Background: Although studies have linked vitamin D deficiency to an increased risk of cardiovascular disease (CVD), evidence regarding whether vitamin D intake from foods or supplements is prospectively associated with lower CVD risk in healthy humans is limited and inconclusive.
Objective: The objective was to comprehensively evaluate the associations between both dietary and supplemental vitamin D and CVD risk.
Design: In the Nurses' Health Study (1984-2006) and the Health Professionals Follow-Up Study (1986-2006)-consisting of 74,272 women and 44,592 men, respectively, who were free of CVD and cancer at baseline-we prospectively examined the association between vitamin D intake and incident CVD.
Results: Over a total of 2,280,324 person-years of follow-up, we identified 9886 incident cases of coronary heart disease and stroke. After multivariate adjustment for age and other CVD risk factors, a higher total vitamin D intake (from foods and supplements) was associated with a decreased risk of CVD in men but not in women; the relative risks (95% CIs) for a comparison of participants who met the Dietary Reference Intake of vitamin D (≥600 IU/d) with participants whose vitamin D intake was <100 IU/d were 0.84 (0.72, 0.97; P for trend = 0.009) for men and 1.02 (0.89, 1.17; P for trend = 0.12) for women.
Conclusions: These observations suggest that a higher intake of vitamin D is associated with a lower risk of CVD in men but not in women. Further research is needed to confirm these findings and to elucidate a biological basis for potential sex differences.