EFFECTS OF 1,25-DIHYDROXYCHOLECALCIFEROL ON CALCIUM ABSORPTION, MUSCLE WEAKNESS, AND BONE DISEASE IN CHRONIC RENAL FAILURE

Abstract

Small amounts (0.35-2.7 μg.) of 1,25 dihydroxycholecalciferol (1,25-D.H.C.C.), the hormonally active metabolite of vitamin D₃, were given to eleven patients with chronic renal failure for 4-150 days. 1,25-D.H.C.C. given for 4-8 days increased intestinal ⁴⁷Ca absorption without causing large changes in plasma calcium or phosphate, or in plasma or urine hydroxyproline measurements. 1,25-D.H.C.C. was given for a longer period (58 and 150 days) to two of the patients. In one, a 14-year-old girl, plasma alkaline phosphatase and non-protein bound hydroxyproline fell and there was healing of radiological rickets and secondary hyperparathyroidism; and in the other, a man of 58 years, there was striking improvement in muscle weakness. The resistance to treatment with vitamin D in chronic renal failure is probably related to impaired metabolic conversation to active derivatives, the most important of which may be 1,25–D.H.C.C. 1,25–D.H.C.C. seems capable of correcting some, if not all, of the disturbances in calcium metabolism in this disorder.