<prompt> Calcium absorption from gut is enhanced byParathyroid hormoneCalcitonin1,25 dihydroxy cholecalciferolAll  <response>: Calcitriol -1,25-dihydroxycholecalciferol; a form of vitamin D used as a calcium regulator in the management of hypocalcemia in conditions such as rickets, osteodystrophy, hypoparathyroidism, and complications of renal dialysis; administered orally or intravenously.Ref: Ganong;s review of medical physiology; 24th edition; page no:-377 