title: Prevalence and correlates of 25-hydroxyvitamin D deficiency in the Chronic Kidney Disease in Children (CKiD) cohort.
abstract: BACKGROUND
  Vitamin D plays an important role in the mineral and bone disorder seen in chronic kidney disease (CKD). Deficiency of 25-hydroxyvitamin D (25OHD) is highly prevalent in the adult CKD population.
  
  
  METHODS
  The prevalence and determinants of 25OHD deficiency (defined as a level <20 ng/ml) were examined longitudinally in 506 children in the CKiD cohort. Predictors of secondary hyperparathyroidism and the determinants of 1,25-dihydroxyvitamin D (1,25(OH)2D) levels were also evaluated.
  
  
  RESULTS
  Deficiency of 25OHD was observed in 28 % of the cohort at enrollment. Significant predictors of 25OHD deficiency were older age, non-white race, higher body mass index, assessment during winter, less often than daily milk intake, non-use of nutritional vitamin D supplement and proteinuria. Lower values of glomerular filtration rate (GFR), serum 25OHD, calcium and higher levels of FGF23 were significant determinants of secondary hyperparathyroidism. Lower GFR, low serum 25OHD, nephrotic-range proteinuria, and high FGF23 levels were significant determinants of serum 1,25(OH)2 D levels.
  
  
  CONCLUSIONS
  Deficiency of 25OHD is prevalent in children with CKD and is associated with potentially modifiable risk factors such as milk intake, nutritional vitamin D supplement use, and proteinuria. 25OHD deficiency is a risk factor for secondary hyperparathyroidism and decreased serum 1,25(OH)2D in children with CKD.
authors: Department of Pediatrics, Weill Cornell Medical College, New York, NY, USA. juk2013@med.cornell.edu.|, 505 East 70th Street, Box 176, New York, NY, 10021, USA. juk2013@med.cornell.edu.
authors: Juhi
authors: J
authors: Kumar
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors: Kelly
authors: K
authors: McDermott
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
authors: Alison G
authors: AG
authors: Abraham
authors: Outcomes after Critical Illness and Surgery Group, Johns Hopkins Hospital, Baltimore, MD, USA.
authors: Lisa Aronson
authors: LA
authors: Friedman
authors: Department of Pediatrics, Weill Cornell Medical College, New York, NY, USA.
authors: Valerie L
authors: VL
authors: Johnson
authors: Department of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.
authors: Frederick J
authors: FJ
authors: Kaskel
authors: Perelman School of Medicine at the University of Pennsylvania, Division of Nephrology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors: Susan L
authors: SL
authors: Furth
authors: Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.
authors: Bradley A
authors: BA
authors: Warady
authors: Department of Pediatrics, University of California, San Francisco, CA, USA.
authors: Anthony A
authors: AA
authors: Portale
authors: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA.
authors: Michal L
authors: ML
authors: Melamed
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000818:Animals; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D019587:Dietary Supplements; D005260:Female; D000089703:Fibroblast Growth Factor-23; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008892:Milk; D009656:North America / Q000453:epidemiology; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D018570:Risk Assessment; D012307:Risk Factors; D012621:Seasons; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy
chemical_list: D015415:Biomarkers; C000717427:FGF23 protein, human; C470125:PTH protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; D000089703:Fibroblast Growth Factor-23; C104450:25-hydroxyvitamin D
keywords: Chronic renal disease; Fibroblast growth factor 23; Hyperparathyroidism; Mineral metabolism; Pediatric