Effect of dihydroxylated metabolites of vitamin D3 on calcium absorption in uraemic man.
1. Peak 47Ca absorption and 7 day 47Ca retention were measured by a whole-body radioactivity counting technique in 10 haemodialysis patients before and after treatment with 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] and 24,25-dihydroxycholecalciferol [24,25-(OH)2D3]. 2. Before treatment all patients had low peak 47Ca absorption and 7 day 47Ca retention. 3. After treatment with 1,25-(OH)2D3 (0 . 25-l microgram/day for 4-12 months) peak 47Ca absorption and 7 day 47Ca retention returned to normal. 4. After treatment with 24,25-(OH)2D3 (2 microgram/day for 4-12 months) peak 47Ca absorption and 7 day 47Ca retention remained at pretreatment levels. 5. It is concluded that physiological doses of 24,25-(OH)2D3 have no effect on calcium absorption or retention in uraemic man.
D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol / Q000627:therapeutic use*; D002118:Calcium / Q000378:metabolism*; D004100:Dihydroxycholecalciferols / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000627:therapeutic use*; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D006435:Renal Dialysis; D014511:Uremia / Q000188:drug therapy / Q000378:metabolism*
D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D015650:24,25-Dihydroxyvitamin D 3; D002117:Calcitriol; D002118:Calcium