title: High prevalence of vitamin D deficiency in children and adolescents with type 1 diabetes.
abstract: BACKGROUND
  Vitamin D is important for bone health. An inadequate supply of vitamin D to the body is associated with a higher fracture risk in the elderly. Young adults with type 1 diabetes are reported to have a lower peak bone mass than healthy individuals, which could possibly lead to an increased fracture risk in the future. The prevalence of vitamin D deficiency in healthy young people is high. Thus, optimal supply of vitamin D may be of particular importance for bone health in children with type 1 diabetes.
  
  
  METHODS
  In this prospective cross-sectional study we measured serum 25-hydroxy-vitamin D, iPTH, total and ionised calcium, phosphate, and alkaline phosphatase in 129 Swiss children and adolescents with type 1 diabetes.
  
  
  RESULTS
  Of the 129 subjects 78 (60.5%) were vitamin D deficient, defined as a 25-hydroxy-vitamin-D level below 50 nmol/L. During the winter this number rose to 84.1%. 25-hydroxy-vitamin-D levels showed marked seasonal fluctuations, whereas there was no correlation with diabetes control. Despite the high prevalence of vitamin D deficiency, we found a low prevalence of secondary hyperparathyroidism in vitamin D deficient diabetic children and adolescents.
  
  
  CONCLUSIONS
  Prevalence of vitamin D deficiency in diabetic children and adolescents is high. Therefore, screening for vitamin D deficiency and supplementation in children with low vitamin D levels may be considered.
authors.affiliation: Department of Paediatrics, Division of Endocrinology, Diabetology & Metabolism, Children's Hospital, University of Berne, 3010 Bern, Switzerland. marco.janner@insel.ch
authors.forename: Marco
authors.initials: M
authors.lastname: Janner
authors.forename: Pietro
authors.initials: P
authors.lastname: Ballinari
authors.forename: Primus E
authors.initials: PE
authors.lastname: Mullis
authors.forename: Christa E
authors.initials: CE
authors.lastname: Flück
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density / Q000502:physiology; D002118:Calcium / Q000097:blood; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000453:epidemiology*; D005260:Female; D005598:Fractures, Spontaneous / Q000097:blood / Q000453:epidemiology; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors; D013557:Switzerland; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D010281:Parathyroid Hormone; D010710:Phosphates; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase; D002118:Calcium