Calcitriol

Calcitriol (INN), also called 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin D₃, is the hormonally active metabolite of vitamin D with three hydroxyl groups (abbreviated 1,25-(OH)₂D₃ or simply 1,25(OH)₂D), It was first identified by Michael F. Holick in work published in 1971. Calcitriol increases the level of calcium (Ca²⁺) in the blood by increasing the uptake of calcium from the gut into the blood, and possibly increasing the release of calcium into the blood from bone.

Nomenclature

Calcitriol usually refers specifically to 1,25-dihydroxycholecalciferol, but may also sometimes include 24,25-dihydroxycholecalciferol (when specified), the deactivated form of vitamin D.

Because cholecalciferol already has one hydroxyl group, only two are further specified in the nomenclature.

Pharmaceutical trade names

Calcitriol is marketed under various trade names including Rocaltrol (Roche), Calcijex (Abbott), Decostriol (Mibe, Jesalis), Biowoz (Solmarc) and Vectical (Galderma), Rolsical (Sun Pharma).