1,25 Dihydroxycholecalciferol Effects in Chronic Dialysis

Abstract

1,25 Dihydroxycholecalciferol [1,25(OH)2D3] was studied in a double-blind controlled fashion in patients [with renal osteodystrophy] on chronic dialysis. Serum Ca was unchanged in 16 patients on vitamin D3(D3) (400-1200 IU/day). In 15 patients on 1,25(OH)2D3 (0.5-1.5 .mu.g/day), serum Ca increased from 9.05 .+-. .15 to 10.25 .+-. .20 mg/dl (P < 0.001), returning to 9.37 .+-. .16 mg/dl (P < 0.001) in the post control period. Patients on D3 showed no reversible decrease in immunoreactive parathyroid hormone levels, but patients on 1,25(OH)2D3 did, from a control of 1077 .+-. 258 to 595 .+-. 213 .mu.l equivalents/ml (P < 0.01), and returned to 1165 .+-. 271 .mu.l equivalents/ml (P < 0.005). Nine of 12 patients on D3 who underwent serial iliac-crest biopsies showed histologic deterioration and 6 of 7 who received 1,25(OH)2D3 were improved or unchanged (P < 0.025). Bone mineral and Ca decreased in patients on D3 (P < 0.05) but not in those in 1,25(OH)2D3. Hypercalcemia occurred in 5 of 15 patients. 1,25(OH)2D3 has a calcemic effect in chronic dialysis patients, decreases levels of immunoreactive parathyroid hormone and is associated with histologic improvement in bone disease. Thus, 1,25(OH)2D3 is a valuable adjunct to the management of renal osteodystrophy but requires monitoring of serum Ca to avoid hypercalcemia.