Vitamin D and multiple health outcomes in the Harvard cohorts

The hypothesis that vitamin D is inversely associated with multiple health outcomes has been studied in the Harvard cohorts, including the Nurses' Health Study I (n=121,700 female nurses aged 37-64 at baseline in 1984), Nurses' Health Study II (n=116,671 female nurses aged 27-44 years at baseline in 1991), Health Professionals Follow-up Study (n=51,529 male health professionals aged 40-75 years at baseline in 1986), and Physicians' Health Study (n=22 071 male physicians aged 40-84 years at baseline in 1982). These studies assessed vitamin D through circulating 25-hydroxyvitamin D, dietary and supplemental intake, predicted 25-hydroxyvitamin D, and vitamin D receptor polymorphisms. This review summarizes studies of vitamin D and various endpoints considered in these cohorts, including risk of cardiovascular disease, hypertension, elevated plasma C-peptide, various cancers, bone fractures, and multiple sclerosis. Based on the multiple observed benefits of vitamin D, this article postulates recommendations for vitamin D intake in the US population for reduced incidence of multiple health outcomes.