[Update on recent progress in vitamin D research. Vitamin D in the treatment of psoriasis.]

Active vitamin D and analogs exert immunomodulatory effects and potent effects on cellular differentiation and proliferation in the skin. In the last few decades, it has convincingly been shown that these analogs are effective and safe in the topical treatment of psoriasis, where they nowadays represent a standard therapy. However, the mechanism of vitamin D action in the treatment of psoriasis remains largely unknown. Here, we reviewed and discussed the recent findings of molecular action of vitamin D in psoriasis.