title: Vitamin D Deficiency in Children and Adolescents in Bağcılar, İstanbul.
abstract: OBJECTIVE
  This study aimed to evaluate the frequency of seasonal 25-hydroxyvitamin D [25(OH)D] deficiency and insufficiency in children and adolescents living in Bağcılar, district of İstanbul city.
  
  
  METHODS
  Serum vitamin D levels of 280 children aged 3-17 years old were measured at the end of winter and at the end of summer. Of the total group, vitamin D levels were re-measured in 198 subjects. Vitamin D deficiency was defined as a serum 25(OH)D level less than 15 ng/mL and insufficiency-as levels between 15 and 20 ng/mL. Patients whose vitamin D levels were less than 15 ng/mL at the end of winter were treated with 2000 units/day of vitamin D for 3 months.
  
  
  RESULTS
  In the "end of winter" samples, 25(OH)D deficiency was present in 80.36% of the subjects and insufficiency in 11.79%. In the "end of summer" samples, vitamin D deficiency was detected in 3.44% and insufficiency in 27.75%. Vitamin D levels in the "end of winter" samples were not significantly different between boys and girls, while "end of summer" levels were significantly lower in girls (p=0.015). Sunlight exposure was significantly higher in boys (p=0.011). The group with sufficient dairy product consumption had significantly higher vitamin D levels in both "end of summer" and "end of winter" samples. Limb pain was frequently reported in children with low vitamin D levels in the "end of winter" samples (p=0.001). Negative correlations were observed between vitamin D levels and season and also between vitamin D levels and age.
  
  
  CONCLUSIONS
  It is essential to provide supplemental vitamin D to children and adolescents to overcome the deficiency seen especially at the end of winter.
authors: Bağcılar Training and Research Hospital, Clinic of Pediatrics, İstanbul, Turkey Phone: +90 532 457 83 97 E-mail: drmeltemerol@yahoo.com.
authors: Meltem
authors: M
authors: Erol
authors: Özgül
authors: Ö
authors: Yiğit
authors: Suat Hayri
authors: SH
authors: Küçük
authors: Özlem
authors: Ö
authors: Bostan Gayret
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003611:Dairy Products; D004032:Diet; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D008297:Male; D012621:Seasons; D012737:Sex Factors; D012923:Social Class; D013472:Sunlight; D014421:Turkey / Q000453:epidemiology; D014505:Urban Population; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D006887:Hydroxycholecalciferols