Controlled trial of 1apha-hydroxycholecalciferol in chronic renal failure.

24 patients with chronic renal failure (glomerular filtration-rate (G.F.R.) 5-25 ml/min) participated in a double-blind placebo-controlled trial of the effects of 1 alpha-hydroxycholecalciferol (1alpha-H.C.C.) 1 mug daily for eleven weeks. This treatment induced significant increases in the intestinal absorption of calcium and in plasma-calcium which reached normal levels within two weeks. It also induced a significant reduction of the raised serum levels of parathyroid hormone. No significant changes were induced in plasma-phosphorus, plasma-alkaline-phosphatase, or in the degree of bone mineralisation as measured by the phosphorus/hydroxyproline ratio in bone. The bone mineral content in the forearm measured by photon absorptiometry decreased to the same extent in the 1alpha-H.C.C. groups and in the placebo group. The fall in G.F.R. over eleven weeks was 2-5 times greater in the 1alpha-H.C.C. group than in the placebo group, but this difference was not significant. It is concluded that 1alpha-H.C.C. treatment in chronic renal failure does not affect the progressive loss of calcium from bone despite normalisation of plasma-calcium.