title: Vitamin D deficiency in children and adolescents with type 1 diabetes.
abstract: OBJECTIVE
  To investigate the frequency and effects of vitamin D deficiency in children with type 1 diabetes (T1D) in a region which is known to have a high rate of vitamin D deficiency among adolescents.
  
  
  METHODS
  In this prospective cross-sectional study, 120 children and adolescents with T1D (55 girls and 65 boys) aged 3-20 years were evaluated. Serum 25-hydroxyvitamin D [25(OH)D], parathormone (PTH), and alkaline phosphatase (ALP) levels were measured. Hemoglobin A1c levels and daily insulin requirement were also evaluated. Classification of vitamin D status was made according to the American Academy of Pediatrics (AAP)/LWEPS's recommendations. The patients were divided into 2 groups according to their vitamin D status and also according to the season of the year in which 25(OH)D sampling was done.
  
  
  RESULTS
  Serum 25(OH)D levels revealed vitamin D deficiency or insufficiency in 38% of the patients. Higher PTH levels were found in the patient group whose mean 25(OH)D level was < 20 ng/mL as compared to the group whose mean 25(OH)D level was > 20 ng/mL (p < 0.05). Only 11% of patients had secondary hyperparathyroidism. The 25(OH)D levels of patients whose serum samples were taken in summer and spring months were significantly different (p < 0.05). There were no significant correlations between 25(OH)D level and daily insulin dose.
  
  
  CONCLUSIONS
  Although we could not show a significant association between vitamin D deficiency and metabolic parameters, the frequency of vitamin D deficiency in T1D children is substantial. Vitamin D status should be assessed also in patients who do not have signs of rickets.
authors.affiliation: Kocaeli University, Medical Faculty, Department of Pediatrics, Kocaeli, Turkey.
authors.forename: Ajda
authors.initials: A
authors.lastname: Mutlu
authors.forename: Gül Yeşiltepe
authors.initials: GY
authors.lastname: Mutlu
authors.forename: Elif
authors.initials: E
authors.lastname: Özsu
authors.forename: Filiz Mine
authors.initials: FM
authors.lastname: Çizmecioğlu
authors.forename: Şükrü
authors.initials: Ş
authors.lastname: Hatun
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D011446:Prospective Studies; D012621:Seasons; D014421:Turkey / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000209:etiology*; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase