[Vitamin D and autoimmunity. First part: Fundamental aspects].

The effects of vitamin D on calcium homeostasis and bone metabolism are well known. In recent years, suboptimal vitamin D status has been recognized as a pandemic. Meanwhile, extra-skeletal effects of vitamin D are becoming better documented, particularly its effects on immunity. The authors present their actions on myeloid dendritic cells, T cells, B cells, as well as on the synthesis of antimicrobial peptides and autophagy, and the potential beneficial effects in autoimmune and inflammatory diseases.