Vitamin B6 May Reduce Risk of Colon Cancer

BOSTON--Vitamin B6 supplementation appears to reduce the risk of colon cancer by 58 percent and of colorectal cancer by 44 percent, according to a new study from Harvard Medical School published in Journal of the National Cancer Institute (9, 97:684-692, 2005) (http://jncicancerspectrum.oupjournals.org).

Researchers analyzed the blood of nearly 33,000 women who provided blood specimens for the Nurses' Health Study in 1989, when they were 30 and 55 years, for blood levels of pyridoxal 5'-phosphate (PLP), the primary active form of vitamin B6 in blood. Researchers found the study group later developed 194 cases of colorectal cancer and 410 cases of colon polyps. To determine whether PLP had an effect on these conditions, participants' blood results were divided into four groups from lowest to highest blood levels of PLP; the highest quartile group showed a 44 percent lower risk of colorectal cancer and colorectal polyps and a 58 percent lower risk of colon cancer and colon polyps. The highest intake group had a median of 8.6 mg/d of PLP compared to 1.6 mg/d in the lowest intake group, near the RDA of vitamin B6 for adult men and women (2.0 mg/d and 1.6 mg/d, respectively).

The scientists/researchers concluded vitamin B6 supplementation may be associated with lower risk of colon cancer and colorectal cancer formation.