By David Liu PHD

Sunday Aug 26, 2012 (foodconsumer.org) -- A new study in the journal Stroke suggests that low vitamin d intakes may increase risk of stroke.

The study led by Gotaro Kojima, MD of The John A. Hartford Foundation Center of Excellence in Geriatrics and colleagues showed that those whose vitamin v intakes were in the lowest quintile were 24 percent more likely to suffer all stroke and thromboembolic stroke during a 34 year follow-up, compared to those whose vitamin d intakes were in the highest quintile.

Vitamin D deficiency has been associated with increased risk of cardiovascular disease, particularly stroke, according to the researchers.

The current study was based on data from a prospective population-based cohort study of 8006 Japanese-American men aged 45 to 68 years in Hawaii who enrolled in the study in 1965 to 1968.  Intakes of vitamin D were estimated based on a 24-hour dietary recall.

During the follow-up, 960 subjects experienced stroke. The incidence of all stroke was 6.38 per 1000 person-years among those who had their vitamin D intake in the lowest quintile and 5.14 per 1000 person-years among those who had the highest intake.

After adjustment for age, total intake of calories, body mass index, blood pressure, diabetes mellitus status, pack-years smoking, physical activity index, serum cholesterol, and alcohol use, those whose vitamin D intakes were in the lowest quartile were at a 22 percent increased risk of incident stroke and 27 percent increased risk for thromboembolic stroke, compared with those having the highest intakes.

No significant associations was observed between dietary vitamin D intake and hemorrhagic stroke risk.

The researchers concluded "Low dietary vitamin D intake was an independent risk factor for 34-year incidence of all stroke and thromboembolic stroke in Japanese-American men. Additional research is needed on vitamin D supplementation to prevent stroke."