Vitamin D intake and risk of incident hypertension: results from three large prospective cohort studies.

Emerging evidence suggests an inverse relation between vitamin D and blood pressure. We examined the independent association between intake of vitamin D and the risk of incident hypertension among participants of 3 large and independent prospective cohorts: Nurses Health Study I (NHS I; n=77,436), NHS II (n=93,803), and Health Professionals' Follow-up Study (HPFS; n=38,074). Relative risks and 95% confidence intervals for incident hypertension were computed according to quintiles of vitamin D intake using Cox proportional hazards regression and adjusted for relevant covariates. Each cohort was followed for > or =8 years. Vitamin D intake was not associated with the risk of developing hypertension. The multivariable relative risk estimates for the highest compared with lowest quintile of intake were 0.98 (0.93 to 1.04) in NHS I, 1.13 (0.99 to 1.29) in NHS II, and 1.03 (0.93 to 1.15) in HPFS. When we compared participants who consumed > or =1600 to <400 IU per day and those who consumed > or =1000 to <200 IU per day, no association was found. We conclude that higher intake of vitamin D is not associated with a lower risk of incident hypertension.