title: Predictors and correlates of vitamin D status in children and adolescents with osteogenesis imperfecta.
abstract: BACKGROUND
  The prevalence of vitamin D deficiency and its consequences on bone in pediatric bone fragility disorders is not well characterized. In the present study, we evaluated determinants of vitamin D status in children and adolescents with osteogenesis imperfecta (OI) and assessed the relationship between 25-hydroxyvitamin D (25OH D) serum concentrations and lumbar spine areal bone mineral density (LS-aBMD).
  
  
  METHODS
  This retrospective cross-sectional study comprised 315 patients with a diagnosis of OI type I, III, or IV (aged 1.1-17.9 yr; 161 girls) who had not received bisphosphonate treatment at the time of 25OH D analysis. In 282 patients (90%), LS-aBMD measurements were available at the same time.
  
  
  RESULTS
  Serum concentrations of 25OH D ranged from 14 to 133 nmol/liter and were less than 50 nmol/liter in 86 patients (27%). Regression analysis revealed that age (P < 0.001), season (P < 0.001), and OI severity (P = 0.048), but not gender, were significant independent predictive factors of 25OH D levels. Serum 25OH D concentrations were negatively correlated with serum PTH levels (P = 0.003) and urinary cross-linked N-telopeptides of type I collagen to creatinine ratios (P = 0.005). Serum 25OH D levels were positively associated (P = 0.02) with LS-aBMD z-scores after accounting for OI severity, age, and gender.
  
  
  CONCLUSIONS
  Serum 25OH D levels are positively associated with LS-aBMD z-scores in children and adolescents with OI types I, III, and IV.
authors.affiliation: Shriners Hospital for Children and McGill University, Montréal, Québec, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Edouard
authors.forename: Francis H
authors.initials: FH
authors.lastname: Glorieux
authors.forename: Frank
authors.initials: F
authors.lastname: Rauch
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000293:Adolescent; D000375:Aging / Q000502:physiology; D000886:Anthropometry; D015519:Bone Density; D002112:Calcifediol / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008159:Lumbar Vertebrae; D008297:Male; D009752:Nutritional Status; D010013:Osteogenesis Imperfecta / Q000097:blood*; D012044:Regression Analysis; D012189:Retrospective Studies; D012621:Seasons; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood*; D055815:Young Adult
chemical_list: D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol