Inner Circle Forums
Portions of the Undoctored Inner Circle Member Forum and its vast wealth of knowledge, are available only to our Members.
Becoming an Inner Circle Member will allow you to post topics, ask Dr. Davis questions, and view all replies.


The benefits and risks of folic acid supplementation from Science-Based Medicine


Member Forum >> Other Nutritional Supplements >> The benefits and risks of folic acid supplementation from Science-Based Medicine

Join Date: 7/29/2008
Posts Contributed: 5842
Total Likes: 146
Recommends Recd: 6
Ignores Issued: 2
Likes Recd: 0
Posted: 3/31/2011 8:23:03 AM
Edited: 6/3/2023 8:35:58 AM (1)

The benefits and risks of folic acid supplementation

Could a vitamin with proven benefits in one group cause harm to another? That’s the growing concern with folic acid, the vitamin that dramatically reduces the risk of neural tube birth defects such a spina bifida. Studies designed to explore the possible benefits of folic acid for heart disease, stroke and cancer are giving out some worrying signs: At best, folic acid is ineffective, and at worst it may be increasing the risks of some cancers. So what does this say about routine supplementation for the typical healthy individual, and its overall risk and benefit?

Folate (vitamin B9) is an essential nutrient found green, leafy vegetables, broccoli, peas, corn, oranges, grains, cereals, and meats. Folate has important roles in the synthesis of DNA, and consequently cell division. Significant folate deficiency can lead to macrocytic anemia. Folic acid, a synthetic form of folate, is used in multivitamins supplements because it is better absorbed.

Folic acid’s benefits in pregnancy are well documented. Supplementation before conception, and in the first few weeks of pregnancy, significantly and substantially lower the risk of several different birth defects, including neural tube defects (NTDs). The neural tube is the embryonic precursor to the brain and spinal column. NTDs include very serious defects like spinal bifida and anencephaly, birth without part of the brain.

 

The stakes are high, and because the neural tube forms so early in pregnancy (day 26 to 28), deficiencies must be corrected before a woman knows she is pregnant. This has led to public health strategies that mandate supplementation in food products: In both the United States and Canada, folic acid has been added to white flour since the late 1990’s, where it finds its way into baked goods like bread. Following food fortification, neural tube defects have subsequently dropped.

In addition to food fortification, women that could become pregnant are generally advised to take a multivitamin containing at least 0.4mg of folic acid daily. Women at high risk of NTDs may be advised to take higher doses. But as higher doses of folic acid can mask the symptoms of Vitamin B12 deficiency, higher doses warrant medical advice and supervision.

Even with fortification, it’s clear there are still opportunities to improve folic acid consumption in pregnancy. A Canadian population study showed that 20% of women of childbearing age failed to have appropriate folic acid levels in their blood. And while virtually no-one was dangerously deficient, over 40% had levels that would be considered high.

Beyond pregnancy

Observational trials have correlated a diet rich in fruits and vegetables with a lower risk of diseases like colorectal cancer. Based on this epidemiologic evidence, several randomized controlled trials were initiated investigating the effect of the B vitamins (including folic acid) on cancer risk. Folic acid held particular promise because of its proven effects preventing neural tube birth defects.

But the effects were not as expected.

The Warning Signals

That folic acid may interfere with cancer has been known since the 1940’s. The chemotherapy drug methotrexate is an antifolate agent that blocks the metabolism of folic acid, developed after it was noted that a diet deficient in folic acid helped patients with leukemia.

Studies of folic acid supplementation are raising flags about the potential risks of therapy, possibly as a result of excessive consumption. One of the most startling was a study that looked at folic acid supplementation in patients with colorectal adenomas, which are cancer precursors. Participants were randomized to folic acid 1mg or placebo for up to six years. While it was hypothesized that folic acid would provide a protective effect, the results were disappointing. Not only did folic acid have no effect on adenoma incidence (even in those with low folate status),  there was a significant increase in the risk of non-colorectal cancers (10.5% vs. 6.3%), due mainly to an excess of prostate cancers.

Futher worrying evidence emerged in 2009, when a Norwegian study of heart failure patients was published. Researchers randomized almost 7000 patients to folic acid and vitamin B12 versus other vitamins or placebo. The vitamins significantly raised the risks of both cancer and all-cause mortality, driven mainly by more cases of lung cancer. On balance, looking at heart disease, folic acid supplementation don’t seem to have any persuasive effects, either. In combination with other B-vitamins to lower homocysteine levels it hasn’t been shown to have meaningful effects on cardiovascular disease prevention, either.

The same worrying cancer signal has appeared with breast cancer in postmenopausal women, even while dietary folate seems to be beneficial. And in studies looking at prostate cancer, when folic acid is combined with other vitamins, the data are unclear.

So could fortification be causing harm? While correlations have been drawn between food fortification and population studies of colorectal cancer, causality hasn’t been established. Screening rates or other factors could be contributing. Still, the idea is troubling, even though the harms (if real) are slight compared to the demonstrable andsignificant benefits fortification has played  in reducing NTDs.  REST AT SITE


Moderator note 2023-06-03: basenote date revised as a side effect of getting this "UnKnown" TYP-vintage thread cross-assigned to a suitable Inner Circle forum.


Tags: folic acid,methylfolate

Join Date: 9/5/2010
Posts Contributed: 2397
Total Likes: 35
Recommends Recd: 2
Ignores Issued: 0
Likes Recd: 0

Dr Atkins warned against high amounts of folic acid since it elevates estrogen.


Tags:

Join Date: 2/6/2010
Posts Contributed: 285
Total Likes: 0
Recommends Recd: 0
Ignores Issued: 0
Likes Recd: 0


Reply Content Hidden!

Post replies longer than 250 characters are restricted to Full Access Members (make certain you are logged-in!).

Sign Up Today!


Tags:

Bob Niland
No Avatar
STAFF
Join Date: 7/7/2014
Posts Contributed: 21161
Total Likes: 3402
Recommends Recd: 10
Ignores Issued: 0
Likes Recd: 1
(uploadAI)
Posted: 10/23/2016 7:58:46 PM
Edited: 10/23/2016 8:48:17 PM (2)


Reply Content Hidden!

Post replies longer than 250 characters are restricted to Full Access Members (make certain you are logged-in!).

Sign Up Today!


Tags: Folate,folic acid,methylfolate

Join Date: 12/7/2009
Posts Contributed: 2394
Total Likes: 449
Recommends Recd: 6
Ignores Issued: 0
Likes Recd: 0
Posted: 10/24/2016 6:39:07 PM
Edited: 10/24/2016 6:39:23 PM (1)


Reply Content Hidden!

Post replies longer than 250 characters are restricted to Full Access Members (make certain you are logged-in!).

Sign Up Today!


Tags:

Join Date: 12/20/2007
Posts Contributed: 2769
Total Likes: 113
Recommends Recd: 16
Ignores Issued: 0
Likes Recd: 0


Reply Content Hidden!

Post replies longer than 250 characters are restricted to Full Access Members (make certain you are logged-in!).

Sign Up Today!


Tags:

Bob Niland
No Avatar
STAFF
Join Date: 7/7/2014
Posts Contributed: 21161
Total Likes: 3402
Recommends Recd: 10
Ignores Issued: 0
Likes Recd: 0
(uploadAI)


Reply Content Hidden!

Post replies longer than 250 characters are restricted to Full Access Members (make certain you are logged-in!).

Sign Up Today!


Tags: B12,B9,folic acid,methylfolate,vitamin b6


DISCLAIMER

The information contained within this Forum and website is of a general nature and intended purely as background reading for the participants taking part in Forum discussions and projects. Changes may occur in circumstances at any time that may affect the accuracy or completeness of the information presented within any section of the Forum and website. This Forum and Track Your Plaque, LLC have taken all reasonable care in producing and presenting the content contained herein, however, we do not accept responsibility for any loss, expense or liability that you may incur from using or relying on the information sourced from this website, its forums and/or blogs.

Third-party content and links

This Forum and Track Your Plaque, LLC accept no responsibility for the accuracy of third-party content or links, or your reliance on any information contained within any such content available through our site. The comments published on this Forum represent a wide range of views and interests of the participating individuals and organizations. Statements made during online discussions are the personal opinions of the commentators and do not necessarily reflect those of others participating on this Forum. Track Your Plaque, LLC at all times and at its absolute discretion, reserves the right to remove reasonably offensive comments in line with our Moderation Guidelines.