Vitamin D: It's not just for bones anymore

Abstract

It has become apparent that large segments of the population have vitamin D deficiency or insufficiency. This is of concern because vitamin D has biologic actions that influe nce immunity, inflammation, and oncogenesis in more than 30 tissues types with vitamin D receptors. Vitamin D deficiency has been associated with numerous disorders, including diabetes, rheumatoid arthritis, multiple sclerosis, and several typ es of cancer. Sufficient circulating levels of vitamin D are c ritical not only for healthy bones, but for many aspects of human health. The maintenance of adequate body stores of vitamin D depends on exposure to sunlight and dietary intake. Cutaneous synthesis of vitamin D and safe levels of dietary supplementation are discussed.