title: [Role of serum 25-hydroxyvitamin D in the diagnosis of vitamin D deficiency rickets].
abstract: OBJECTIVE
  To study the role of serum 25-hydroxyvitamin D in the early diagnosis of vitamin D deficiency rickets.
  
  
  METHODS
  Concentrations of serum 25(OH)D, calcium, phosphorus and alkaline phosphatase were measured in normal control (n=73), suspected rickets (n=45) and confirmed rickets groups (n=65). Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of serum 25(OH)D for rickets.
  
  
  RESULTS
  Serum 25(OH)D levels in the suspected and confirmed rickets groups were 83±30 and 72±31 nmol/L respectively, which was lower than in the normal control group (112±37 nmol/L) (P<0.01). There was no significant difference between the suspected and confirmed rickets groups (P>0.05). Vitamin D deficiency rates in the suspected and confirmed rickets groups were higher than in the control group (P<0.01). The ROC curve area of serum 25(OH)D for the diagnosis of rickets was 0.760 (95%CI 0.692-0.820, P<0.01), and the optimal operating point was 90.70 nmol/L (sensitivity 68.49%, specificity 72.73%). There was no significant difference in levels of calcium, phosphorus and alkaline phosphatase between the three groups (P>0.05).
  
  
  CONCLUSIONS
  Serum 25(OH)D levels in infants with suspected and confirmed rickets are significantly reduced and this may reflect vitamin D deficiency . Therefore, it may be useful to check serum 25(OH)D levels in screening for rickets.
authors.affiliation: Department of Health Care, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Wang
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Jin
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Wu
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Liu
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.forename: Na
authors.initials: N
authors.lastname: Li
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012372:ROC Curve; D012279:Rickets / Q000097:blood / Q000175:diagnosis*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D