[Frontiers in vitamin D; basic research and clinical application. Vitamin D regulation of macrophage -dependent innate immunity].

Among various pleiotropic actions of vitamin D, its immunomodulatory role has been well recognized for more than 30 years. However, despite the presence of vitamin D receptors in immune cells including lymphocytes and monocytes/macrorphages, the impact of vitamin D system on immune regulation remained unclear. Recently, two key functions of vitamin D : induction of antimicrobial peptides and autophagy in cells of the monocyte/macrophage lineage, have been described, revealing a much clearer picture of the role of vitamin D as an immunomodulator, particularly in innate immunity against pathogens such as Mycobacterium tuberculosis. This review summarizes recent advances in research of vitamin D as a regulator of innate immunity, and clinical trials of vitamin D as a potential anti-infectious agent.