September 7, 2005Open Access
View Full PaperVitamin D Intake and Risk of Incident Hypertension
Key Result
Higher intake of vitamin D was not associated with a lower risk of incident hypertension (RR 0.98; 95% CI 0.93-1.04 for highest vs lowest quintile in NHS I).
Study Design
Type
Cohort (n=209,313)
Multicenter
Yes
Structured PICO
Does higher vitamin D intake prevent incident hypertension in participants of large prospective cohorts?
P
Population
209,313 participants from three large prospective cohorts followed for ≥8 years to assess the association between vitamin D intake and incident hypertension.
E
Exposure
Higher vitamin D intake (highest quintile, or ≥1600 IU/day, or ≥1000 IU/day)
C
Comparator
Lower vitamin D intake (lowest quintile, or <400 IU/day, or <200 IU/day)
O
Outcome
Incident hypertensionsurrogate
Higher vitamin D intake is not associated with a lower risk of developing incident hypertension.
Main Result
Relative Risk: 0.98 (95% CI 0.93–1.04)
Abstract
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 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.