Effects of 1,25-dihydroxyvitamin-D3 on renal function, mineral balance, and growth in children with severe chronic renal failure.

To confirm and extend previous observations of enhanced linear growth in children with chronic renal disease being treated with 1,25-dihydroxyvitamin-D3 and to characterize further the calcium, phosphorus, magnesium, and zinc disorders in renal failure, 11 children (mean age 8 +/- 5 years) with chronic renal insufficiency (glomerular filtration rate 18% +/- 13% of normal) were evaluated on the basis of their reciprocal serum creatinine concentrations, height-velocity curves, mineral balances, and radiologic findings. Reciprocal serum creatinine concentrations analyzed retrospectively and prospectively during 32 months of 1,25-dihydroxyvitamin-D3 therapy showed progression of renal failure at rates linearly identical with those before treatment, thus suggesting that the treatment did not accelerate the rate of deterioration of glomerular filtration rate in chronic anal insufficiency. Indeed, one patient manifested a lesser decline in renal function (P less than .05). The height velocity of six of the children (75%) less than 12 years of age improved markedly over that expected for chronologic and bone ages after one year of treatment with orally administered 1,25-dihydroxyvitamin-D3, 15 to 35 ng/kg/day. All other medications except vitamin D2 were continued at their pretreatment dosage levels throughout the study. Growth velocity was unimproved in two of three children older than 12 years at the initiation of 1,25-dihydroxyvitamin-D3 therapy. Mineral balance data showed significant retention of calcium, phosphorus, magnesium, and zinc (357 +/- 32 mg/sq m/day, 250 +/- 82 mg/sq m/day, 38 +/- 32 mg/sq m/day, and 1,157 +/- 283 microgram/sq m/day, respectively), after treatment for 12 months. In addition, serum calcium, alkaline phosphatase, and parathyroid hormone concentrations returned toward normal. Finally, healing of renal osteodystrophy was radiologically evident after six months of therapy.