Vitamin D was originally discovered as a factor that regulates calcium and bone metabolism. Recent advances in investigation have shown that vitamin D also functions as a regulator of cellular growth and differentiation in various tissues. Evidence has accumulated showing that the active form of vitamin D and its analogs suppress growth and stimulate the terminal differentiation of keratinocytes. Also, vitamin D stimulates the synthesis of melanin and release of interleukins. On the other hand, vitamin D has been used in the treatment of psoriasis, vitiligo and morfea for a long time. In this review, we summarize the fundamental features of vitamin D and the clinical application for psoriasis and other dermatological disorders.
