Circulating vitamin D metabolite concentrations in childhood renal diseases.
Vitamin D metabolites were measured in children, untreated with glucocorticoids, who had renal disease. Two groups were defined in relation to endogenous creatinine clearance values: those with impaired clearance , 0 to 48 ml/min per 1.73 m2; and those with unimpaired clearance, 75 to 150 ml/min per 1.73 m2. Serum 1.25(OH)2D was 16 +/- (SD) 12 pg/ml in impaired patients (N=24) and 48 +/- 16 pg/ml in unimpaired patients (N=18). The latter level is not different from healthy childhood controls (43 +/- 12 pg/ml; N=194). Serum samples of 25(OH)D2 and D3 were comparable in each group and not different from control values of 33.2 +/- 10.3 ng/ml. Serum 24,25(OH)2D was 0.6 +/- (SD) 0.14 ng/ml in patients with a clearance of less than 13 ml/min per 1.73 m2, 1.39 +/- 0.54 ng/ml in those with a clearance of 18 to 48 ml/min per 1.73 m2, and 152 +/- 0.91 ng/ml in patients without an impairment of clearance. Only patients with the lowest clearance had values different from control values of 1.70 +/- 0.57 ng/ml. In our study we suggest that a significant reduction in 24,25(OH)2D and 1,25(OH)2D are found at low clearance values in children with tubulointerstitial disease. Our study further suggests that a reduction in renal tubular mass is important in accounting for these changes in vitamin D metabolite values.
D015650:24,25-Dihydroxyvitamin D 3; D000293:Adolescent; D002112:Calcifediol; D002117:Calcitriol / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood; D004100:Dihydroxycholecalciferols / Q000097:blood; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D007223:Infant; D007674:Kidney Diseases / Q000097:blood*; D014807:Vitamin D / Q000097:blood*
D004100:Dihydroxycholecalciferols; D006887:Hydroxycholecalciferols; D014807:Vitamin D; D015650:24,25-Dihydroxyvitamin D 3; D003404:Creatinine; D002117:Calcitriol; D002112:Calcifediol