Folic Acid and B Vitamins Don’t Cut Cancer Risks

Colorectal adeomas are not affected by folic acid and vitamin B supplements

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) We just learned recently that long-term use of multivitamins helps lower the risk of cancers in men 50 years and older. A new study finds that a specific supplement doesn’t offer much help.

Supplements containing a combination of folic acid and vitamins B6 and B12 do not lower the risk of colorectal precancerous growths called adenomas in women who are at high risk for heart disease, according to a new Harvard study.

"Talk to your doctor about supplements."

About 1/3 of the people in the US have said they take supplements which contained folic acid, vitamin B6 and vitamin B12, which is found only in animal products.

The B vitamins have been of particular interest in the colorectal cancer world because lab and animal studies have shown that they fight against cancer formation.

And studies showed people with the highest intake of folic acid alone had roughly 30 percent reduced cancer risks.

Harvard Medical School Professor, Yiqing Song, MD, ScD, led the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS) - a tightly controlled trial involving 5,442 women health professionals who were at high risk for cardiovascular disease.

The women were followed from April 1998 to July 2005, and nearly 1,500 of the women received follow-up colorectal screens.

The study members were randomly assigned to receive either a placebo or a supplement that combined folic acid with vitamin B6 and vitamin B12.

Researchers found no significant difference in risks of precancerous colorectal cancer tumors among the two groups.

"We also found no statistically significant effect modifications by age; body mass index; smoking; alcohol intake; physical activity; menopausal status; PMH use; baseline plasma levels or intakes of folate, vitamins B6, and B12; current multivitamin use; and history of cancer, endoscopy, or adenoma."

Deborah Gordon, MD, told dailyRx News, “This study showing no benefit from supplementation with vitamins B6, B12, and folic acid will not deter me from carefully monitoring intake and adequacy of those vitamins. Reading the details carefully, I suspect that the people studied had problems to begin with, as they had high levels of homocysteine, a sign of deficiency of those B vitamins,” said Dr. Gordon, who is an Integrative Medicine Practitioner and Founder of DrDeborahMD.com

"The reasons for B vitamin deficiency are numerous, and involve both absorbing the vitamin and then using it effectively once it's in your body. That is why, in my office, I recommend these vitamins in more biologically useful forms. For folic acid, I suggest methylated folate or folinic acid. For B12 I recommend people find a form methylated sublingual vitamin B12, and finally, for B6, I suggest they take pyridoxal 5'-phosphate (P5P),” Dr. Gordon said.

This study, funded by published October 12 in the Journal of the National Cancer Institute was funded by the American Cancer Society and the National Institutes of Health

The pills and packaging used in the study were provided by Cognis Corporation and BASF Corporation. No conflicts of interest were reported.

Reviewed by: 
Review Date: 
October 17, 2012
Last Updated:
October 25, 2012