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.
DHT is a derivative of tachysterol. Tachysterol is a reaction side product in the light-dependent natural production of vitamin Ds.
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