Talk:Folic acid

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I hope it's OK that I moved the folic acid "in food" to the top. I think it's a great article averall but I was having trouble finding about natural occurance and I think this is probably one of the main things readers are looking for, more basic than the other information. rusl

I hope the author of most of this does not mind my minor restructuring and additions. I felt that people looking it up in the sense of "pills I have been told to take" or "what's been added to my breakfast/bread etc" might benefit from some of this stuff near the top. Which is not in any way to demean the value of the biochemical detail, which is both interesting and important. Nevilley

I have done a brute-force import of most of the NIH factsheet. Wikification and merging is needed: I will do more later when I have time. -- Anon.

As the author of a lot of the biochemistry, all I can say is that the additions are terrific! This article was a couple sentences long when I first started touching on it, and this vitamin deserves a lot more consideration than that - David M



" a UL of 800 µg for pregnant and lactating (breast-feeding) women less than 18 years of age. "

    • the precision seems odd, why less than 18 years ? What about all the other who get prgnant after ??



Contents

[edit] Normal function in humans/organisms

[edit] Homocysteine

I'm not sure it's true that there is no proven link between homocysteine and IHD. I've got the MTHFR mutation and I am eating folic acid like sweeties. As are quite a lot of the medics I know. Maybe this is just 'cos I've got particularly concerned doctors, or maybe it's because I work in a place which produces some of the research, but from where I am sitting it looks clear. I am aware of the AHA's comments - I think we think (iyswim) they are wrong. However, (a) I am not up for an argument about this and (b) I'm not a doctor or a statistician and I couldn't progress this further without the help of one or both, and I am not sure the people I work with are quite ready for the Wikipedia concept yet!* :) So I think I will leave it for a bit and see how it develops. Nevilley

  • As in: how would you like to write something which anyone with internet access can change? Heheheh. Might almost be worth it just to watch them struggle with the disbelief!

I rewrote that section for one simple reason: people can be very simple minded when it comes to cause and effect in complex systems, and mistake a statistical association for a cause, or a special case for a general assertion. A classic example of this is an old 60 Minutes broadcast with Ed Bradley, where he tries to find something sinister in the presence of phenylalanine in steaks. Yea, duh. Steak has phenylalanine. Phenylketonurics had best be careful eating steaks. But that steak represents a nutritional and health problem for phenylketonurics doesn't make steak (in moderate portions, of course) a cause of serious health problems to the public at large.

Duh, me. Talk about trick memory. It wasn't steak Bradley was trying to persecute. It was a sweetener, the dipeptide with phenylalanine. But the same logic applies. Dwmyers

When you're dealing with the 1 carbon chemistry of methionine-homocysteine-folic acid, which is also affected by pyridoxamines and cobalamins, when the shutdown of these pathways affect a variety of physiological functions, including the synthesis of DNA, then I think it takes a higher bit of evidence than saying homocysteine did it. It *may* have done it. But something else in the maze of metabolic pathways may have done it as well. So, I want to see the study that proves homocysteine did it. But the chemistry of single carbon addition and sulfer containing amino acid chemistry cuts through almost everything in the field. Pruning the tree of possibilities to locate causes will be hard work.

So, if in contradistinction to the AHA stand, you have a study that demonstrates that homocysteine actually causes damage, as opposed to signaling damage, please post the reference. Finally, don't be afraid of the authority of your doctoral colleagues. If a respectfully worded question to one of them can't yield a respectful and thoughtful answer, then the problem is not you, its them. I'd use a more colorful phrase, but this place admits children too. - Dwmyers

I'm out of my depth here and will quite happily leave it to you. :) Nevilley

Regarding the section concerning folic acid and methotrexate in cancer chemotherapy - folic acid and folinic acid are different things. Folic acid has no role in methotrexate chemotherapy. Folinic acid (Leucovorin is calcium folinate) is used for methotrexate rescue in cancer chemo. I have amended the article to reflect this, as well as created an article on folinic acid. Techelf 14:05, 18 Sep 2004 (UTC)

Comment to the above (Techelf): I need to dig into my literature references, but I -think- that folic acid can also do rescue from methotrexate. I will check. 70.110.14.122 03:08, 13 January 2006 (UTC)CSari 1/12/2006

[edit] Selected food sources Section

I removed the final section on Selected food sources, as everything had already been mentioned above. It also refered to a table that existed in the NIH factsheet but was not reproduced here. — Asbestos | Talk 15:59, 4 Dec 2004 (UTC)

[edit] Edits to B12 deficiency and masking by folic acid

I have changed section 9, Caution about folic acid supplements, to indicate that there is little actual proof for masking of B12 deficiency by folic acid. I have also added the recommended allowance for B12, which is 2.4 microgram not 1000 microgram per day, and explained about malabsorption of B12 as it occurs in elderly subjects -- MKatan,14 June 2005

[edit] Folic acid and depression

It has been some time since I looked into this subject, but I still had a few articles bookmarked (see below). I think I am a bit out of my league as far as adding to this article is concerned, but I wanted to at least point this out in case someone else might be interested. To all who have contributed: this article is wonderful; thank you for such a well done addition to Wikipedia. - LeaMaimone 21:48, 15 Jun 2005 (UTC)


[edit] Folic acid and autism

This subsection should be added to controversies.

[edit] Cleanup: why "two" articles?

I'm wondering why there is a hard rule (i.e., ----) in the article. It appears as though the article was covering two different meanings of folic acid, though on closer inspection it really looks like two different versions about the same subject. Both parts really should be merged together. -- Gyrofrog (talk) 06:15, 6 October 2005 (UTC)

I just noticed the cleanup tag. I have raised the issue with WP:Chem, so hopefully this will be addressed soon. Walkerma 07:37, 10 December 2005 (UTC)

I haven't looked at this article very closely..yet on the surface, it served my needs and stands out to me to be a damn good article relative to many others that I have seen others laud and herald. As a wikipedia user, I am quite satisfied with this work.

I agree, this is an above-average article, so I've taken off the cleanup tag. --Squiddy | (squirt ink?) 12:40, 1 February 2006 (UTC)
Oops, I can't edit it without zapping the chinese/japanese interwiki links, cos my OS is so lame. Someone else rm the cleanup tag? --Squiddy | (squirt ink?) 12:41, 1 February 2006 (UTC)
Done. Csari 00:46, 6 February 2006 (UTC)

[edit] Biochemistry

Something seems to be amiss in the biochemistry section. I'm not seeing "methylidine tetrahydrofolate" in any references or online, except in duplicates of this wiki page. CHO-FH4 should be 5-formyl-tetrahydrofolate (or it could be 10-formyltetrahydrofolate, can't tell from the abbreviation used) If it is the 5-formyl, that's folinic acid.

Likewise, CH2=FH4 is unclear. Methylene-FH4 has a bridging -CH2- group between N5 and N10. Methenyl-FH4, the product of methenyltetrahydrofolate synthetase and substrate of SHMT (serine hydroxymethyl transferase) is generally abbreviated as CH+=FH4 (or =THF), reflecting (somewhat badly) a double bond between the one-carbon unit carried and N5, with a single bond to N10.

MOST of these folates (methyl, methenyl, methylene, but not 5-formyl) can act as one-carbon donors, so the simple scheme shown needs revision. I'm thinking a bunch of this should go off to the currently non-existent one carbon chemistry page with a link from this article.

Thoughts?

CSari 70.110.14.122 03:33, 13 January 2006 (UTC)


[edit] References

I've cleaned up the references - the number did not match the number of citations. Several duplications now addressed by the cite:ref system. However there is a citation of "Oldref_5a" that refered in the references to "Oldref_5", but this does not seem to exist.

The reordering of the references allows new citations to be added with ease, rather than previous confusing out-of-sequence numerics (see addition of info from clinical trials re folic acid and cardiovascular disease - the "proof-of-the-pudding" seems to be that it does not help).David Ruben Talk 05:20, 28 March 2006 (UTC)

[edit] Pteroylglutamic acid - a synonym?

American heritage dictionary says that pteroylglutamic acid is "folic acid". Should it be added as a #REDIRECT page?--CopperKettle 06:49, 1 September 2006 (UTC)

[edit] Dietary Fortification of Folic Acid

"Conversely, in the early 2000s, the US FDA prevented the import of Vegemite from Australia, citing, as the reason, that the folic acid levels are too high."

This claim has received recent media exposure, but lacks a citation. This seems odd given that the FDA is said to *cite* a specific reason for the import restriction. While www.fda.gov lists import refusals of Vegemite this year, citing causes including:

"It appears the manufacturer is not registered as a low acid canned food or acidified food manufacturer pursuant to 21 CFR 108.25(c)(1) or 108.35(c)(1)." 19 Jan 2006

"It appears that the manufacturer has not filed information on its scheduled process as required by 21 CFR 108.25(c)(2) or 108.35(c)(2)." 19 Jan 2006

"The article appears to be, or to bear or contain a color additive which is unsafe within the meaning of Section 721(a)." 27 Feb 2006

"It appears the food is fabricated from two or more ingredients and the label does not list the common or usual name of each ingredient." 27 Feb 2006

"The food is in package form and appears to not have a label containing an accurate statement of the quantity of the contents in terms of weight, measure or numerical count..." 27 Feb 2006

None of these causes appear consistent with the claim that import is restricted due to the levels of folic acid in the food. A citation to the contrary would strengthen the article.

I have removed it - as it has been removed from vegemite article until there's confirmation. The one news source I've seen gives no confirmation, just vague comments from unnamed "Australian expatriates in the US" - DavidWBrooks 15:21, 22 October 2006 (UTC)
"Kraft spokeswoman Joanna Scott said: 'The (US) Food and Drug Administration doesn't allow the import of Vegemite simply because the recipe does have the addition of folic acid.'" [1] --Robotech_Master 19:30, 22 October 2006 (UTC)

[edit] Confused and need help

http://www.news.com.au/story/0,23599,20623973-2,00.html
Can someone explain to me about this please? What caused America to ban this product? The artical mentions Folic acid. Thanks --58.6.1.178 10:10, 22 October 2006 (UTC)

[edit] Vegemite?

The FDA has apparently banned the importation of Vegemite into the US because it has folic acid added--and apparently folic acid can only be added to bread and cereal products, by US law. I came to this entry hoping I could find out more about why US law prohibits it from being added to other substances, but didn't find anything of that nature. Could someone perhaps write a section going into that? --Robotech_Master 19:18, 22 October 2006 (UTC)

Looking at the FDA regulations regarding the addition of folic acid to foods (21CFR172.345), there does not appear to be any language that could be construed to prohibit the addition of folic acid to foods other than breads and cereals. To the contrary, the cited regulation specifically sets rules for folate supplementation of infant formula, medical foods, supplements, and "meal-replacement products." I would be interested to see a citation to the contrary, but I think that the one news report that has generated this interest is incorrect regarding the cause for any (unconfirmed?) prohibitions on Vegemite importation. --Nllewellyn 18:06, 23 October 2006 (UTC)

[edit] Accuracy in measurements 1um is not 1mg

Dr. Myers and others;

Through out the http://en.wikipedia.org/wiki/Folic_acid regarding the dosages of Folic Acid are many references to 1000 ug. 1000 ug is equivalent to 1000 * 10 ^ -6 where 1000 mg is equivalent to 1000 * 10 ^ -3. Would you please review your data and make the appropriate corrections.

My Thanks,

LD Cooke 74.226.143.132 13:39, 14 December 2006 (UTC)

[edit] I am impressed

Today is 19 Jan 2007. I came here today looking for info on Folic Acid because of a news article on its effects. I found that Pol098 had already edited the article to refer to--not the news articles in the popular press--but the original article in Lancet, dated today. Wow! Well done!

Mcswell 13:43, 19 January 2007 (UTC)

[edit] Folic acid and methotrexate for Rheumatoid Arthritus

I have to take low doses of methotrexate for my RA (actually I have ankylosing spondyltus). My docotor recently found alarming levels of something in my blood... she said it looked like potential heart disease. Come to find out, I need to take folic acid. This is the second doctor that told me this (I moved and had to do all kinds of fun stuff, like getting a new doctor...). I have no idea how to make a wiki-standard appropriate addition to this for RA / AS. She said up to 800mg, btw -- if that means anything.

-- Nazadus 21:00, 5 Febuary 2007 (UTC)

[edit] Non-nutrition uses.

What does everyone think would be the best way to add in information not related to human nutrition? Add it as its own section? Specifically I was going to add information concerning the use of Folic acid in murine models of acute renal failure (ie. overdosing animals with FA to induce kidney failure) I want to separate it enough so that it is clear that this property does not create a hazard of taking too much FA but rather just an alternate, common use. Jvbishop 17:35, 6 March 2007 (UTC)

New section sounds sensible. --Michael C. Price talk 09:00, 8 March 2007 (UTC)
Ok, I put it in. I am a little worried about people deriving the conclusion from the addition that the levels of folic acid in food or vitamin supplements would be harmful in this way. Do you think my version is clear enough in this or should I add a comparison of dosage to the section...ie. equivalent human dosage would be 20grams or the amount found in x number of multivitamins. Jvbishop 14:33, 8 March 2007 (UTC)
You can try a comparison, but how to scale up is unclear: do you scale up according to metabolic rate, calorific throughput or by weight? --Michael C. Price talk 14:41, 8 March 2007 (UTC)
I'm not sure. I've seen studies done in rats that used the 250mg/kg dosage but I've not seen studies done with any other organism. Rat metabolism is a little different than mouse so I'm going with weight. I'm not thinking of suggesting a safe dose rather pointing out that to cause renal failure by folic acid overdose one would have to take far more than you can find in normal food or multivitamins. I may not even add anything. Jvbishop 15:00, 8 March 2007 (UTC)

[edit] error?

is this passage right? Because RNA and protein synthesis are not hindered, large red blood cells called megaloblasts are produced,--Ryan Wise 04:22, 14 August 2007 (UTC)

Probably correct. The production of thymine is hindered (required for DNA) but not uraacil (required for RNA). I presume the megablastic red blood cells do not have DNA.--Michael C. Price talk 05:58, 19 September 2007 (UTC)

[edit] Format Error

A table on this page is formatted incorrectly and I'm not sure how to correct it. Some editor should come by and fix it, this will prolly only take a sec. —Preceding unsigned comment added by 128.97.68.15 (talk) 16:54, 20 September 2007 (UTC)

[edit] "Experts claim" regarding spina bifida - is there any dispute?

A sentence currently reads: "Experts claim that this will decrease the number of babies with disabilities such as spina bifida." The "experts claim" implies there's dispute, while I took the connection to be a firmly established scientific fact. Is there any credible dispute? If not, I suggest changing wording to something like "Supplemental folic acid intake during pregnancy can significantly reduce the risk of infants being born with certain birth defects, particularly spina bifida." Statistics on reductions in countries that have required folic acid in varous foods could be added, but I think "significantly" conveys the point without getting too deep into side topics.

Literally thousands of journal articles could be cited; here's a fairly accessible one that happens to offer full text online, with a bibliography that contains several other free full-text citations:

Green, Nancy S. (2002.) "Folic Acid Supplementation and Prevention of Birth Defects." Journal of Nutrition, The American Society for Nutritional Sciences, 132:2356S-2360S, 2002. Retrieved on 2007-09-27.

-Agyle 19:08, 26 September 2007 (UTC)

You're right, there's absolutely no dispute about this. --Michael C. Price talk 19:52, 26 September 2007 (UTC)
I'm removed that sentence as part of a wider restructuring — there was some health stuff in the Folate in foods section, which I've moved elsewhere. Nunquam Dormio 07:00, 27 September 2007 (UTC)

[edit] folate

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Folate would be nice

Do you mean sth. like this? --NEUROtiker (talk) 07:48, 29 November 2007 (UTC)

[edit] Folate Levels too high

I'd like to see more about folate blood tests. One laboratory lists a normal folate blood level as greater than or equal to 3.5 ug/L. What is an elevated folate blood level and what could cause a too elevated level besides an overdose? ReasonableLogicalMan(Talk 19:24, 2 December 2007 (UTC)