<prompt> Increased calcium levels lead toIncreased 1,25 dihydroxycholecalciferolIncreased 24,25 dihydroxycholecalciferolDecreased calcitoninIncreased parathormone  <response>: 24,25-dihydroxycholecalciferol; a metabolite in calcium metabolism, formed in the kidney from 25-hydroxycholecalciferol by the activation of a 24-hydroxylase.Ref: Ganong;s review of medical physiology; 24th edition; page no:-379 