PubMed ID: 27313313
Background and objectives: Vitamin D deficiency is endemic in children with CKD.We sought to investigate the association of genetic disposition, environmental factors, vitamin D supplementation, and renal function on vitamin D status in children with CKD. Design, setting, participants, & measurements Serum: 25-hydroxy-vitamin D, 1,25-dihydroxy-vitamin D, and 24,25-dihydroxy-vitamin D concentrations were measured cross-sectionally in 500 children from 12 European countries with CKD stages 3-5. All patients were participants of the Cardiovascular Comorbidity in Children with Chronic Kidney Disease Study, had CKD stage 3-5, and were age 6-18 years old. Patients were genotyped for single-nucleotide polymorphisms in the genes encoding 25-hydroxylase, vitamin D binding protein, 7-dehydrocholesterol reductase, and 24-hydroxylase. Associations of genetic status, season, local solar radiation, oral vitamin D supplementation, and disease-associated factors with vitamin D status were assessed. Results: Two thirds of patientswere vitamin D deficient (25-hydroxy-vitamin D