Vitamin D: a calciotropic hormone regulating calcium-induced keratinocyte differentiation.

Abstract

Most biologically active forms of vitamin D3 (1,25(OH)2D3) and its analogs have functions and therapeutic potential that extend beyond those of regulating bone mineralization and intestinal calcium transport. We attempt to provide the rationale for the effectiveness of 1,25(OH)2D3 and its analogs in dermatology. The recent literature on the mechanisms of action of 1,25(OH)2D3 were reviewed. 1,25(OH)2D3 affects keratinocyte differentiation partly through its regulation of epidermal responsiveness to calcium. Calcium and 1,25(OH)2D3 interact in transcription of the genes required for differentiation and in the stability of the mRNAs produced from such genes. An understanding of these mechanisms provides a rationale for treatment of various skin diseases with 1,25(OH)2D3 and its analogs and directs development of more effective therapy.