The B Vitamins and Folic Acid Do Not Prevent Cancer
A new study published in the Journal of the American Medical Association (JAMA) found that folic acid and other B Vitamin supplements do not prevent cancer. Dr. Shumin Zhang, associate professor of medicine at Brigham and Women’s Hospital and Harvard Medical School reviewed data on nearly 5,500 women over age 42 who had prior cardiac disease or at least three risk factors for heart disease.
They randomized the study participants and gave them daily supplements of 2.5 mg folic acid, 50mg Vitamin B6 and 1mg Vitamin B12 or a placebo.
After studying the women for 7.3 years they found no difference between the vitamin group vs. the control group in women who developed cancer. In the longest running trial of its kind, neither folic acid nor B vitamins prevented cancer in these women.
The findings for the B Vitamins versus placebo showed no difference in breast cancer, no difference in colorectal cancer, no difference in any cancer death and no reduction in all-cause mortality. The study also showed no harm from the Vitamin supplements.
Previous studies have suggested a protective role for these vitamins in cancer prevention but results have been varied. These findings are the latest in a number of studies that fail to show a benefit in vitamins preventing cancer. Last week, The National Cancer Institute stopped a trial of 35,000 men when they found Vitamin E and selenium didn’t prevent prostate cancer. Another study published in JAMA last year found people who take the supplements beta-carotene, Vitamin A and Vitamin E had increased premature death.
B6 and Vitamin B12 are water- soluble, essential vitamins. Approximately 1/3 of adults in the United States take multivitamin supplements containing these vitamins.
Other B vitamins include thiamin (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), folic acid (B9), cyanocobalamin (B12), pantothenic acid and biotin. We get B vitamins from leafy green vegetables, fruit, milk, fish, meat, rice, whole grain cereals and soy.