Vitamin D: non-skeletal actions and rational use.

Recent years have witnessed a substantial increase in the number of seric determinations of vitamin D, in a worldwide basis. At Hospital das Clínicas of Faculdade de Medicina of Universidade de São Paulo that increase reached 700% over the last four years. Nevertheless there are many controversies on the literature about the role of vitamin D in conditions unrelated to the musculoskeletal system.