Update on pharmacologically-relevant vitamin D analogues.

Pharmacologists have been interested in vitamin D since its metabolism was elucidated in the early 1970s. Despite the synthesis of thousands of vitamin D analogues in the hope of separating its calcemic and anti-proliferative properties, few molecules have reached the market for use in the treatment of clinical conditions from psoriasis to chronic kidney disease. This review discusses vitamin D drugs, recently developed or still under development, for use in various diseases, but in particular bone disease. In the process we explore the mechanisms postulated to explain the action of these vitamin D analogues including action through the vitamin D receptor, action through other receptors e.g. FAM57B2 and dual action on transcriptional processes.