[Renal osteodystrophy in children. Therapy with 1,25-dihydroxy-cholechalciferol (author's transl)]. / Renale Osteodystrophie bei Kindern Therapieversuch mit 1,25-dihydroxy-cholecalciferol.

Growth arrest and renal osteodystrophy are major problems in renal insufficiency of children. The present report describes our experiences in managing renal osteodystrophy in 14 dialyzed children using 1,25-DHCC for 12 months. Values in plasma of Ca, P, Mg, alkaline phosphatase, iPTH, 25-OH-D, and 1,25-DHCC were determined regulary. Skeletal X-rays and analysis of iliac crest biopsies were obtained in each child. In treatment with 1,25-DHCC episodes of severe but reversible hypercalcemia occurred. Alkaline phosphatase and iPTH normalized completely. Radiographic examinations revealed marked improvement. Histological signs of fibro-osteoclasia and resorptive defects disappeared but there was no recovery of osteomalacia. A reduction of osteoblast population and of bone transformation was obvious. 1,25-DHCC failed to normalize growth in uremic children. In short, neither vitamin D nor 1,25-DHCC can guarantee complete recovery of renal osteodystrophy and growth arrest in uremic children.

Renal bone disorders in children: therapy with vitamin D3 or 1,25-dihydroxycholecalciferol.

Twelve children with chronic renal failure (CRF) and sixteen children receiving regular dialysis therapy (RDT) were treated with between 10,000 and 50,000 IU of vitamin D daily. This was associated with an increase in serum calcium levels and reduction in PTH levels. In the children with CRF, secondary hyperparathyroidism was improved with treatment but its development was not completely prevented nor was healing complete. In the patients receiving RDT, treatment with vitamin D improved the changes associated with secondary hyperparathyroidism in 50% of cases but these features sometimes reappeared despite continuing treatment. Hypercalcaemia or metastatic calcification was not seen. Subsequently, 1,25(OH)2D3 was administered to 14 children receiving RDT. This was associated with the return of serum calcium levels to normal, inhibition of PTH synthesis and an improvement in intestinal calcium absorption. Fibro-osteoclasia was cured and there was improvement in actual bone resorption. There was also improvement in osteoidosis in those children who showed disturbances of mineralisation. Calcification in the limbus area of the eyes may occur and hypercalcaemia was seen commonly. Treatment with 1,25(OH)2D3 should only be offered to children with severe renal bone disease. Neither vitamin D3 nor 1,25(OH)2D3 can guarantee complete recovery of osteodystrophy and of growth arrest in uraemic children.