Nonclassical Effects of 1α,25-Dihydroxyvitamin D3 and Its Analogs

Abstract
The activated form of vitamin D3, 1α,25(OH)2D3, not only plays a central role in bone and calcium metabolism but has also potent antiproliferative and prodifferentiating effects. Moreover, the combined presence of 25(OH)D3-1α-hydroxylase as well as the vitamin D receptor in several tissues introduced the idea of a paracrine role for 1α,25(OH)2D3. By introducing chemical modifications into the flexible parent molecule 1α,25(OH)2D3, a whole generation of vitamin D analogs was created. Due to a clear dissociation of the antiproliferative and prodifferentiating effects from calcemic effects, these analogs can be used not only for the treatment of bone disorders but also for non-classical applications.