "know" this, but also that public policy and public practice standards have been informed accordingly and all agents act accordingly. Seems we need some other type of argument re: Suzuki et al above. This "the Japanese officers could not have known," argument vs. Suzuki seems lacking to me at least. 72.63.48.114 (talk) 21:49, 19 October 2008 (UTC)gale

Synonym for thiamine

Someone should add to the article that 'aneurin' is another name for thiamine. 193.77.101.102 17:03, 1 September 2006 (UTC)

It looks to me like Biotest is advertising more then it is educating.

They cite no studies to demonstrate that thiamine di(2-methylpropionate) disulfide is more easily absorbed, also absorbed doesn't mean it's biologically active. I googled the words "biologically active" thiamine, and it was "Thiamine pyrophosphate" which kept appering as the most active form of thiamine.

I think biotest is using Wiki to peddle their product, what say you?

Nutrition science news?

It's a quack "journal" advocating homeopathy. I can't see how this article can be taken seriously if NSN is cited. Man i hate chemisry.

Coenzyme or cofactor?

This page says that TPP is a coenzyme, but I've read that it is in fact a cofactor of pyruvate dehydrogenase, and a coenzyme of transketolase. I'm confused. Anyone have any ideas?

In both cases, the term "coenzyme" seems the most appropiate.

You are right. It is a prosthetic group. --kupirijo (talk) 00:06, 25 November 2008 (UTC)

Diabetes and Thiamine testing

I don't feel qualified to try to incorporate this, but here's an article describing research which found that diabetics tend to be significantly thiamine deficient, which may in fact cause many of the serious symptoms of diabetes.

The article also says that transketolase may not be a good diagnostic tool, but I could be misreading that. Blurble 14:48, 9 August 2007 (UTC)

History of vitamins....

I hope someone more wiki-skilled than I will incorporate things drawn from....

http://nobelprize.org/educational_games/medicine/vitamin_b1/eijkman.html

.. and similar into this page about thiamine.

I understand from a BBC TV program that Carol Vordeman's great-grandfather Vorderman (I think the absent/ extra "r" are correct) was chief medical officer for the whole "Dutch East Indies" (today's Indonesia)... and noticed the link between beriberi and white (polished) vs brown rice.... a difference that was especially important to prisoners, who ate white rice... and died... in their millions...

Supposedly the current head of the Eijkman institute... named for the man who got the Nobel prize for "discovering" B1 has said that Vorderman should have shared that prize.

Tkbwik 20:50, 27 September 2007 (UTC)

I was reviewing and thiamine is not an amine so this is why it is also known as thiamin. A move away from confusing and false nomenclature (thiamine) to thiamin makes sense to me, more sense then continuing with a historical naming error. — Preceding unsigned comment added by Dwot (talk • contribs) 23:14, 5 November 2016 (UTC)

References

New article request (genetic diseases section of article)

I would say that if this particular section becomes too long, then one could make a new article, but the suggested name seems a bit too long. It might make sense to eventually make an article with a name something like "Genetic diseases of thyamin metabolism," but right now there doesn't seem to be enough material for that. Someone else would just come along and want to merge it back into this article.
WriterHound (talk) 14:24, 28 April 2008 (UTC)

No mentioning of "function" of thiamine?

There's only a sentence in the lede that says it's "essential for neural function and carbohydrate metabolism", which is pretty vague.

This page, I believe, provides the primary information needed, and I will try to incorporate some of the information into the article if no one else gets there before I had the time to do so.Keith Galveston (talk) 09:07, 29 June 2008 (UTC)

Bryan Elliott: Thanks for that; I was looking for the role of thiamin in human metabolism when I pulled up this article. I'll see if I understand what's linked here, and create a sub-stub once I've grokked it. (edit) oooo, page not found. The search continues....

Recent Edits

I welcome discussion/improvements to the material I added. Is it OK to use Google Scholar as a general reference to support overview statements instead of attempting to select specific references that appeal to my POV?shbrown (talk) 14:32, 17 August 2008 (UTC)

Thiamin(e)?

Is there any consensus about how the name of the compound should be spelled in the article? Both "Thiamine" and "Thiamin" are used right now. It's confusing. (Google returns some 2,210,000 results for "Thiamin" and some 3,160,000 results for "Thiamine", if it's worth anything.) Tim Song (talk) 03:33, 16 September 2008 (UTC)

I just came here to express the same concern. Google counts are worth something, but those are too close to be meaningful. The article title is Thiamin, which is also worth something, but not definitive. My spellchecker want to go with "thiamine", FWIW. Is there some chemists convention where "thiamine" is used in some special case? If so someone should come and fix that. Right now I see "thiamine deficiency" in one paragraph and "thiamin deficiency" in another. I am changing all to "thiamine".  Randall Bart   Talk  22:31, 7 October 2008 (UTC)

I think it should be called "thiamine". See the History section of the article for the rationale. It contains an amino group, i.e., an amine, so one would logically expect the English spelling to be "thiamine". The scientific papers and publications used as references in the article appear to use "thiamine" more often than "thiamin". (Incidentally, the spelling checker in the Linux-based browser I am using to write this comment prefers "thiamine".) I'd recommend changing all instances of "thiamin" to "thiamine", except where it appears in a reference title or direct quote from a reference source, speedy deletion of the Thiamine redirect, and moving Thiamin to Thiamine. —Quicksilver^{T @} 19:41, 28 February 2009 (UTC)

I agree that it should be called "thiamine" as it contain an amine function. Furthermore, I recommend that thiamine phosphate derivatives be abbreviated ThMP, ThDP, ThTP... as the abbreviations often used, even in the scientific literature, TMP, TDP and TTP are already the official abbreviations of the thymidine phosphate esters thymidine monophosphate, thymidine diphophate...Lulubou (talk) 16:24, 2 March 2009 (UTC)

"Thiamine" seems to be the more common spelling compared to "thiamin" in both the scientific literature and in common use. The consensus here seems to be to move the article back to "thiamine", so I have done so. I have also switched to a consistent use of "thiamine" throughout the article. There were cases where the spelling switched between the two spelling variations within the same sentence. ChemNerd (talk) 17:35, 2 March 2009 (UTC)

As evidence to support the recent move from thiamin to thiamine, I searched ISI Web of Knowledge:

• "thiamin": 5013 results
• "thiamine": 19,216

Good move

Ben (talk) 22:42, 2 March 2009 (UTC)

Google search returns are hardly an accurate measure of what is right and does NOT indicate proper usage of thiamin/thiamine. To quickly resolve this “confusion”: Thiamin is the US or "American" spelling while thiamine is the British or European spelling. Thiamin, aka "Vitamin B1," is the proper way to spell it in America.

http://spelling.org/free/instructional/british_vs_american_spelling.htm http://www.healthline.com/sw/sns-thiamin —Preceding unsigned comment added by AllanRutenberg (talk • contribs) 19:18, 13 March 2009 (UTC)

The British government spells it "thiamin."[1]

Let's look at official (edit: US) government websites.

• "thiamin": 16,300 results[2]
• "thiamine": 48,700 results[3]

And yet, "thiamin" is how it's spelled on all US nutrition labels, which is the most prominent place where it's ever spelled.

British government websites:

• "thiamin": 3,150 results[4]
• "thiamine": 827 results[5]

The UK doesn't enforce a uniform label the way the US does, but here's a label for British baby food (the only label I could find that included vitamins) and it's spelled "thiamin":[6]. I'm pretty sure most people know of thiamin primarily from food labeling, so I would argue for changing the name to what people are most familiar with, since both US and UK governments are at least ok with either spelling, regardless of which may be preferred. 67.100.126.137 (talk) 22:05, 14 May 2010 (UTC)

I'd like to direct everyone's attention to an article that attempts in brief to address this exact issue in the introduction[7]. The argument is that the e was dropped when it was discovered that thiamin is in fact, not, an amine. It is therefore stated the thiamine is an archaic spelling that is gradually falling out of use. With this in mind, perhaps it would be best to revert the article title and all instances within the article to thiamin? Annicorn (talk) 23:14, 30 August 2016 (UTC)

I agree with these latest comments in support of thiamin (without the e). In addition, the recent authoritative history of thiamin -- Kenneth Carpenter's "Beriberi, White Rice, and Vitamin B" (University of California Press, 2000) -- states (p. 113) that thiamin is the correct modern spelling, and notes that the older spelling "thiamine" is gradually being abandoned. We also find "thiamin" uniquely in/on 1. the USDA website; 2. the NIH website; and 3. Wardlaw's standard textbook Perspectives on Nutrition, 4th edition. I think it's pretty clear that although both spellings are permissible, "thiamin" should be preferred as more contemporary and accepted by specialists. Will someone please now make the necessary change? Ajrocke (talk) 12:54, 31 October 2016 (UTC)

Ajrocke, thank you for the source. Dr. Carpenter is definitely an authority. He writes for the Nobel Prize committee and Britannica. I hope he also writes for Wikipedia. 😃 Thiamin is the modern spelling. At first I thought it was a UK/US difference but UK NHS also spells it thiamin. We will move the article, @Doc James: willing. -SusanLesch (talk) 15:36, 3 May 2018 (UTC)

This move requires an administrator so is waiting for Doc James. It's a fairly involved operation to change every occurrence and sub-article. I have changed the spelling in this article, and kept the archaic form in the titles of citations and in quotations. -SusanLesch (talk) 16:01, 3 May 2018 (UTC)

Not seeing consensus for a move. Please open a WP:RM.Doc James (talk · contribs · email) 01:42, 4 May 2018 (UTC)

Done. Thank you. -SusanLesch (talk) 14:01, 4 May 2018 (UTC)

The 2010 tallies of spelling on U.S. and British government websites was, I think, quite useful, notwithstanding the general caution required around search engine tests. (It would be worthwhile to update those tallies every decade or so, I suspect.)

I suggest that if there's any validity to the claims made above about the history of usage of the different spellings, that they be included in the article, along with a note about regional preferences.

—DIV (49.179.81.96 (talk) 12:01, 25 June 2022 (UTC))
Support good-faith IP editors: insist that Wikipedia's administrators adhere to Wikipedia's own policies on keeping range-blocks as a last resort, with minimal breadth and duration, in order to reduce adverse collateral effects; support more precisely targeted restrictions such as protecting only articles themselves, not associated Talk pages, or presenting pages as semi-protected, or blocking mobile edits when accessed from designated IP ranges.

Adding content to an old discussion (started 2008, last prior contribution 2018) is unlikely to be seen by other editors. David notMD (talk) 14:16, 25 June 2022 (UTC)

Thiamine Chemical Formula

Thiamine is listed in this page as having a chemical formula of C12-H17-N4-O-S, which gives a molecular weight of 265.31. This is the thiamine cation however. "Thiamine" is listed in both the Merck Index as well as the United States National Library of Medicine has having a molecular formula of C12-H17-N4-O-S.Cl, which includes the chloride anion ([8]) —Preceding unsigned comment added by Anemone13 (talk • contribs) 19:39, 18 January 2010 (UTC)

Formula listed today (22-Nov-2013, Melbourne Australia time) has Cl in it, but there is no Cl in the structure provided in Wikipedia. Need to be consistent. Can anybody add what the state of thiamine is for the purposes of reporting nutritional values in food, ie infant formula. — Preceding unsigned comment added by 58.178.183.180 (talk) 04:52, 22 November 2013 (UTC)

Thiamine Mononitrate

Thiamine Mononitrate is the form of thiamine I see listed in supplement ingredients, how come it only gets a passing mention in the article? What other bio-active forms are there? — Preceding unsigned comment added by 184.191.224.10 (talk) 21:12, 25 January 2012 (UTC)

The mononitrate part of the molecule is for stability when thiamine is added to food or an ingredient in a supplement. It separates during digestion and is not part of what is absorbed as thiamine. For some vitamins and essential minerals there are heated debates as to whether the accessory part of the compound aids or hinders absorption, but I do not believe that applies to thiamine. David notMD (talk) 01:07, 2 September 2017 (UTC)

Exact mass?

It might make sense to calculate an exact mass for biomolecules using the lightest and most common of the nuclides to do it. This would then be the most common peak in mass spectrometry. It is a nine significant digit number since we know the atomic weights of the various nuclides to that accuracy. However, real samples will have a mean molecular weight accurate to less than 6 sig digit certainty, due to natural variations in C-12/C-13 ratios and so forth, depending on the source of the molecule (this is how testosterne doping is detected in sports, for example). If we put "exact masses" in these articles to 9 digits, we should make it clear how they are calculated by assuming the most common nuclides for each atomic species. That isn't a given-- for assuming most common nuclide isn't part of the definition of "exact mass" for molecules (for example, a molecule of thiamine which appened to contain an atom of C-13 would have quite a different exact mass than the one you see here). So there needs to be a footnote and caveat, to the effect that this is the assumption made for these figures for any molecule, and particularly biomolecules. SBHarris 16:38, 11 April 2012 (UTC)

Need a photo of the stuff

Can we get a picture of it on here? Warpzero 05:36, 19 June 2012 (UTC)

Yeah, we should have one. It's an uninteresting-looking white powder, but we have plenty of photos of white powders in chem articles. SBHarris 01:07, 21 June 2012 (UTC)

Whatever happened to G6P Dehydrogenase

I always thought that thiamine as a cofactor for G6PD was an essential part of understanding the necessity of replacing thiamine with dextrose infusion in alcoholics. This seemed to be common knowledge in the 20th century. What happened? doctorwolfie (talk) 12:50, 13 March 2014 (UTC)

"Thiamine is used in the biosynthesis of the neurotransmitters acetylcholine and gamma-aminobutyric acid (GABA)"

I've removed this sentence since thiamine does not participate directly in these syntheses. The thiamine derivative TPP is used as a cofactor in the citric acid cycle and acetyl CoA production to produce acetyl-CoA and alpha-ketoglutarate(which can be converted to glutamate). Acetyl-CoA is used in the synthesis of acetylcholine, and glutamate is a precursor to GABA, so decrease of thiamine does lead to decrease in these neurotransmitters... But it also leads to a decrease in the synthesis of a whole lot of things due to the fact that acetyl-CoA production and the citric acid cycle are so central to metabolism in general.TypingAway (talk) 03:08, 6 May 2015 (UTC)

Dietary Reference Intakes

I am creating the same format for DRIs for all B vitamins. That is a U.S.- based system that identifies Estimated Average Requirements (EARs), Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs) if there is not enough information to establish EARs and RDAs, and Tolerable Upper Intake Levels (ULs). Another major regulatory agency that has established ULs is the European Food Safety Authority (EFSA). ULs for both are provided, as they often differ. If there is a UL (for some vitamins none has been determined) then rationale is covered in a Toxicity section. In addition to DRIs, the U.S. also established Daily Value, using it on food and dietary supplement labels as %DV, last revised in May 2016. What I have written can be improved. It lacks EFSA or other major country RDAs. It lacks an estimate of what percentages of people are deficient - although that is often covered in a separate section on deficiency and consequences of deficiency. I am creating this Subject in all of the Talk pages of the vitamin entries I have edited. Comments and improvements are welcome. David notMD (talk) 14:15, 2 March 2016 (UTC)

Food and supplement labeling for Daily Values will confusing for several years. The entire Facts panel was revised May 2016, but companies have until July 28, 2018 to be compliance with the change (small companies, a year longer). This means that products will be for sale with old or new %DV determinations.David notMD (talk) 17:25, 9 July 2016 (UTC)

Changed section title to Dietary recommendations because Dietary Reference Intakes is used only in U.S. and Canada; added European information, with citations. David notMD (talk) 12:56, 31 August 2017 (UTC)

The lede

My intention in removing the two sentences about cost of product is that those apply only to injectable, prescription product. In my opinion, most people visiting this entry are thinking about the vitamin as an oral product. Either the two sentences should be modified to be clearer about injectable, or deleted (my preference). Secondly, the sentence about some countries adding thiamine to grains is vague. The sentence I added - since deleted - provides more detail about the amount of fortification in the United States. Information could be added about other countries. This reference could be added. Again, in my opinion that would make for a stronger lede.

https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=137.165

David notMD (talk) 17:20, 1 April 2017 (UTC)

Injectable vitamin products are commonly used for many indications. They are the recommended treatment for alcoholic induced thiamine deficiency at least initially.

Clarified that the second bit was about by mouth while the first is a vial which can be taken by mouth but also by injection. Doc James (talk · contribs · email) 02:22, 2 April 2017 (UTC)

We are still at cross purposes, but I do not know how to resolve it. Food/supplement grade thiamine HCL or thiamine mononitrate is priced at $.20 to $1.00 per gram, depending on which compound and amount. Given 100% DV (U.S.) is 1.2 mg/day, a month's supply costs just pennies. I am still of the opinion that having two sentences about cost here (and in the riboflavin entry) serve no benefit. David notMD (talk) 13:06, 2 April 2017 (UTC)

Added text to differentiate between food/supplement grade and medical products. David notMD (talk) 21:44, 7 April 2017 (UTC)

Not sure why you repeated "often by intravenous or intramuscular injection, but also orally" in paragraph 3 of the lead when paragraph 1 already says "It is taken by mouth or by injection."?

Which ref supports "used as an ingredient in food fortification and dietary supplements at an ingredient cost of pennies per day"? I am not seeing that in the AHFS source. We can add it we just need a source and it should likely go with the existing sentence on fortification.

Doc James (talk · contribs · email) 07:32, 10 April 2017 (UTC)

Why have pricing information?

In looking at the leads for all of the vitamins, most have no mention of cost. Would these articles be better if none mentioned cost? Or if all used the same source? Vitamin C states 3-7 cents per 100 mg tablet, referenced to: International Drug Price Indicator Guide. Management Sciences for Health, Arlington, VA. 2016. Folate and Vitamin B1 cite the same source, but the hyperlinks do not work. Vitamins B1 and B2 reference a text without a hyperlink [Hamilton, Richart (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. 230. ISBN 9781284057560.] which appears to apply to hospital prescription pricing, as the costs are far higher than vitamin supplement pricing. My preference is for no mention of cost. David notMD (talk) 10:44, 5 August 2017 (UTC)

How much medications cost, especially those on the WHO List of Essential Medicines is important with respect to global health. Doc James (talk · contribs · email) 23:14, 5 August 2017 (UTC)

The WHO List has only nine nutrients, and no cost per dose information. The vitamin C article is the only one with a functioning link to a cost. Link is http://mshpriceguide.org/en/single-drug-information/?DMFId=830&searchYear=2015. Changing the 830 to 821 gets working link to vitamin B1, to 827 gets B6. This MSH Price Guide does not have much more in the way of cost per day. Again, given paucity of on line information, my opinion is to still list nothing for any nutrient. More to the point, providing a hospital pharmacy charge for a nutrient has no relevance for a person who is looking at the article and wondering how much the nutrient would cost at a retail pharmacy. David notMD (talk) 12:58, 6 August 2017 (UTC)

All the pricing information is well referenced. As medicines vary in price by more than a 100 million times yes the rough price of medicines is useful. Is the med around one USD, 10 USD, 100 USD, 10,000 USD etc? Also we are not just writing for potential patients by also hospital admin and health systems. Doc James (talk · contribs · email) 15:38, 6 August 2017 (UTC)

I disagree, but am not going to change any of the vitamin articles. David notMD (talk) 10:50, 7 August 2017 (UTC)

We had a big discussion at WT:MED about this a year or two ago. IMO price is an important dimension of a medication. The price of hepatitis C meds for example are notable. This often determines whether or not a medication can be found in a country and whether or not a person is able to get the treatment in question. Doc James (talk · contribs · email) 16:29, 7 August 2017 (UTC)

Thiamin is a vitamin

Hello. User:Doc James undid all of my changes and not for the better. The first paragraph should be about the vitamin. This is first and foremost what thiamine is. You are welcome to discuss supplements later on. I do not want to participate in a conversation about this. -SusanLesch (talk) 20:08, 10 April 2018 (UTC)

Thiamine is both a vitamin and a supplement and the first sentence should mention this.

Have mentioned the sources as the second sentence. Its use as a supplement is important.

Doc James (talk · contribs · email) 06:37, 11 April 2018 (UTC)

The function of the substance must be established first, before stating signs of its deficiencies. I am going to try again. -SusanLesch (talk) 17:57, 11 April 2018 (UTC)

It is very important as a supplement. I disagree with the changes that de emphasizes this importance.

This article is also about thiamine not thiamine deficiency. Thus mentioning that thiamine deficiency is rare in the USA before even discussing that thiamine is used to treat the condition is strange.

And why are we discussing how common thiamine deficiency is in the lead of this article? What about other countries or globally?

Bunch of the additions such as "It functions as a cofactor for five enzymes involved in glucose, amino acid, and lipid metabolism, and is involved in membrane and nerve conduction." are also unreferenced. Doc James (talk · contribs · email) 19:32, 13 April 2018 (UTC)

My time for Wikipedia is extremely limited right now. You're right about sourcing functions. And I agree, prevalence shouldn't be stated in terms of a US-centric source.

Still this article's lead is unbecoming of an M.D. The first paragraph ends, "It is taken by mouth or by injection." Detail belongs in the article prose. All three of these statements belong in prose and not in the lead:

• It is taken by mouth or by injection.
• Side effects are generally few.
• Allergic reactions, including anaphylaxis, may occur.

In my country, people are encouraged to get most of their nutrients from food. Britannica says, "In Western countries, thiamin deficiency is encountered almost solely in cases of chronic alcoholism." Maple syrup urine disease occurs in 1 in 185,000 births. That means subordinate them to the main topic which is essential to everyone. -SusanLesch (talk) 23:28, 13 April 2018 (UTC)

Discussion of side effects are just an important as effects.

We use easier to understand language per WP:MEDMOS

This "that functions in the nervous system" implies that it only needed in the CNS which is not true.

Also not a big fan of the one sentence paragraph you created in the lead.

Doc James (talk · contribs · email) 05:50, 14 April 2018 (UTC)

What was wrong with this? "Some countries require its addition to certain foods such as grains." Only required of a few vitamins / substances. Doc James (talk · contribs · email) 05:57, 14 April 2018 (UTC)

Side question. Going by Wikipedia, why is it so important to you to list a sequela of Wernicke's encephalopathy in the first paragraph of a lead about thiamine? If Wikipedia is in error, then perhaps you would fix the article Wernicke–Korsakoff_syndrome. More later. -SusanLesch (talk) 14:30, 14 April 2018 (UTC)

Not sure what you mean? Sure Wernicke–Korsakoff_syndrome needs work. Doc James (talk · contribs · email) 17:12, 14 April 2018 (UTC)

Restating my question. Why do you insist on listing Korsakoff psychosis in the first paragraph of the lead of this article about thiamine? Apparently Korsakoff psychosis is a late complication of persistent Wernicke encephalopathy.... -SusanLesch (talk) 17:28, 14 April 2018 (UTC)

Yes that is a good point and have adjusted per the ref.[9] Doc James (talk · contribs · email) 17:38, 14 April 2018 (UTC)

Better source?

Why is this not a good enough source? "American Society of Health-System Pharmacists" Doc James (talk · contribs · email) 09:09, 18 April 2018 (UTC)

Failed verification

When I updated the Drugs.com reference to a live url, I checked every statement that it sourced. These two statements are not present in Drugs.com or in the NIH factsheet. I take issue with User:Doc James reverting my verification tags, and then not fixing the problem. I have re-added those tags.

• "Side effects of thiamine supplements are generally few."

If you're going to characterize the quantity of possible side effects, you will need a source that gives an assessment of the quantity. The source does not do that. https://www.drugs.com/monograph/thiamine-hydrochloride.html Then you added a quote that characterizes the toxicity. Toxicity is a separate attribute. "quote = Relatively nontoxic"

• "Thiamine is an essential nutrient, as people are unable to make it."

https://web.archive.org/web/20161230231520/https://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/ I would love to see a source actually say that people can't make thiamin. But this one does not say that. Nor does the previous source you gave. Neither one actually says thiamin is an essential nutrient either. https://www.drugs.com/monograph/thiamine-hydrochloride.html -SusanLesch (talk) 19:23, 21 April 2018 (UTC)

Okay so is thiamine an "essential nutrient"? This ref says "inadequate intakes of essential nutrients, including thiamin"[10]

Second part, can humans made it internally?

"Thiamine (vitamin B1) is synthesized only in bacteria, fungi, and plants but is an essential nutrient for animals."[11]

Doc James (talk · contribs · email) 13:45, 22 April 2018 (UTC)

You're right NIH did say thiamin is an essential nutrient. My apologies for reading only the part about alcohol abuse where they said so. Why didn't you reply to the first part of my comments? I shouldn't have to repeat a request for correction. -SusanLesch (talk) 15:51, 22 April 2018 (UTC)

The ref says "Relatively nontoxic"[12]

This supports "Side effects of thiamine supplements are generally minimal"

Doc James (talk · contribs · email) 18:00, 23 April 2018 (UTC)

You can't really believe that an expression of quantity ("few" now changed to "minimal") equates to an expression of toxicity ("Relatively nontoxic"). I will need to seek an outside opinion if you can't understand the difference. Would you prefer that I follow up to Wikipedia talk:WikiProject Medicine, Wikipedia:Third opinion, or Wikipedia:Dispute resolution noticeboard? -SusanLesch (talk) 18:10, 23 April 2018 (UTC)

"few" and "minimal" equates to "relatively non" ie relatively nontoxic. So yes it was fine and yes you are welcome to request further opinions.

This is not a controversial statement and we have lots of potential sources. Doc James (talk · contribs · email) 06:18, 24 April 2018 (UTC)

Question

Can:

a) "Relatively nontoxic"[13]

be reasonably summarized as

b) "Side effects of thiamine supplements are generally minimal"

Doc James (talk · contribs · email) 06:20, 24 April 2018 (UTC)

seems reasonable, would agree with "b"--Ozzie10aaaa (talk) 10:23, 24 April 2018 (UTC)

We also have this ref that says the same sort of thing using different language.[14]

"There are no reports of adverse effects..." except some when used by injection. Doc James (talk · contribs · email) 06:31, 24 April 2018 (UTC)

Doesn't choice A speak to the direct effects of Thiamine while choice B addresses its side effects instead? I think there's a difference there. SEMMENDINGER (talk) 12:57, 24 April 2018 (UTC)

Its fine. There are few adverse effects of thiamine when used as a supplement- this is what the source says. Jytdog (talk) 15:45, 24 April 2018 (UTC)

• User:SusanLesch i just reviewed the changes to this page. It seems that you are concerned about what happens when people take too much - is that the issue? We could easily add something on that. Jytdog (talk) 15:48, 24 April 2018 (UTC)

Hi @Jytdog: Thanks for asking. No I'm not worried about people taking too much. "Thiamin has not been shown to cause any harm." But I do worry when the English language gets thrown out the window. "are generally minimal" used to say "are generally few". Both are characterizations of quantity. (Like big, or a lot, or none.) We do not have the right to equate measures of quantity with measures of toxicity (the given source only specifically addressed the latter). Now James has added a new source which isn't great but it is acceptable. -SusanLesch (talk) 16:42, 24 April 2018 (UTC)

OK thanks for clarifying. Jytdog (talk) 16:49, 24 April 2018 (UTC)

I dislike the phrase "relatively nontoxic". "Nontoxic" should be a binary situation; either a chemical is nontoxic or it is not nontoxic. The source should have stated something like "relatively low toxicity".

SusanLesch argues that "generally few" and "generally minimal" are characterizations of quantity. This is correct. However, use of the word "relatively" in the phrase "relatively nontoxic" implies that this phrase is also a characterization of quantity. On the other hand, "nontoxic" is not suitable as a quantitative adjective. Axl ¤ [Talk] 10:45, 26 April 2018 (UTC)

Would "Thiamine supplements are generally well tolerated." be better? Doc James (talk · contribs · email) 14:12, 26 April 2018 (UTC)

Fine by me. Axl ¤ [Talk] 18:34, 26 April 2018 (UTC)

I agree with "generally well tolerated".JenOttawa (talk) 22:01, 27 April 2018 (UTC)

American Society of Health-System Pharmacists is a better source than Mayo and per this discussion supported the text. I thus restored that source. Doc James (talk · contribs · email) 21:39, 30 April 2018 (UTC)

Hold on. This discussion didn't establish any opinion on ASHP/Drugs.com as a source. You just kept changing the wording until it wasn't objectionable. Why on earth would I agree that ASHP is any better than the Mayo Clinic? -SusanLesch (talk) 23:24, 30 April 2018 (UTC)

AHFS is a perfectly suitable source. Thus restoring it. Not seeing consensus that AHFS is not a suitable source. Doc James (talk · contribs · email) 01:38, 4 May 2018 (UTC)

We use AHFS on many MANY articles; it is MEDRS. Mayo and other university/hospital websites are not MEDRS. This was considered at WT:MEDRS a long time ago and ruled out there. The reason is that these cites are very uneven, are not peer reviewed, etc. Jytdog (talk) 02:56, 4 May 2018 (UTC)

Forgive me, Doc James. I will use the WT:MEDRS archive in the future. Thank you very much, Jytdog. -SusanLesch (talk) 13:14, 4 May 2018 (UTC)

Injection being prescription

Which source supports this? Also what is prescription or not is very jurisdictional. Doc James (talk · contribs · email) 23:19, 28 April 2018 (UTC)

"Medication" is usually given by injection? Really. What reference supports that User:Iztwoz? Doc James (talk · contribs · email) 05:41, 30 April 2018 (UTC)

Hello Doc James Both queried items are from the ref i gave after your earlier query - in the Prescription products sections of the paper. If there's an alternative interpretation that i'm ignorant of please enlighten.--Iztwoz (talk) 08:10, 30 April 2018 (UTC)

You are referring to this ref[15]?

We often prescribe oral thiamine. The ref in question does not say that prescriptions are usually injections.

It just lists some prescription products by over the counter stuff can be prescribed.

Prescription does not equal only medication as over-the-counter is also medication. Also you will notice the products are tagged with a country logo as these distinction on country specific. Doc James (talk · contribs · email) 21:15, 30 April 2018 (UTC)

My issue with the original wording: "Supplements and over-the-counter drugs are mostly taken by mouth, and most prescription drugs are given by injection." is that it is overly detailed for the lead and specific to certain countries. Doc James (talk · contribs · email) 21:42, 30 April 2018 (UTC)

User:Doc James the ref clearly outlines the generic medications all listed as injection given, and the over the counter as oral bar one. This is the same for both countries tagged. I take your point that it's overly detailed for lead, but i think i added it there to avoid a gloss-over; and I hadn't noticed the country tag. I took it to mean that higher doses would be by injection. Also over the counter drugs in UK include the lower doses that can also be prescribed. Best --Iztwoz (talk) 13:12, 1 May 2018 (UTC)

It looks like someone has deleted the offending sentence. In any case, I also dispute the claim that "most prescription drugs are given by injection". Over-the-counter drugs can also be prescribed. The reference does not state the number of prescriptions of each form.

As an aside, the reference states that one formulation of thiamine hydrochloride IM/IV injection (David Bull Laboratories) is available over the counter. I am pretty sure that IM/IV preparations are not available over the counter in the UK. Axl ¤ [Talk] 12:41, 3 May 2018 (UTC)

Blurring the lines

There is confusion on the page in the refs to supplements and drugs. From the page Dietary supplements - supplements are always taken orally. There is no governmental control on the manufacture of supplements. Drugs are manufactured clearly with control. The sentence that was reverted about the vitamin being found in food and also manufactured as a supplement or medication made things a lot clearer. Both are extensive and separate industries/manufacturers. --Iztwoz (talk) 08:34, 30 April 2018 (UTC)

Have adjusted to "They are typically taken by mouth, but may also be given by intravenous or intramuscular injection." We already "mention supplements and medicines" in the prior two sentences so would apply in this one.

Do people use injectable thiamine supplements? Yes in alt med treatments. User:Iztwoz does that address your concerns? Doc James (talk · contribs · email) 21:25, 30 April 2018 (UTC)

Yes, thank you. But - I still think the addition of 'manufactured for use' a better point of clarification. I might make some further changes which of course you may revert.--Iztwoz (talk) 13:16, 1 May 2018 (UTC)

Sure. Adjusted. Doc James (talk · contribs · email) 01:13, 2 May 2018 (UTC)

Requested move 4 May 2018

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: no consensus to move the pages at this time, per the discussion below. Please note that support for a move by the editor proposing the change is implied, so it is not generally required to list support on a separate line in a move request that you have initiated. I have created redirects from all of the proposed titles to the current article locations. Dekimasuよ! 17:35, 10 May 2018 (UTC)

---

• Thiamine → Thiamin
• Thiamine deficiency → Thiamin deficiency
• Thiamine-phosphate kinase → Thiamin-phosphate kinase
• Thiamine diphosphokinase → Thiamin diphosphokinase
• Adenosine thiamine diphosphate → Adenosine thiamin diphosphate

– Thiamin is the modern spelling. Sub-articles will also need to move.

• Thiamine and vitamine were originally thought to be amines but neither is. The "e" in vitamin was dropped, and the "e" in thiamin is being dropped. PMID 22116701
• Dr. Kenneth Carpenter, a vitamin expert who has written for Britannica and the Nobel Prize committee (Nobel Media AB), wrote that thiamine is fading out and thiamin is the modern spelling.
• Both UK NHS and US NIH spell it thiamin illustrating that this is not a UK vs. US spelling problem. SusanLesch (talk) 13:52, 4 May 2018 (UTC)

Oppose - in 2009 the consensus (Thiamin(e) ?) was to move name to thiamine as it was the most commonly used name. That is still the case. The use of name comes down to choice not to any mandate. Carpenter's book referred to is of 2000 and to have stated that the use of 'thiamine' was fading out has clearly proven otherwise. Ngrams show double the usage of thiamine. Google hits give 5,150,000 for thiamine and 3,830,000 for thiamin. NIH the US site does use 'thiamin' but does state or 'thiamine'; also on its GARD page the choice is 'thiamine'. WHO prefers the use of 'thiamine' used 110 times in Guidelines ref on entry page. NICE.org.UK prefers 'thiamine'.and the use of all other terms including thiamine hydrochloride usually uses the name thiamine. It would still seem to be the commonly used name. To say that the original name was thiamine and the 'e' was dropped is not supported by the Nobel Prize literature which states that from its discovery in 1926 it was called 'thiamin' and in papers from the 1950s thiamine was used.--Iztwoz (talk) 15:59, 4 May 2018 (UTC)

Question Iztwoz, thank you for your comments. Where does the Nobel literature for Eijkman or anybody else discuss the spelling? -SusanLesch

It isn't discussed anywhere just stated (on the page you provide) that the vitamin was called 'thiamin'. On anther page it lists the later 1950s publications after the earlier refs to 'thiamin'.--Iztwoz (talk) 17:37, 4 May 2018 (UTC)

Here's the other info - --Iztwoz (talk) 17:42, 4 May 2018 (UTC)

References

Fair enough. Nobel Media doesn't seem to be relevant (I counted two of each spelling in your search link.) -SusanLesch (talk) 19:21, 4 May 2018 (UTC)

• Oppose WHO and FAO use thiamine.[16] Doc James (talk · contribs · email) 10:11, 5 May 2018 (UTC)
• Support. The three best textbooks I can find including Doc James's source for vitamin B3 all spell it thiamin:

• Modern Nutrition in Health and Disease
• Biochemical, Physiological, and Molecular Aspects of Human Nutrition
• Advanced Nutrition and Human Metabolism. -SusanLesch (talk) 13:27, 5 May 2018 (UTC)

• Oppose per Iztwoz and DocJames. Authoritative sources still use this spelling, and it is used more commonly than alternate spellings. Suggest renominate in a decade when use WP:COMMONNAME may finally reflect this spelling. --Tom (LT) (talk) 04:05, 6 May 2018 (UTC)

• Respecting the canon is more my cup of tea. -SusanLesch (talk) 13:38, 6 May 2018 (UTC)

• Support. WP:COMMONNAME still exists, right? Red Slash 11:59, 8 May 2018 (UTC)
  • User:Red Slash if you look at Ngram viwer thiamine is still more common than thiamin.[17] In fact it has been more common since the 1950s. Doc James (talk · contribs · email) 12:59, 8 May 2018 (UTC)

• Wikipedia has no need to put on airs, sort of like in America, Guthrie Theat-re or ye olde thiamine. -SusanLesch (talk) 14:58, 8 May 2018 (UTC)

• Umm, it was thiamin that was most common before the 1950s. Doc James (talk · contribs · email) 13:28, 9 May 2018 (UTC)

  @Doc James:, that Ngram tool is cool, thanks. Merck published The Story of Vitamin B1 in 1937, spelling it thiamin. Robert R. Williams was the biochemist who first synthesized thiamin. He called it vitamin B1 but he wrote in 1938, "The Chemistry and Biological Significance of Thiamin" (Science 24 Jun 1938: Vol. 87, Issue 2269, pp. 559-563 DOI: 10.1126/science.87.2269.559). So it started out thiamin, thiamine outnumbered that by around 1950 as you say, and nowadays the authorities spell it thiamin. If the majority wins per Ngram I have no choice but to concede. This does not change the fact that the three best textbooks on the market all use thiamin. -SusanLesch (talk) 00:41, 10 May 2018 (UTC)

• Oppose. Case not made. Thiamine appears to predominate. Wikipedia follows, it doesn’t lead. —SmokeyJoe (talk) 16:12, 9 May 2018 (UTC)

• Hold on a minute. The original name was thiamin. -SusanLesch (talk) 00:41, 10 May 2018 (UTC)

• @Doc James:, sorry but we need to take this Ngram tool into the shop. It seems to be very spotty. For example, here I asked for "vitamin B1" and "thiamin". It couldn't find vitamin B1 -SusanLesch (talk) 15:25, 10 May 2018 (UTC)

Search terms don't go in quotes on Google Ngrams, for some reason: B1 included. Dekimasuよ! 17:27, 10 May 2018 (UTC)

---

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Page number

This ref was added http://www.who.int/nutrition/publications/guide_food_fortification_micronutrients.pdf

The document is more than 300 pages. Which page supports the text in question?

"Refined grains lose much of their thiamine and in many countries cereals and flours are enriched with thiamine."

Doc James (talk · contribs · email) 10:12, 5 May 2018 (UTC)

References

Done --Iztwoz (talk) 10:49, 5 May 2018 (UTC)

Foundations 2 2019, Group 5a goals

Elaborate upon the importance of thiamine in pregnancy and explain why pregnant/lactating women have higher DRIs. Discuss the consequence(s) of thiamine deficiency in pregnant women, newborns, lactating women, and breastfeeding infants.

Mlomanto (talk) 21:31, 30 July 2019 (UTC)

Foundations 2 2019, Group 5c Peer Review of Group 5b

1. Do the group’s edits substantially improve the article as described in the Wikipedia peer review “Guiding framework”?

The article mainly expands upon thiamine as prenatal nutrition, specifically the reason for increased intake in pregnant and nursing women. The lead section appears easy to understand and the structure is somewhat clear as it touches upon pregnant women, pregnant women with a comorbid condition, and finally lactating women. The rest of the edits appear to be contributing, though minor (e.g. definitions, function clarifications, some side effects). The articles cited are from reliable sources, most are accessible, but some requires to be purchased for the full version (such as #19 and #36)

2. Has the group achieved its overall goals for improvement?

The group has elaborated on why pregnant and lactating women have higher DRIs including common doses of thiamine in prenatal vitamins. However, the consequences of thiamine deficiencies in the demographics listed in the goals were not clarified. The group added a new subheading under “Medical Uses” titled “Prenatal supplementation,” which elaborates on the importance of thiamine supplementation in pregnancy. Under this subheading, the group used freely accessible publications that support their statements regarding the importance of thiamine in these populations and consequences of thiamine deficiency in infants. More information could be added on the effects of thiamine deficiency in pregnant/lactating women.

3. Are the points included verifiable with cited secondary sources that are freely available? If not, specify...

The sources used by the group are mostly secondary literature that are freely accessible to the public and are supportive of their statements. Vicknguy (talk) 16:30, 6 August 2019 (UTC)

4. Are the edits formatted consistent with Wikipedia’s manual of style? If not, specify...

The edits have clear structure. A new section about thiamine as a prenatal supplement was created which makes it easier for readers to find and understand this information. All other sections are also organized in a logical order. Msleee (talk) 16:34, 6 August 2019 (UTC)

5. Has the group achieved its overall goals for improvement? If not, specify…

The first two goals were discussed, but the third was not as much outside of thiamine function and importance (or at least the edits are not showing up for me). Also, under the prenatal supplementation section: “Women who are pregnant or lactating require more thiamine. In pregnancy, this increased is likely due to [...].” Did you mean ‘increase’ or ‘increased need’? Snselim (talk) 16:41, 6 August 2019 (UTC)

6. Is there any evidence of plagiarism or copyright violation? If yes, specify...

No evidence of plagiarism or copyright violations, claims are sourced and cited appropriately. Storm1625 (talk) 16:35, 6 August 2019 (UTC)

Hello, thank you for your comments! I have attempted to address any concerns brought up in this review.

• Regarding references 19 and 36 not being freely available, the information used from reference 19 can be found in the freely available abstract. I have not personally had any issues accessing reference 36.
  
• Thank you for pointing out that I had not fully completed my last goal. had only explicitly addressed the consequences of thiamine deficiency in newborns and infant development. I have now clarified that the consequences of thiamine deficiency are not different in pregnant/lactating women, but they have an increased risk of developing these conditions.
  
• I have also fixed the typo and changed the sentence under the prenatal supplementation section to read “Women who are pregnant or lactating require more thiamine. In pregnancy, this increased need is likely due to [...].” Mlomanto (talk) 17:32, 6 August 2019 (UTC)

FDA terms AI and UL?

FDA(?) acronyms AI and UL are used without explanation. Average intake and Upper limit? — Preceding unsigned comment added by 80.254.154.105 (talk) 12:18, 23 September 2019 (UTC)

prodrugs

Benfotiamine and sulbutiamine as nutraceutical thiamine prodrugs may warrant mention in supplementation/uses. Deferring to other editors. SloppyTots (talk) 23:17, 24 October 2021 (UTC)

Benfotiamine and Sulbutiamine exist as articles, as does Fursultiamine. All are synthetic derivatives of thiamine, with claims for superior bioavailability. Approved as drug or dietary supplement in some countries. Clinical trial evidence appears to be thin. David notMD (talk) 10:06, 2 February 2022 (UTC)

Copyright violation?

Thiamine, as it exists on 31 January 2022, has a high content match with https://med.libretexts.org/LibreTexts/American_River_College/General_Nutrition_Textbook_(not_Plant-Based)-_reference_for_NUTRI_303_(Hagenburger)/7%3A_Vitamins/7.3%3A_Water_Soluble_Vitamins/Vitamin_B1. Thus, registering as a copyright violation. Medicine LibreTexts appears to be a site that copies Wikipedia articles. At its article: "Vitamin B1 (Thiamine) Last updated Aug 14, 2020", it does not acknowledge being copied from Wikipedia. David notMD (talk) 15:26, 31 January 2022 (UTC)

GA nomination

Beginning review for GA nomination. Starting with reviewing all refs that are available online. Sections will be retitled and ordered to align with other vitamin articles that are GA. David notMD (talk) 09:45, 2 February 2022 (UTC)

Nominated on 16 July 2022. Intention is to do some more work prior to review. David notMD (talk) 15:42, 16 July 2022 (UTC)

Thiamin versus Thiamine, revisited

Another way to look at this question is asking what is the preferred spelling in science journal articles. A quickie look at articles listed at the National Library of Medicine search site PubMed showed a preference for thiamine. Unfortunately, trying to search on the two spellings yielded 19,066 articles for both, meaning that PubMed sees both as one search term. David notMD (talk) 14:23, 25 June 2022 (UTC)

GA Review

This review is transcluded from Talk:Thiamine/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Mertbiol (talk · contribs) 16:00, 1 October 2022 (UTC)

I will take on this review. Here are some comments on the first part of the article. I will add more in due course. Best wishes Mertbiol (talk) 16:00, 1 October 2022 (UTC)

Lead section

• I suggest changing "which" to "that" in the first sentence.
• I suggest moving "Thiamine is required for metabolism including that of glucose, amino acids, and lipids." so that it becomes the third sentence of this section.
• I suggest rephrasing "Thiamine is required for metabolism..." to "Phosphorylated forms of thiamine are required for metabolism..."
• I suggest starting a new paragraph with "Food sources of thiamine include..."

Infobox

• I suggest rephrasing the figure caption so that it reads "Skeletal formula and ball-and-stick model of the thiamine cation".
• Please link "cation" to Ion#Anions_and_cations.

Definition

• I suggest rephrasing the first sentence so that it reads "Thiamine is one of the B vitamins and is also known as vitamin B₁."
• I know what you are trying to say when you write " thiamine is only one chemical compound", but you may confuse lay readers later in the page, when you discuss the different phosphorylated forms of thiamine.
• Please link folate, vitamin B6 and vitamer.
• I suggest moving the content of the "Chemistry" section to this section. (Please merge the content so that discussion of thermal stability and the chloride salt are not repeated.)

Deficiency

• Would "symptoms" be better than "signs" in the first sentence? Or perhaps rephrase as "Thiamine deficiency may be accompanied by malaise, weight loss, irritability and confusion."
• Would the second sentence be better placed as the first?
• Please avoid repeating "Thiamine deficiency" in the first two sentences.
• "In Western countries, chronic alcoholism is a secondary cause." Secondary cause of what?
• Please link HIV/AIDS and diabetes.

Chemistry

• Please combine this section with the "Definition" section.

Functions

• I suggest renaming this section to "Biological functions"
• Some of this section is difficult to read for non-specialists. It might be worth trying to reformat some of this material into a table.
• Would it be possible to provide skeletal formulae for the phosphorylated forms? Perhaps @Michael D. Turnbull: might be able to help out here?

 Done. Gallery could be tweaked to make the diagrams more consistent. For now I've just taken the images from the respective articles. Alternative versions would be easy to draw: or could just use ROP(=O)(OH)₂ type of drawing, although readers may be less confused with the full images. Mike Turnbull (talk) 19:43, 1 October 2022 (UTC)

Medical uses

• Please remove the subsection heading "Prenatal supplementation".
• Please link fetus, placenta.
• Please link "third trimester" to Pregnancy#Third_trimester, "lactating" to lactation, "mitochondrial membrane" to mitochondrion and "synaptosomal membrane" to synaptosome.
• Would "synaptic membrane" be better than "synaptosomal membrane"?
• I suggest rephrasing "It has also been suggested that thiamine deficiency plays a role in the poor development of the infant brain that can lead to sudden infant death syndrome (SIDS)" to read "It has also been suggested that thiamine deficiency hinders brain development in infants and may be a cause of sudden infant death syndrome (SIDS)" or similar.

Dietary recommendations

• Please decide if you are going to abbreviate United States as "US" or "U.S."
• Please link National Academy of Medicine.
• I suggest linking "Reference Daily Intake" to Reference Daily Intake or to Dietary Reference Intake.
• Please expand the acronym "IOM" and link to National Academy of Medicine. Why is "IOM" used and not "NAM"?
• Please change "In the case of Riboflavin" to read "In the case of Thiamine".
• Please link Dietary Reference Intake and remove "(DRIs)", which is not used elsewhere.
• Please change "The EFSA" to "EFSA".

Table

• Please move the table up to the top of the Dietary recommendations section.
• Please change "United States" to identify the body responsible for determining the RDAs (I presume that this is the US National Academy of Medicine).
• Please use a small "i" for "intake" in "Adequate Intake".
• I suggest removing the "tolerable upper intake" column and adding a note to the bottom of the table to say "neither NAM nor EFSA have determined the tolerable upper intake for thiamine" or similar.

Safety

• I suggest rewriting "Rarely, adverse side effects have been reported..." as "There are rare reports of adverse side effects..."

Labeling

• Please decide if you are going to abbreviate United States as "US" or "U.S.".
• Please add a comma after "For US food and dietary supplement labeling purposes".
• I suggest rephrasing "For thiamine labeling purposes 100% of the Daily Value was 1.5 mg, but as of May 27, 2016, it was revised to 1.2 mg to bring it into agreement with the RDA." to "Since May 27, 2016, the Daily Value has been 1.2 mg, in line with the RDA."

Sources

• Please delete "To aid with adequate micronutrient intake, pregnant women are often advised to take a daily prenatal multivitamin."
• Please delete "among different vitamins" from "While micronutrient compositions vary among different vitamins, a typical daily prenatal vitamin product contains around 1.5 mg of thiamine."

Antagonists

• Please rename this subsection to "Degredation"
• I suggest moving this subsection to either the "Absorption, metabolism and excretion" or to the "Synthesis" section.

Food fortification

• I suggest combining this subsection with the first part of the "Sources" section.

I will add further comments in due course. Best wishes Mertbiol (talk) 12:05, 2 October 2022 (UTC)

Status of the review

Hi @David notMD: I am a little concerned that you have not responded to any of the points raised above or edited the Thiamine article since I started the review. I appreciate that you have been unwell with COVID, but since 1 October you have made over 500 edits to other pages on Wikipedia. Could you let me know where things stand please? If you are unable to work on the Thiamine article, then I will have to fail the review. Best wishes Mertbiol (talk) 17:34, 7 November 2022 (UTC)

As I mentioned on David's Talk Page, I'm happy to work through the suggestions made, if he can't do so for any reason. Mike Turnbull (talk) 18:25, 7 November 2022 (UTC)

Mertbiol and Michael D. Turnbull - due to many circumstances, I have not returned to this task. I welcome Mike's offer to attack the suggestions made so far. I may be able to join the process, but do not promise. My non-response to date should not be taken to infer that I disagreed with any of the suggestions. David notMD (talk) 15:42, 8 November 2022 (UTC)

Hi @David notMD: I'm sorry that you're not able to continue to work on the article. In that case I would like to take up Michael D. Turnbull's offer to respond the review. Perhaps I can let Mike work through the article and my comments, and when he's ready, I can provide more feedback? Best wishes Mertbiol (talk) 18:18, 8 November 2022 (UTC)

Yes, I'll start on that tomorrow and look forward to dealing with any further suggestions. Mike Turnbull (talk) 18:29, 8 November 2022 (UTC)

@Mertbiol, @David notMD All done, I think, except to remove column from table, which I'm not technically confident enough to do! Please check my edits and make any new suggestions. Mike Turnbull (talk) 17:15, 9 November 2022 (UTC)

Thanks @Michael D. Turnbull: I'll have a thorough look through the article tomorrow. Best wishes, Mertbiol (talk) 20:28, 9 November 2022 (UTC)

Further feedback

Lead section

• I suggest changing "Thiamine and some of its phosphorylated forms are required for metabolism including that of glucose, amino acids, and lipids" to "In the body, phosphorylated forms of thiamine are required for some metabolic reactions, including the breakdown of glucose and amino acids." (Lipids are not mentioned in the rest of the article, so should be removed from the lead section.)
• Please change "Grain processing removes much of the thiamine content…" to "Grain processing removes much of the vitamin content…" or similar, to avoid repetition of "thiamine".
• Please change "Other uses include the treatment..." to "They are also used to treat..."

Definition

• I suggest deleting "Unlike other B vitamins including folate and vitamin B6, which occur in several chemically related forms known as vitamers".
• Please change "Within the body..." to "In the body..."
• I suggest deleting "The amino group can form additional salts with further acids."
• Please change "It is stable at acidic pH…" to "Thiamine is stable at acidic pH…".

Biological functions

• This is beyond the scope of a GA review, but I wonder if it would be possible to modify the images of the skeletal formulae of the thiamine derivatives, so that the thiamine moiety and the phosphates are highlighted in different colours? (I’m thinking perhaps a yellow circle under the phosphates and then to use another colour under the thiamine?)
• Could you redraw the ThMP, ThDP and AdThP so that the ionisation of the phosphate groups is the same please? Perhaps use the ThTPP drawing as the starting point, so that the thiamine moiety is in the same orientation and position in all five images?
• Please change "are all important in carbohydrate metabolism" to "are important in carbohydrate metabolism".
• Please change "which is a major form of energy for the cell" to "which is the major energy currency of the cell" or similar.
• Please link acetylcholine.
• Please rephrase: "ThTP was long considered a specific neuroactive form of thiamine, playing a role in chloride channels in the neurons of mammals and other animals, although this is not completely understood.[19] However, it was shown that ThTP exists in bacteria, fungi, plants and animals suggesting a much more general cellular role. In particular in E. coli, it seems to play a role in response to amino acid starvation." to "ThTP was long considered a neurone-specific form of thiamine. It is implicated in chloride channel activation in mammals and other animals, although its precise role is not completely understood. Recently, ThTP has been found in bacteria, fungi and plants, suggesting that it also has a much more general cellular role. In E. coli, it is implicated in the response to amino acid starvation." or similar.
• Please delink Escherichia coli in the AThTp section.

Medical uses

• "Pregnant women require more thiamine..." More thiamine than who? This sentence might be better rephrased as "During pregnancy, thiamine is sent to the fetus via the placenta. Pregnant women have a greater requirement for the vitamin than other adults, especially during the third trimester."
• Please switch the order of the current second and third sentences, so that the sentences about thiamine in pregnancy is together.

Dietary recommendations

• I will alter the table to remove the third column at the end of the GA review.
• Please delete "As for safety".
• Please delete "Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes." as this is not specific to thiamine and not appear to be required for a reader to understand the data.
• I suggest that the lack of a UL from both the US National Academy of Medicine and the European Food Safety Authority is moved to form a separate, third paragraph.

Sources

• "and is important in maintaining plant health" – this does not appear to fit in this section. I suggest deleting it or moving it to the Biological Functions section.
• Please link "Indian government" to Government of India

Synthesis

• Please change "…and then combined to form…" to "…and are then combined to form…".
• I suggest changing "These are assembled by the action..." to "The ring is assembled by..."
• Please change "...pyrophosphate derivative of the phosphomethylpyrimidine..." to "...pyrophosphate derivative of phosphomethylpyrimidine..."
• I suggest changing "...the only riboswitch identified.." to "...the only known riboswitch found..."
• Please split the sentence "The ethoxy group was then converted..." into two, so that "ready for the final stage..." starts the second sentence as "In the final stage...".
• I suggest rephrasing "The 1936 laboratory-scale synthesis was developed by Merck & Co., allowing them to manufacture thiamine in Rahway in 1937." to "Merck & Co. adapted the 1936 laboratory-scale synthesis method, allowing them to begin large-scale manufacture of thiamine in Rahway in 1937." or similar.

Stopping here for now

I will aim to provide more feedback on the rest of the article on Saturday. Best wishes Mertbiol (talk) 21:04, 10 November 2022 (UTC)

Thanks, Mertbiol. I'll tackle these suggestions but probably not until Sunday, which will give you time to add anything more. While doing the first batch of changes, it occurred to me that the article says very little on how ThDP acts as a coenzyme. As an organic chemist, this seems quite important to me. It is covered, including poor diagrams, at Thiamine pyrophosphate#Reaction mechanisms. Should some of that be included here, especially the ability to form a ylide, which is crucial? I agree with you that the gallery of structures needs to be improved and I'll try out some colour schemes as you suggest. Mike Turnbull (talk) 11:13, 11 November 2022 (UTC)

Absorption, metabolism and excretion

• I think the distinction between pre- and post-consumption degradation is not very helpful, so I suggest renaming the current first subsection to "degradation".

Degradation prior to consumption

• The writing in this subsection doesn't really seem to flow very well – there are too many short sentences. The second half is unreferenced, so it may need a bit of a rethink. (It may be worth combining the two subsections.)
• I suggest rephrasing "Sulfites, which are added to foods usually as a preservative..." to "Sulfites, added to foods as a preservative..."
• I suggest deleting "in the structure" – anyone who understands an "attack at the methylene bridge" will know that this is a molecular reaction and "in the structure" does not help clarify for those that don't!
• I suggest deleting "Some thiaminases are produced by bacteria."
• Please link "acidotic conditions" to acidosis and "reduce" to redox.
• I suggest rephrasing "can have thiamine-antagonistic activities" to "can reduce the uptake of thiamine" or similar.
• Does the action degradation of thiamine by thiaminase in the rumen not take place after consumption?

After consumption

• I suggest renaming this subsection to "absorption and excretion" and then making this the first subsection of this section.
• I suggest rephrasing the first two sentences of this section to read "Some phenols found in plants, including caffeic acid, chlorogenic acid and tannic acid, degrade thiamine."
• I am not clear whether the discussion of phenols in plants relates to degradation of thiamine in the plant or to its degradation in the human body. (If the former, then this may not belong in the "after consumption" subsection.)
• I suggest rephrasing the first sentence of the current first paragraph to read "In the upper small intestine, thiamine phosphate esters released from food are hydrolyzed by alkaline phosphatase enzymes." or similar.
• I suggest switching the order of the third and fourth sentences of the second paragraph, so that discussion of active transport of thiamine is in one place.
• I suggest moving the paragraph beginning "The majority of thiamine in serum..." to a new subsection entitled "circulation in the blood and uptake by cells" or similar.
• Please change "coded by the genes SLC19A2 and SLC19A3" to "encoded by the genes SLC19A2 and SLC19A3".
• Please change "soluble thiamine transporter that is dependent on Na+" to " Na+-dependent transporter".

History

• Please delete "in 1910" from the first sentence.
• Please replace, "Prior to that..." with "Before its isolation..."
• Please delete "a disease" from the second sentence and the quotation marks around "beriberi".
• Navy should probably have a capital "N" in "Japanese navy".
• Please change "hypothesized" to "proposed" or "suggested".
• Please delete "substances" from "unknown substances at the time."
• Please change "so expensive a program" to "an expensive program" or "such an expensive program".
• Please split the final sentence of the second paragraph in two.
• Please link "Dutch Indies" to Dutch East Indies.
• Please link starch.
• I suggest rephrasing "He described the compound is not only anti beriberi factor but also essential nutrition to human in the paper" to "He described the compound as not only an anti-beriberi factor, but also as being essential to human nutrition."
• "However" should be preceded either by a full stop or a semi-colon.
• Please link "Oxford" to Oxford University.
• I suggest changing "introduced thiamine-deprived pigeons as a model for understanding how thiamine deficiency can lead to the pathological-physiological symptoms..." to "used pigeons to understand how thiamine deficiency results in the pathological-physiological symptoms..." or similar.
• I suggest changing "Indeed, feeding the pigeons upon polished rice leads to an easily recognizable behavior of head retraction, a condition called opisthotonos" to "Pigeons fed exclusively on polished rice developed opisthotonos, a condition characterized by head retraction."
• I am not sure how helpful it is to use the term "biological lesion" as it is not commonly used by research scientists today.
• Please correct the spelling of "Lohmann" - it has two "n"s!
• Please correct the spelling of "oxidative"
• I suggest rephrasing the final sentence of the final paragraph to read "In 1937, Lohmann and Schuster showed that the diphosphorylated thiamine derivative (thiamine diphosphate, ThDP) was a cofactor required for the oxidative decarboxylation of pyruvate."

Research

• This section is very short and doesn't seem to fit where it is. It might be better to move it to the "Synthesis" section, possibly as a new subsection called "Synthetic analogs" or similar.

Stopping here after the second read through

That's all for now. Best wishes Mertbiol (talk) 11:52, 12 November 2022 (UTC)

@Mertbiol All now done (except column removal from table), including updating the chemical diagrams and adding a bit about the ylide form. I think it would be helpful if you and David notMD could read through and reappraise. Mike Turnbull (talk) 13:39, 15 November 2022 (UTC)

Thanks @Mike Turnbull. I have removed the third column from the table, tweaked the layout of the images and given the text a light copyedit. I have also used thiamine pyrophosphate (TPP) in preference to thiamine diphosphate (ThDP) as this seems to be the preferred usage in the sources and on wikipedia. Perhaps both you and @David notMD: could take a quick look.

Assuming that all is well, I will read through for a final time tomorrow (Wednesday) evening. Best wishes Mertbiol (talk) 18:35, 15 November 2022 (UTC)

Yes, that ThDP versus TPP is a pain. I was inclined to use the former in this article only because it gives more internal consistency (ThMP, ThDP and ThTP) for the three derivatives. As you say, the pesky biochemists seem to prefer TPP, so let's go with that. Mike Turnbull (talk) 18:42, 15 November 2022 (UTC)

A new IP editor has recently attempted to fix one of my edits but seems to have ended up with duplicated content at Sources/Thiamin [sic] Antagonists and Absorption, metabolism and excretion / Degradation. I've left a message on their Talk Page asking them to engage with us here to reach a consensus on what the article should contain, as it currently seems incorrect to stay as-is. I moved the antagonist subsection to the degradation one following Mertbiol's suggestion here at Talk:Thiamine/GA1#Antagonists. Mike Turnbull (talk) 12:46, 16 November 2022 (UTC)

Hi @Mike Turnbull. Thanks for your message. I’ve had a look at the anonymous editor's changes. It seems to me that there are three separate issues with their edits:

• Use of "Thiamin" instead of "Thiamine" — The spelling has been discussed on the talk page and the clear consensus is for the latter to be used here on Wikipedia. It seems to me that this consensus reflects the overwhelming (but not universal) trend in the recent literature to use the "Thiamine" spelling.
• Use of the terms "anti-thiamine factors" and "thiamine antagonists" as synonyms. I have had a quick look at the recent literature and, from my reading, it is clear that these two terms do not refer to the same phenomenon. An antagonist is a molecule that competes with an agonist (in this case thiamine) for a receptor binding site whereas an "anti-thiamine factor" is responsible for the biochemical degradation of thiamine. My feeling is that the version of the article before the anonymous editor's changes reflected this position very clearly. I cannot see the justification for the current version which conflates the two terms.
• Organisation of the article. It would appear the anonymous editor would like to see the degradation of thiamine in food by "anti-thiamine factors" discussed in the "Sources" section. While there is merit in this layout, it does have the effect of splitting the degradation of thiamine between two sections (the "Sources" and the "Absorption, metabolism and excretion" section). On balance my feeling is that it is better to keep discussion of degradation in one place, again as in the version before the anonymous editor's changes.

It would be good if the anonymous editor could engage with this discussion and could explain the rationale for their changes more fully. Perhaps also @David notMD: could provide some input as the nominator. Clearly we are all anxious to avoid an edit war, which would derail the GA review process.
Best wishes Mertbiol (talk) 20:04, 16 November 2022 (UTC)

sorry to join the discussion so late. Your second point is a very good one, and I had not been aware of this distinction. ("A _thiamine_antagonist_ may be defined as a compound that can compete with thiamine, or thiamine precursors or derivatives, in enzyme reactions. "--E F Rogers)

My opinion is that the previous structure (anti-thiamine factors and thiamine antagonists being contained in the food sources section). This structure of the Thiamine page had been stable in this way for years, and my view is that there are good reason for this.

Final point, if we have a separate section for Thiamine Degradation, then one should at least link this section to the Thiamine food sources with a paragraph or sentence.

In my second edit I removed the redundant content, and did link the two sections together. To me this seemed to flow fairly well, and the structure was satisfactory. My final opinion is that all that remains to be done is to make changes to make the distinction between thiamine antagonists and anti-thiamine factors clear. 38.49.92.7 (talk) 22:16, 16 November 2022 (UTC)

sorry I didn't proofread before post; 2nd paragraph should instead start out with ""My opinion is that the previous structure (anti-thiamine factors and thiamine antagonists being contained in the food sources section) made for more informative and better flowing reading. 38.49.92.7 (talk) 22:19, 16 November 2022 (UTC)

Is it possible that Thiamine Antagonists are a broader category that includes both Agonists and ATF's.

Below is the paragraph from the original earlier November 9 version ( en.wikipedia.org/w/index.php?title=Thiamine&oldid=1120934845#Antagonists ) :

"Plant thiamine antagonists are heat-stable and occur as both the ortho- and para-hydroxyphenols. Some examples of these antagonists are caffeic acid, chlorogenic acid, and tannic acid. These compounds interact with the thiamine to oxidize the thiazole ring, thus rendering it unable to be absorbed. Two flavonoids, quercetin and rutin, have also been implicated as thiamine antagonists.

With an oxidized thiazole ring, would one consider the thiamine degraded? 38.49.92.7 (talk) 23:09, 16 November 2022 (UTC)

I think that earlier versions of the article have not used the word "antagonist" in its strict sense mentioned by Mertbiol. It is in that sense of "active site competitor" that I'm accustomed to using it. A recent article Wilson, Robert Beaumont (2020). "Pathophysiology, prevention, and treatment of beriberi after gastric surgery". Nutrition Reviews. 78 (12): 1015–1029. doi:10.1093/nutrit/nuaa004. PMC 7666909. PMID 32388553. is helpful in that it confirms that all the named chemicals caffeic acid, chlorogenic acid, tannic acid, quercetin and rutin are NOT antagonists in that sense but act to degrade the thiamine in various chemical ways. Indeed, the only true antagonist mentioned by Wilson is omeprazole, which is clearly not relevant for our article as it is a drug that most people would not be exposed to. The way forward, I think, is to use this review reference for all the statements we make about individual chemicals but to make it clear we mean "anti-thiamine", not "antagonist". I prefer to place whatever wording we agree in one subsection together at "Absorption, metabolism and excretion / degradation" because by if the thiamine is degraded by an anti-thiamine, then it can't be a source! Nevertheless, I don't mind if 38.49.92.7's logic feels it is better in the sources section. Maybe this is something where David notMD can help as he hadn't yet been heard on this issue? Mike Turnbull (talk) 11:54, 17 November 2022 (UTC)

Mertbiol, Michael D. Turnbull, 38.49.92.7 - My life complications have cleared. I will look at all the progress made toward achieving closure on the GA review, and see if I can make useful contributions. Deep appreciation to all the work done in my absence. David notMD (talk) 02:39, 17 November 2022 (UTC)

Hi All. I think the best thing to do now is for Mike Turnbull and @David notMD: to work together to propose a new wording for the "Sources" and "Absorption, metabolism and secretion" sections, using additional references. Once they've done that, perhaps 38.49.92.7 could suggest any amendments. Once consensus is reached, I can take a final look as the GA reviewer. Does this work for everyone? Best wishes Mertbiol (talk) 21:15, 17 November 2022 (UTC)

Works for me. I will be looking at it Friday morning. David notMD (talk) 04:37, 18 November 2022 (UTC)

I really don't follow this logic: "I prefer to place whatever wording we agree in one subsection together at "Absorption, metabolism and excretion / degradation" because by if the thiamine is degraded by an anti-thiamine, then it can't be a source! "

As long as there's a short paragraph within the Sources section that summarizes anti-thiamine factors (including caffeic acid, which is a very common one diets) then I don't mind if there is a section added in Metabolism and Degredation where there can be a subsection Degradation, where biochemists can elaborate and expand on the topic in great detail (substances that alter thiamine and the details). The summary paragraph in the sources section can then link to the more detailed discussion in the Degradation section. (I think I may have tried to finish it in this way in my final edit yesterday.)

I think possibly this might be the best of both worlds; a short summary paragraph on ATF's (and how it affects absorption and availability of dietary thiamine) in the food Sources and Nutrition part of the page, which the reader then can click through to follow up on much more detailed biochemistry and categories of anti thiamine factors a dedicated section on the topic elsewhere on the page. 38.49.92.7 (talk) 05:52, 18 November 2022 (UTC)

OK, let's see how David notMD gets on with a redraft (presumably here on the GA review page at first). The version in the live article is still as you had it. Mike Turnbull (talk) 12:25, 18 November 2022 (UTC)

First return to Thiamine after the start of the GA review

First, an appreciation to the editors who moved this forward in my absence. (My life had become very complicated for a longish while.) Second, my vitamin involvement history - I've been editing this article since 2016, intensively since January 2022, leading to my GA nomination in July 2022. Previously, I have raised ten vitamin articles to GA, leaving only Thiamine, Vitamin E and Vitamin D. Third, while I acknowledge that academic credentials and career experience do not perforce favor the opinion of any one editor over another, a long time ago I earned a doctorate in nutritional biochemistry, followed by a 40-year career in medical nutrition R&D and vetting scientific accuracy of health claims for functional foods, sports nutrition products and dietary supplements (now retired).

The issue at hand appears to be the subsection "Antagonists and Anti-thiamine factors" in the Sources section. Copied here: "The potential of thiamine in foods to be absorbed and utilized may be affected by antagonists contained naturally within the food, synthetic food additives, or thiamin degradation within the food by microorganisms prior and during food consumption. Plant thiamine antagonists are heat-stable and occur as both the ortho- and para-hydroxyphenols. Some examples of these antagonists are caffeic acid, chlorogenic acid, and tannic acid. These compounds interact with the thiamine to oxidize the thiazole ring, thus rendering it unable to be absorbed. Two flavonoids, quercetin and rutin, have also been implicated as thiamine antagonists." Ref is Combs (2008).

There is also an unreferenced sentence "Some plant phenols found in foods, including caffeic acid, chlorogenic acid, and tannic acid act as thiamin antagonists, or anti-thiamine factors." added to the Degradation subsection, with a Wikilink back to the previous content.

I do not have access to the Combs ref. I tried several PubMed approaches to the concept of thiamine antagonists and thiamine antivitamins. The most promising was "Thiamine and selected thiamine antivitamins - biological activity and methods of synthesis." (Tylicki 2018 PMID:29208764). It covered known chemical antagonists such as oxythiamine, but had no mention of any of the compounds in dispute here. As a different approach, I searched for thiamine and each of the proposed food or supplement compounds. I found little primary or secondary literature in support of the proposed content. For example, "Evidence against the reported antithiamine effect of caffeic and chlorogenic acids" (Horman, 1981 PMID:7327861) was negative. "Antithiamins of plant origin: their chemical nature and mode of action" (Hilker 1982 7044222) identified caffeic acid as an antagonist, based on high consumption of caffeic containing plants but only in animal models.

As the named acids are present in coffee and tea, I searched the scientific literature on thiamine x coffee or tea to little avail. This is important, because coffee and tea consumption is common, and includes a subset of people who consume LOTS of these beverages. In contrast, there are non-journal mentions of coffee and tea as thiamine antagonists. For example: "Causes of thiamine deficiency - Cornell University" at http://thiamine.dnr.cornell.edu/Thiamine_causes.html. The weakness is that websites like this refer back to the same weak and very old journal articles.

In conclusion, albeit unable to see Combs or what Combs referenced, in my opinon the scientific literature does not support naming caffeic, chlorogenic and tannic acids as thiamine antagonists, as the literature does not achieve WP:MEDRS. The disputed content sould be deleted. Even if some of the evidence is scientifically true (which I find very weak), the amounts consumed by humans from foods is not clinically relevant. David notMD (talk) 13:31, 19 November 2022 (UTC)

Hello, I have access to the Combs reference, albeit the fifth edition rather than the third edition as cited in the article. I can paraphrase the relevant section here if you'd like, but the quote you provided above has the same information with the exception that hemin apparently also binds thiamine, sequestering it.

However, what is most notable is that the book widely does not have any inline citations, so nothing can be easily traced to a source and verified. There are many footnotes adding context notes and sometimes citations, but the claims at debate here do not have them.

I recently noticed the thiamine good article review from the WikiProject Molecular Biology page, and wanted check what the process looked like since thiamine is a favourite enzyme cofactor of mine. Let me know if you want to discuss the reference (I'm not exactly clear with what I'm allowed to share under my university's permissions), and I'm a little interested in recreating the chemical diagrams to have a consistent style. Synpath (talk) 20:20, 22 November 2022 (UTC)

@Synpath All but two of the chemical diagrams (in the drugbox and of the ylide) were done by me using Biovia Draw then Inkscape to convert to .svg. I tried to make them as consistent as possible, for example in orientation. Was there something specific you think should be changed? Mike Turnbull (talk) 16:15, 23 November 2022 (UTC)

@Michael D. Turnbull Thanks for your work, especially the ThiC reaction diagram - seeing that got me into reading about the conversion after I skimmed the article. My main issue was that the diagrams should follow the ACS style per MOS:CDSG, and it would benefit my reading (at least on my browser/computer) as several of the diagrams not in that style are difficult to read since they are scaled down. There's also a nit picky issue with a bolded nitrogen in the thiazole synthase substrate. I'm not sure what Biova Draw is like to use, and I hope it's possible to import ACS style settings and resave the images without having to go to through the trouble of redrawing everything. If that's the case and you don't have time, I can pick that up. Synpath (talk) 18:16, 23 November 2022 (UTC)

@Synpath Interesting comments. I'm very well aware of MOS:CDSG (I wrote some of it!) and my defaults in Biovia Draw are indeed ACS style. The "problem" is that the guide is written with the assumption that, for example, text should be rendered as 10pt Arial. Everything else scales with that. In practice, using .svg files, the diagrams scale according to the space available on individual browsers (which can be influenced by using a specified pixel width for some images). If you scaled any of my diagrams to have exactly 10pt text, all the rest will be as the ACS guideline. However, that's NOT what happens in practice in articles. To see what I mean, click on a diagram and look at it full-size: it will fill your browser window, not just scale up to 10pt text. So I'm not sure what can or should be done. Well done for spotting the "bolded" nitrogen: I made a mistake there with a double nitrogen and I've fixed that. Mike Turnbull (talk) 18:39, 23 November 2022 (UTC)

For what its worth I was linking CDSG just to show I wasn't trying to impose a personal preference for ACS style, and I'm a little embarrassed to quote it to one of its authors. That being said I kinda don't understand the issue as I thought the ACS style prescribed a certain ratio between heteroatom letter size and bond length among other minutia, rather than point sizes of fonts (though it might define those ratios with a default point size). That ratio should be preserved in an SVG. I realize I'm making an assumption here, and I think I'll look into it this evening. The essence of my first point stands: some of the scaled down diagrams are hard to read. Bumping up the point size of the heteroatoms could be a solution. Synpath (talk) 20:00, 23 November 2022 (UTC)

Found the relevant point in the style guide, and it's basically "a benzene ring should be ~3.5 times as wide as a letter is tall" except using absolute measurements. For whatever reason the ratio isn't being preserved in a link in the chain to create the .svg (what even is a .emf file?), and I'm convinced if I were to figure that out by downloading those programs I could just redraw the diagrams instead. Not pinging as I don't think what I've written here is terribly useful. Synpath (talk) 06:24, 24 November 2022 (UTC)

I'll take this up on your Talk page, as it isn't really relevant to the GA review but is worth discussing as a general issue. Mike Turnbull (talk) 12:40, 24 November 2022 (UTC)

Quercetin and rutin - thiamine antagonists?

This statement "Two flavonoids, quercetin and rutin, are also considered to be thiamine antagonists." was found at Medigoo https://www.medigoo.com/articles/vitamin-b1-thiamine-deficiency/ without references (along with mention of coffee, tea and betal nut chewing). The concept is of interest because in addition to being compounds in foods, in some countries these compounds are sold as dietary supplements. Various searches did not find confirmation that quercetin or rutin act as thiamine antagonists. Mention of such should be deleted unless WP:MEDRS-compliant references can be provided. David notMD (talk) 14:16, 19 November 2022 (UTC)

Reviews?

@David notMD The article I mentioned above, doi:10.1093/nutrit/nuaa004, looked WP:MEDRS-compliant to me and has all the named compounds in its Table 3. I thought that the issue was the use of the word "antagonist" and where to place these statements. See all comments after "Stopping here after the second read through" above. Mike Turnbull (talk) 13:32, 20 November 2022 (UTC)

My concern continues to be that this and other "reviews" are citing inadequate primary research for caffeic chlorogenic and tannic acids, rutin and quercetin. (A referenced case can be made for foods that contain thiaminases, which can be inactivated with the heat of cooking.)

See: https://lpi.oregonstate.edu/mic/vitamins/thiamin This is the Linus Pauling Institute article on Thiamin. "Anti-thiamin factors (ATF): The presence of anti-thiamin factors (ATF) in foods contributes to the risk of thiamin deficiency. Certain plants contain ATF, which react with thiamin to form an oxidized, inactive product. Consuming large amounts of tea and coffee (including decaffeinated), as well as chewing tea leaves and betel nuts, have been associated with thiamin depletion in humans due to the presence of ATF (34, 35). ATF include mycotoxins (molds) and thiaminases that break down thiamin in food. Individuals who habitually eat certain raw fresh-water fish, raw shellfish, or ferns are at higher risk of thiamin deficiency because these foods contain thiaminase that normally is inactivated by heat in cooking (1, 6). In Nigeria, an acute, neurologic syndrome (seasonal ataxia) has been associated with thiamin deficiency precipitated by a thiaminase in African silkworms, a traditional, high-protein food for some Nigerians (36)." Ref 34 is Vimokesant (1975) PMID 803009, which presents evidence for fermented fish (thiaminase source) and betel nut chewing. Ref 35 is Ventura (2013) PNID 22436368, which presents a case study of one woman with high tea intake. REf 36 is Mishimune (2000) PMID 10827220), which presents the consequences of season consumption of silkworm larvae (thiaminase source).

The doi you mention is to Wilson RB (2020). It covers antithiamine factors on page 1020 and lists caffeic and tannic acids in coffee and tea, also quercetin and rutin, in Table 3. Thiaminases are described and referenced. The text's food refs are a WHO report and Vimokesant (1982) PMID 7044221. In the table, except for the WHO report, none of the referencs address the polyphenols or flavonoids. The WHO report (1999) https://apps.who.int/iris/bitstream/handle/10665/66139/WHO_NHD_99.13.pdf?sequence=1&isAllowed=y addresses anti-thiamine factors on pages 30-32. Again, thiaminases are presented. Vimokesant is cited as presenting evidence that tea drinking and tea leaf chewing [my bold] in Thailand was associated with thiamine deficiency. Hilker (1971) is cited in support of tannins, but that is an in vitro study, as are the evidences cited in Hilker (1982) PMID 7044222 for caffeic acid and other compounds. Table 15 of the WHO report - like in Wilson - lists polyphenols and flavonoids with no references. To summarize, Vimokesant 1975 and 1982 appear to present human evidence from Thailand for betel nut chewing and tea leaf chewing. Nowhere is there human evidence for caffeic acid, chlorogenic acid or the flavonoids, or for coffee or other polyphenol foods as having clinically relevant anti-thiamine activity. My opinion is that the two subsections I addressed in my previous comment be deleted and a subsection about food thiaminases be added. I am willing to write the latter if there is concensus on that.

Thus, after chasing the literature down the rabbit hole, my findings are that there are "reviews" based on old literature, mostly in vitro, and not strong enough to support the current text on anti-thiamine activity. David notMD (talk) 02:39, 21 November 2022 (UTC)

Thanks for doing the deep dive, David_notMD. I'm happy to have you amend the text in the live article as you propose. Then 38.49.92.7 can comment if they wish and that should allow Mertbiol to complete the GA review. Mike Turnbull (talk) 12:00, 21 November 2022 (UTC)

I will proceed to edit the article based on my assessment of the literature. Briefly, remove all content about polyphenols and flavonoids as antagonists, and chose one place to add referenced content about thiaminases. I state here that I do not have access to the Combs ref that is cited in support of the aforementioned putative antagonists, so if that ref in turn references credible clinical research, the situation can be reopened here at Talk. David notMD (talk) 12:06, 21 November 2022 (UTC)

Actually, thiaminases are already mentioned in the article, referenced, under Degradation and there is a thiaminase article. I will see what can be added that adds value to thiamine. David notMD (talk) 13:04, 21 November 2022 (UTC)

Hello, anon editor here, I've just created a handle, as I think this is looking like it may be a long term effort to improve and improve to a satisfactory state.

Only to mention thiaminases as antagonists of thiamine would be incredibly inaccurate. Also, it is not justified to make this change (including removing the long standing section of Antagonists within the Thiamin article) simply because the potency of the anti-thiamine effect in caffeic/chlorogenic and various polyphenols is much smaller (maybe an order of magnitude or almost two) than in those ATF's found in certain exotic foods (eg betel nuts and certain ferns). The latter can cause incredibly serious health issues (including beriberi and death) in certain populations. Instead, a statement should be made that effects vary greatly, and if possible to roughly quantify the degree these might impact a person's nutrition.

Low thiamine and B levels are not uncommon in the populations. This is probably especially the case for vegan and some vegetarian diets that are below or near the threshold given by officially recommended guidelines. David notMD, like many other males in my country, I drink a full pot of coffee over the day; can you be confident to predict that the ATF effects of the resulting caffeic and chlorogenic acids I'm consuming every day would not significantly impact my health if I were on a typical vegan diet (without specific supplements) skimming the threshold for suggested dietary B vitamin intake?

Lastly, if you cannot find population studies supporting measured clinical effects of various common ATF's, it may be because it is difficult (with so many other factors in subjects that might affect results), expensive, and very time consuming to conduct such studies. You can simply say that there is no conclusive evidence that consumption of thse ATFs in the general population results in clinical thiamine deficiency. PecanSequoiaForests (talk) 20:40, 25 November 2022 (UTC)

Once more into the breach

Notifying Mertbiol, Michael D. Turnbull and 38.49.92.7. To PecanSequoiaForests: I agree that it is possible that certain polyphenols and flavonoids inactivate thiamine. My reason for deleting the content is lack of evidence. As to "long-standing", the text and Combs ref was added on 28 April 2008, and remained unchanged until I recently removed it. When I reviewed and revised the article prior to nominating it for GA, I let it stand untouched, which was an error. While I do not have access to the Combs ref, in the extended discussion above, Synpath does, and states that information about these antagonists is in Combs WITHOUT INLINE CITATIONS. So that is one more 'review' type article that fails to present human evidence. In my own literature searches, nowhere in the literature did I find WP:MEDRS quality literature in support. Nor did I find useful human literature aside from the very old and limited lit be Vimokesant. I am not saying that these compounds may not interfere with thiamine, i.e., "antagonists" or whatever they may be called, only that published evidence is absent.

You (PSF) propose that the article contain a "...statement should be made that effects vary greatly, and if possible to roughly quantify the degree these might impact a person's nutrition." There is no evidence that any of the foods (coffee, tea, chocolate, etc.) mentioned in the 'reviews' listed above (Combs, Cornell, Linus Pauling Institute, Wilson, Medigoo) act as clinically relevant antagonists to any degree. All of that is speculation. My opinion is that speculation is not good enough to be in this article. Naming these compounds and foods that contain them as ATFs is a disservice to the readers. David notMD (talk) 07:02, 26 November 2022 (UTC)

Another 'review' example with no references: MedlinePlus at https://medlineplus.gov/druginfo/natural/965.html#FoodInteractions "Chemicals in coffee and tea called tannins can react with thiamine, converting it to a form that is difficult for the body to take in. This could lead to thiamine deficiency. Interestingly, thiamine deficiency has been found in a group of people in rural Thailand who drink large amounts of tea (>1 liter per day) or chew fermented tea leaves long-term. However, this effect hasn't been found in Western populations, despite regular tea use. Researchers think the interaction between coffee and tea and thiamine may not be important unless the diet is low in thiamine or vitamin C. Vitamin C seems to prevent the interaction between thiamine and the tannins in coffee and tea."

Non-human lit

Hilker (PMID 7044222) reviewed the in vitro and animal literature that appears to be the root reason for mention of these compounds as having antithiamine activity "ANTITHIAMINS OF PLANT ORIGIN: THEIR CHEMICAL NATURE AND MODE OF ACTION D. Hilker, J. Somogyi Published 1 March 1982 Chemistry, Medicine Annals of the New York Academy of Sciences. The existence of non-enzymatic thiamin inactivating factors in plant material was first observed by Weswig et al. in 1946, roughly ten years after the structure of this vitamin was established. This short note stated that rats fed bracken fern as 40% of the diet lost weight and developed symptoms suggestive of thiamin deficiency. The term “antithiamine activity” was used in describing this action and the possible relation to “fern poisoning” in cattle was discussed. Three years later, Evans and Evans2 confirmed these findings using rats fed a standard diet plus bracken leaves. Subsequently, Kundig and Somogyi analyzed a number of fruit and vegetables for antithiamin activity (ATA) and found highest activity in blueberries, red chicory, black currants, red beetroot, brussel sprouts, and red cabbage. The activity appeared to be associated with colored plants. Plant antithiamin activity was also studied by Japanese workers: Thai: and Indian investigators.6 The next investigations concerned the chemical nature of the antithiamin substances in plants. It was soon concluded that the activity was connected with phenolic compounds. Matsukawa and Kawakami determined the ATA of a number of phenols, quinones, catechol, and tannic acid: the optimal conditions for activity; as well as products of thiamin decomposition. They noted that (a) the ATA in plants was associated with phenol compounds having two OH groups, (b) the optimal pH was above 7.0 (c) the optimal temperature was above 5OoC, (d) the reaction required oxygen, (e) the reaction was inhibited by cysteine, and (f) thiochrome and thiamin disulfide appeared as reaction products of thiamin decomposition. After analyzing over 30 phenolic compounds for ATA, Somogyi and Bonicke postulated that the number and position of OH groups is of primary importance for antithiamin activity. Compounds having only one OH group had no activity, those with ortho OH groups had the highest activity, those with para OH groups had medium activity, and those having the OH in the meta position had no activity. Caffeic acid (3,4-dihydroxycinnamic acid) was isolated from fern’ and blueberries’” as one the the antithiamin factors in these plants. Sarkar and Chaudhuri” isolated and characterized an antithiamin factor from cotton seed as 3,5-dimethoxy salicylic acid. A more complex substance containing glucose and an ortho-hydroxy phenol group with CH3 and COOH radicals has been partially characterized from rice bran.” Williams in 1927 described experiments in which pigeons were fed rice mill by-products and developed..." From this article we have specific mention of caffeic acid and polyphenols for in vitro and animal research, but nothing subsequent in the lit for humans. David notMD (talk) 07:59, 26 November 2022 (UTC)

Final verdict

GA review (see here for what the criteria are, and here for what they are not)

1. It is reasonably well written.

   a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):

2. It is factually accurate and verifiable.

   a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):

3. It is broad in its coverage.

   a (major aspects): b (focused):

4. It follows the neutral point of view policy.

   Fair representation without bias:

5. It is stable.

   No edit wars, etc.:

6. It is illustrated by images and other media, where possible and appropriate.

   a (images are tagged and non-free content have non-free use rationales): b (appropriate use with suitable captions):

7. Overall:

   Pass/Fail:

This is a very interesting article. Congratulations to @David notMD: for the original nomination and to @Michael D. Turnbull: for doing much of the work to address the points raised during the review. Thank you also to @Synpath: and @PecanSequoiaForests: for their thoughtful input. I am happy now to promote the article. Congratulations to all. Best wishes Mertbiol (talk) 18:44, 5 December 2022 (UTC)