Abstract
Vitamin D can only be made by sunlight exposure, and must undergo sequential metabolic activations to form its most active metabolite 1α,25(OH) 2D3 before exerting its hormonal actions in a variety of cells and tissues. 1α,25(OH) 2D3 regulates not only calcium and bone metabolism but also cell proliferation/differentiation, immune system and hormone secretion. 1α,25(OH) 2D3 binds to vitamin D receptor (VDR) and subsequent binding of the hormone-receptor complex along with Retinoid X receptor (RXR) to selected DNA sequences in chromosome induces gene expression of vitamin D-dependent proteins (a genomic action). Additionally, 1α,25(OH) 2D3 induces increases in intracellular calcium, transmembrane signaling, alterations in phospholipid metabolism and protein C kinase activity (a non-genomic action). In recent years, vitamin D research has made a remarkable progress.
This review article describes recent advances in basic and clinical vitamin D researches.
