VITAMIN-D TO 1,25-DIHYDROXYCHOLECALCIFEROL - EVOLUTION OF A STEROID-HORMONE

An endocrine system has been described which is responsible for converting the seco-steroid, vitamin D, into its hormonally active form 1,25-dihydroxy vitamin D3. Since all vitamin D steroids have a conformationally active A-ring (unlike classical steroid hormones), an intriguing biochemical problem is to evaluate how the various receptors of the vitamin D-endocrine system accommodate to these unique ligands. © 1979.