Treatment of childhood renal osteodystrophy with calcitriol or ergocalciferol.

Quantitative bone histology, biochemistry and height velocities were studied in 18 children suffering from chronic renal failure. Eight received calcitriol, 7 ergocalciferol and 3, though alloted to a treatment group, failed to comply with therapy. A histochemical stain for aluminum showed heavy deposition at the calcification front in 3 patients; 2, in the calcitriol group had severe osteomalacia which worsened during treatment, and 1 in the ergocalciferol group had osteomalacia which did not improve. One had never undergone hemodialysis. Bone histology improved markedly in the remaining 12 patients, whichever vitamin D preparation was used; it was unchanged in 3 non-compliant children. Plasma calcium levels rose while parathyroid hormone and alkaline phosphatase levels fell following both treatments, and were unchanged in non-compliant children. Hypercalcemia occurred more frequently following calcitriol therapy (11 episodes) than following ergocalciferol therapy (3 episodes). Height velocities, studied in 11 children, increased in 5 (3 on ergocalciferol and 2 on calcitriol) and were unchanged in 6 (1 on ergocalciferol, 5 on calcitriol). Improved bone histology did not correlate with increase in height velocity. As ergocalciferol and calcitriol had similar therapeutic effects and as side-effects were more common with calcitriol, it is concluded that calcitriol provides no advantage over ergocalciferol in the treatment of renal bone disease in children.