Research Area: Metabolic Disease Biological Activity: Calcitriol, also called 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin D3, is the hormonally active form of vitamin D with three hydroxyl groups (abbreviated 1,25-(OH)2D3 or simply 1,25(OH)2D). It increases the level of calcium (Ca2+) in the blood by increasing the uptake of calcium from the gut into the blood, decreasing the transfer of calcium from blood to the urine by the kidney, and increasing the release of calcium into the blood from bone. [1] |