Dihydrotachysterol (DHT)

Dihydrotachysterol (DHT) is a synthetic vitamin D analog activated in the liver that does not require renal hydroxylation like vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). DHT has a rapid onset of action (2 hours), a shorter half-life, and a greater effect on mineralization of bone salts than does vitamin D. The half synthetic Vitamin D analogue dihydrotachysterol (DHT) is widely used for hypocalcaemic hypoparathyroidism following surgical removal of parathyroids. Such treatment generally initiated by surgeons right after surgery has to be continued in clinical practice. Unfortunately, the required careful monitoring of calcium metabolism is often lacking and as demonstrated may lead to life-threatening conditions. In comparison to short acting vitamin-D derivates hypercalcaemic episodes with DHT appear to last longer and may therefore occur with higher incidence.