Long-term 1,25-dihydroxycholecalciferol treatment in renal failure.

1,25-Dihydroxycholecalciferol (1,25-DHCC) was administered to four patients on maintenance hemodialysis and to four patients with renal failure not requiring hemodialysis. Secondary hyperparathyroidism was found in both groups of patients. Before initiation of 1,25-DHCC treatment both groups had serum 1,25-DHCC levels below the normal range (33.1 +/- 15.3 pg/ml). During the treatment period, serum 1,25-DHCC concentrations were normalized. Parathormone concentration in serum decreased in both groups during the observation period. Serum calcium concentration was normalized in patients with renal failure and within the upper normal range in patients on maintenance hemodialysis. Bone biopsy and densitometry, of the radius showed a trend towards normalization of bone during the treatment period, while X-ray studies showed no clear effect of 1,25-DHCC treatment. This study shows that changes in bone mineralization can be reversed by normalization of 1,25-DHCC.