How effective are B vitamins against cancer?

In a study of women who took vitamins B-6, B-9 and B-12 daily for slightly more than seven years, researchers found that the vitamins had neither a positive nor a negative affect on their subjects in regards to cancer when compared with a similar group who took placebos, according to an article on The study is a contrast to previous research that suggested that a lower risk of cancer was associated with taking those vitamins.

Some 5,442 female healthcare professionals with an average age of 63 participated in the study, which was published in the Journal of the American Medical Association. Of those women, 187 women from the vitamin group developed cancer, while 192 from the placebo group developed cancer.

"This study shows that supplementation with the combined B vitamins provided no beneficial effect and no harmful effect," said the study's leader, Dr. Shumin Zhang of Brigham and Women's Hospital and Harvard Medical school. "So in terms of cancer risk, this may not be an effective approach."

Women 65 and older who received daily B vitamins were found to be 25 percent less likely to develop any kind of cancer, and 38 percent less likely to develop breast cancer.

For more information on the study:
- here's the article from