Vitamin D endocrine system and psoriasis vulgaris--review of the literature.

Vitamin D exerts its physiological functions on calcium and bone metabolism in humans through the active metabolite 1,25-dihydroxyvitamin D3(1,25(OH)2D3). The other spectrum of vitamin D activities includes important effects on cellular proliferation, differentiation and the immune system. These effects are mediated through the intracellularly located vitamin D receptor (VDR). VDR is a member of the steroid, estrogen and retinoid receptor gene family of proteins that mediate transcriptional activities of the respective ligands. The VDR complex binds in the nucleus to the vitamin D responsive element on the gene. Several polymorphisms of the vitamin D receptor (VDR) gene have been described including FokI in exon 2, BsmI and ApaI in intron 8 and TaqI in exon 9. Alterations in vitamin D-1,25 (OH)2D3 levels and polymorphisms of VDR gene have been shown to be associated with several malignant or autoimmune diseases such as sclerosis multiplex, breast cancer, diabetes mellitus, malignant melanoma, and psoriasis vulgaris. The effects of VDR gene polymorphisms including immunomodulation, stimulation of cellular differentiation and inhibition of proliferation make it a possible candidate for therapy of psoriasis as well as for the psoriasis gene modification. The objective of this article is to present the state-of-the-art in the VDR gene polymorphism research in psoriasis vulgaris.