ORAL CALCIUM ABSORPTION IN PATIENTS WITH RENAL FAILURE TREATED BY CHRONIC HEMODIALYSIS

Oral calcium absorption, measured by a simplified isotopic method, has been assessed in patients undergoing chronic hemodialysis. By comparison with normal subjects, these patients had markedly impaired absorption irrespective of the duration of treatment or the number of dialyses. Responses to vitamin D administration were nil at 25,000 units but the pattern of absorption was successively increased into the low normal range by 50,000 and 100,000 units. It is concluded that dialysis successful by conventional criteria may fail to correct the defect in calcium absorption which accompanies renal failure. The resultant calcium deficiency may be important in the pathogenesis of renal osteodystrophy during dialysis. © 1969.