has role calcitriol A hydroxycalciol that is calcidiol in which the pro-S hydrogen of calcidiol is replaced by a hydroxy group. It is the active form of vitamin D3, produced fom calciol via hydoxylation in the liver to form calcidiol, which is subsequently oxidised in the kidney to give calcitriol. hormone triol antineoplastic agent calcium channel agonist hydroxycalciol bone density conservation agent nutraceutical antipsoriatic immunomodulator D3 vitamins mouse metabolite human metabolite