Summary

Identification of the vitamin D receptor (VDR) and of enzymes of vitamin D metabolism in most cells and organs of the human body suggests that vitamin D may play a role in various extraskeletal diseases. In this review, we present a short overview of the role of vitamin D in oncology, immunology, infectiology, and neurology. Several experimental and epidemiological studies suggest that vitamin D may protect against cancer, immunological diseases (in particular autoimmune diseases), infections or neurologic disorders like strokes or neurodegenerative diseases. It should, however, be acknowledged that there are hardly any randomized placebo controlled trials on extraskeletal disease outcomes and therefore we can – at present – not draw final conclusions on these putative vitamin D effects. On the other hand, it must be underlined that the established effects of vitamin D on musculoskeletal health are considered to be sufficient to take actions to prevent and treat vitamin D deficiency.