Low intake of vitamin B-6 is associated with increased risk of colorectal cancer in Japanese men.

We investigated the association of dietary intakes of folate, vitamin B-6, vitamin B-12, and methionine with the risk of colorectal cancer in a large prospective cohort study of middle-aged Japanese men and women. A total of 81,184 subjects (38,107 men and 43,077 women) who participated in the Japan Public Health Center-based Prospective Study were followed from 1995-1998 to the end of 2002, during which 526 cases of colorectal cancer (335 men, 191 women) were newly identified. Dietary intake of nutrients was calculated using a 138-item self-administered FFQ. We observed a significant inverse association between vitamin B-6 intake and colorectal cancer in men. Compared with the lowest quartile, the multivariate hazard ratio (95% [CI]) in the highest quartile of intake was 0.69 (0.48-0.98) (P(trend) = 0.03). Men who consumed 150 g/wk alcohol or more had twice the risk of colorectal cancer of those who drank less in the lowest quartile of vitamin B-6 intake, but risk due to alcohol intake was not higher in the highest quartile of vitamin B-6 intake. Vitamin B-6 intake and colorectal cancer were not associated in women. Folate and methionine intakes were not associated with colorectal cancer risk in men or women, but colorectal cancer risk tended to increase (P(trend) = 0.05) with increasing intake of vitamin B-12 in men. Our results support previous evidence that low vitamin B-6 intake is associated with an increased risk of colorectal cancer. In particular, a higher intake of vitamin B-6 appears beneficial in men with higher alcohol intake.