Folate, vitamin B-6, and B-12 intakes in relation to risk of stroke among men

Background and Purpose-Folate, vitamin B-6, and B-12 deficiency are related to elevated blood homocysteine level. However, the effects of intakes of these vitamins on risk of stroke are still uncertain. This study examines intakes of folate, vitamin B-6, and B-12 in relation to risk of ischemic and hemorrhagic stroke. Methods-We enrolled 43732 men, aged 40 to 75 years, who were free of cardiovascular diseases and diabetes at baseline. Participants were followed from 1986 to 2000. Dietary information was assessed every 4 years using a detailed and validated semiquantitative food frequency questionnaire. The main outcome measures were incident ischemic and hemorrhagic strokes. Results-A total of 725 incident strokes, including 455 ischemic, 125 hemorrhagic, and 145 unknown types of stroke, were documented during the 14-year follow-up. After adjustment for major lifestyle and dietary factors, intake of folate was associated with a significantly lower risk of ischemic but not hemorrhagic stroke. The multivariate relative risk of ischemic stroke was 0.71 (95% CI, 0.52 to 0.96; P for trend=0.05) for men in the highest quintile of intake compared with those who in the lowest quintile. Intake of vitamin B-12, but not B-6, was also inversely associated with risk of ischemic stroke. Conclusions-Our findings suggest that increased folate intake is associated with decreased risk of ischemic stroke in men.