calcitriol

Calcitriol is the hormonally active form of vitamin D3 and is classified as a vitamin D analog. It is primarily used to treat and prevent low levels of calcium (hypocalcemia) and bone disease in patients with chronic kidney disease or parathyroid disorders. Calcitriol acts by binding to the vitamin D receptor (VDR), a nuclear receptor that regulates gene transcription. This interaction increases intestinal absorption of calcium and phosphate, enhances renal tubular reabsorption of calcium, stimulates release of calcium from bone via osteoblast-mediated activation of osteoclasts (through RANKL), and suppresses parathyroid hormone (PTH) synthesis by direct genomic effects in parathyroid cells[1][5][6]. Calcitriol also has immunomodulatory and anti-proliferative properties[3]. It is indicated for secondary hyperparathyroidism in chronic kidney disease patients not on dialysis or on dialysis; hypoparathyroidism; metabolic bone diseases associated with renal failure; and other conditions involving abnormal calcium metabolism[1][4][7].

Brand names

RocaltrolCalcijexVectical

Other names

1,25-dihydroxyvitamin D31,25(OH)2D3active vitamin D3