Effects of 25 hydroxycholecalciferol on bone lesions of children with terminal renal failure

Abstract

Quantitative histology was performed on serial iliac crest biopsies obtained from 14 children with terminal renal failure. A long term study on the comparative effects of vitamin D2 and 25 hydroxycholecalciferol [25 (OH)D3], in 5 patients with severe lesions of osteomalacia and/or osteitis fibrosa, demonstrated the efficiency of 25 to 200 μg/day of 25 (OH)D3 and the lack of therapeutic action of 345 to 685 μg/day of vitamin D2. In 9 subjects with normal roentgenograms or minimal skeletal alterations, the first biopsy taken at the beginning of intermittent hemodialysis showed evidence of defective mineralization and/or lesions of resorption. 4 of these children were treated with 25 (OH)D3 (25 to 50 μg/day) and calcium supplementation orally (0.5 to 1.5 g/day); 5 children received calcium orally (0.5 to 0.75 g/day) alone. Aggravation of bone lesions during intermittent hemodialysis was observed in patients treated with calcium supplements alone. In subjects who were given 25 (OH) D3, mineralization improved and marrow fibrosis disappeared. However, as the 2 groups of patients were different in composition and in the manner in which they were treated, it is difficult to state whether the beneficial effects observed were solely attributable to 25 (OH)D3 administration. 25 (OH)D3 therapy induced severe intoxication in 2 patients. A rise in plasma calcium concentration to 11.0 to 11.5 mg/100 ml was observed in 2 other patients. It is concluded that: pharmacologic doses of 25 (OH)D3 are highly effective in healing bone lesions of children with terminal renal failure; such treatment requires strict clinical surveillance as 25 (OH) D3 intoxication may occur even in anephric patients.