title: Hypovitaminosis D in obese and overweight schoolchildren.
abstract: OBJECTIVE
  To determine the prevalence of vitamin D hypovitaminosis among obese and overweight schoolchildren.
  
  
  METHODS
  A cross-sectional population based sample.
  
  
  METHODS
  In a cross-sectional study, 301 students (177 girls and 124 boys) aged 11-19 years were selected by multistage stratified sampling design. Subjects were classified according to their body mass index as obese, overweight and normal. Serum 25-hydroxyvitamin D (25-OHD), intact parathyroid hormone (iPTH) and alkaline phosphatase (ALP) were measured in late winter months. Vitamin D deficiency was defined as a 25-OHD 20 ng/ml.
  
  
  RESULTS
  The prevalence of hypovitaminosis D was found as 65% in all students. Vitamin D deficiency was found in 12% and insufficiency in 53% of all students. Vitamin D deficiency in female students was about two times more common than in males. In obese and overweight schoolchildren with hypovitaminosis D, serum 25-OHD levels decreased as BMI increased. There were no correlations between serum 25-OHD and ALP and iPTH levels.
  
  
  CONCLUSIONS
  Vitamin D deficiency and insufficiency are common in obese and overweight schoolchildren, especially in girls. Obesity could be a risk factor in terms of hypovitaminosis D in adolescents. Vitamin D supplementation should be administered particularly to adolescent girls.
authors.affiliation: Division of Endocrinology and Diabetes, Department of Pediatrics, Kocaeli University, Faculty of Medicine, Kocaeli, Turkey. filizcizmeci@gmail.com
authors.forename: Filiz Mine
authors.initials: FM
authors.lastname: Çizmecioğlu
authors.forename: Nilay
authors.initials: N
authors.lastname: Etiler
authors.forename: Uzay
authors.initials: U
authors.lastname: Görmüş
authors.forename: Onur
authors.initials: O
authors.lastname: Hamzaoğlu
authors.forename: Şükrü
authors.initials: Ş
authors.lastname: Hatun
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications*; D050177:Overweight / Q000097:blood / Q000150:complications*; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D012307:Risk Factors; D014421:Turkey / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase