Vitamin D in human health

Abstract Vitamin D differs from other vitamins in that it is not a true vitamin but a prohormone obtained by endogenous synthesis from sun exposure on 7-dehydrocholesterol in the skin and from certain foods and dietary supplements. Its beneficial effects and physiological functions on musculoskeletal health are well understood. Mounting reports have recognized an association of vitamin D deficiency with a myriad of acute and chronic illnesses including autoimmune disorders, infectious diseases, cardiovascular diseases, common cancers, and neurological disorders, suggesting an important role of vitamin D in nonmusculoskeletal functions. Here, the role of vitamin D in skeletal health and present data on vitamin D in other nonmusculoskeletal diseases are reviewed.