title: Metabolism of vitamin D3-3H in vitamin D-resistant rickets and familial hypophosphatemia.
abstract: The fate of an intravenous dose of tritiated vitamin D(3) was studied in seven normal subjects, four children with vitamin D-resistant rickets, and four adults with a familial history of vitamin D-resistant rickets and persistent hypophosphatemia. An abnormal metabolism of vitamin D in vitamin D-resistant rickets was defined and characterized by a decrease in the plasma fractional turnover rate, a marked increase in plasma water-soluble metabolites, and a relative decrease in the conversion of vitamin D to a polar, biologically active metabolite. Alterations in vitamin D metabolism in the adults with persistent hypophosphatemia were similar but less severe than those of affected children with vitamin D-resistant rickets. It is tentatively concluded that the abnormalities in vitamin D metabolism documented in patients with vitamin D-resistant rickets and familial hypophosphatemia may account for the observed osseous and biochemical changes.
mesh_terms: D000293:Adolescent; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D002118:Calcium / Q000097:blood; D002648:Child; D002762:Cholecalciferol / Q000032:analysis / Q000097:blood / Q000378:metabolism* / Q000652:urine; D002845:Chromatography; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D005243:Feces / Q000032:analysis; D005260:Female; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008297:Male; D010758:Phosphorus / Q000097:blood; D012279:Rickets / Q000097:blood / Q000378:metabolism* / Q000652:urine; D014316:Tritium
chemical_list: D014316:Tritium; D002762:Cholecalciferol; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium