title: 25-Hydroxyvitamin D and glycemic control: A cross-sectional study of children and adolescents with type 1 diabetes.
abstract: OBJECTIVE
  The objective of this study was to describe the vitamin D status of children and adolescents with type 1 diabetes and to evaluate whether levels of 25-hydroxyvitamin D are significantly associated with HbA1c in this population.
  
  
  METHODS
  197 children and adolescents from a diabetes center in a children's hospital were recruited during regular follow up visit. Non-fasting blood samples were collected to measure 25-hydroxyvitamin D and blood glucose levels. HbA1c and other key variables were abstracted from patients' medical records.
  
  
  RESULTS
  Of the 197 children and adolescents, more than half were adolescents, males, and Caucasian. 23% were overweight, while 13% were obese. Mean HbA1c was 8.6±1.4% (70±15.3mmol/mol). 40.6% of patients had 25-hydroxyvitamin D levels ≤50nmol/L; 49.2% had 25-hydroxyvitamin D levels between 51 and 75nmol/L and 10.2% had 25-hydroxyvitamin D levels >75nmol/L. The bivariate relationship between 25-hydroxyvitamin D and HbA1c almost reached statistical significance (P=0.057), while no significance was established in the multivariate model.
  
  
  CONCLUSIONS
  To the best of our knowledge this is the first study that has been adequately-powered to examine the association between 25-hydroxyvitamin D and HbA1c in children and adolescents with T1DM. This study demonstrated the high prevalence of patients with low levels of 25-hydroxyvitamin D specifically in healthy weight and Caucasian children and adolescents with T1DM. These data suggest the need for monitoring of 25-hydroxyvitamin D in all youth with T1DM.
authors.affiliation: School of Nursing, University of Pennsylvania, PA, USA. Electronic address: al_sawah_sarah@lilly.com.
authors.forename: Sarah
authors.initials: S
authors.lastname: Al Sawah
authors.affiliation: School of Nursing, University of Pennsylvania, PA, USA.
authors.forename: Charlene W
authors.initials: CW
authors.lastname: Compher
authors.affiliation: School of Nursing, University of Pennsylvania, PA, USA.
authors.forename: Alexandra L
authors.initials: AL
authors.lastname: Hanlon
authors.affiliation: School of Nursing, University of Pennsylvania, PA, USA.
authors.forename: Terri H
authors.initials: TH
authors.lastname: Lipman
mesh_terms: D000293:Adolescent; D001786:Blood Glucose; D001835:Body Weight; D002648:Child; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy; D005260:Female; D006801:Humans; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D015995:Prevalence; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25-Hydroxyvitamin D; HbA1c; Type 1 diabetes