B-Vitamin Supplement Doesn't Lower Colorectal Cancer Risk
Combination of folic acid plus vitamins B6, B12 doesn't lower adenoma risk for high-risk women
MONDAY, Oct. 15 (HealthDay News) -- A combination of folic acid and vitamins B6 and B12 supplementation does not reduce the risk of colorectal adenoma among high-risk women, according to a study published online Oct. 12 in the Journal of the National Cancer Institute.
To examine the effect of combined B-vitamin treatment on the occurrence of colorectal adenoma, Yiqing Song, M.D., of Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues conducted a randomized, double-blind, placebo-controlled trial involving 5,442 women at high risk for cardiovascular disease who were randomized to receive a combination of folic acid (2.5 mg), vitamin B6 (50 mg), and vitamin B12 (1 mg) or placebo. Of these, 1,470 women were followed for as long as 9.2 years and underwent an endoscopy during follow up.
The researchers found that there was a similar risk of colorectal adenoma for those receiving combination treatment (24.3 percent) and those receiving placebo (24.0 percent). No statistically significant differences were observed on the basis of adenoma site, size, stage, or number. Alcohol intake, adenoma cancer history, or baseline plasma folic acid/vitamin B6, B12 levels did not affect the results.
"In conclusion, data from this study within a large, randomized, placebo-controlled trial indicate no apparent benefit or harm of combined folic acid, vitamin B6, and vitamin B12 supplementation on the risk of colorectal adenoma among women," the authors write. "Our findings do not support recommending B-vitamin supplementation for the prevention of colorectal adenomas."
Study supplements and placebos were provided by the chemical companies BASF and Cognis.