title: High prevalence of vitamin D deficiency in school-age children in Tehran, 2008: a red alert.
abstract: OBJECTIVE
  To assess the vitamin D status of 9-12-year-old primary-school children in Tehran during autumn and winter 2007-2008.
  
  
  METHODS
  A descriptive cross-sectional study.
  
  
  METHODS
  Primary schools of Tehran city, Iran.
  
  
  METHODS
  A total of 1111 children aged 9-12 years (573 boys and 538 girls) from sixty primary schools were enrolled in the study. Weight, height, BMI and serum levels of Ca, P, Mg, 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone (iPTH), osteocalcin and bone-specific alkaline phosphatase of all the participants were assessed. Dietary Ca intake was also evaluated using a quantitative FFQ for a subsample of the study population (n 503). Vitamin D sufficiency was defined on the basis of serum levels of 25(OH)D as either ≥37 nmol/l (criterion 1) or ≥50 nmol/l (criterion 2).
  
  
  RESULTS
  Daily intake of Ca did not differ significantly between boys and girls (929·6 (sd 436·7) mg and 909·5 (sd 465·5) mg, respectively). However, on the basis of the first criterion, approximately 86 % of the children had vitamin D deficiency, with 38·3 % being severely deficient (25(OH)D < 12·5 nmol/l). According to the second criterion, prevalence of vitamin D deficiency rose to 91·7 %. Prevalence of vitamin D deficiency was higher in girls than in boys by either criterion. Serum levels of 25(OH)D inversely correlated with iPTH (r = -0·154, P < 0·001) and BMI (r = -0·092, P = 0·002) but directly correlated with duration of sun exposure (r = 0·115, P < 0·001).
  
  
  CONCLUSIONS
  The high prevalence of vitamin D deficiency among schoolchildren (especially among girls) warrants immediate interventions for proper nutritional support.
authors.affiliation: Laboratory of Nutrition Research, National Research Institute, Faculty of Nutritional Science and Food Technology, Shahid Beheshti University of Medical Sciences, PO Box 19395-4741, Tehran, Iran. t.neyestani@nnftri.ac.ir
authors.forename: Tirang R
authors.initials: TR
authors.lastname: Neyestani
authors.forename: Majid
authors.initials: M
authors.lastname: Hajifaraji
authors.forename: Nasrin
authors.initials: N
authors.lastname: Omidvar
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Eshraghian
authors.forename: Nastaran
authors.initials: N
authors.lastname: Shariatzadeh
authors.forename: Ali
authors.initials: A
authors.lastname: Kalayi
authors.forename: A'azam
authors.initials: A
authors.lastname: Gharavi
authors.forename: Niloufar
authors.initials: N
authors.lastname: Khalaji
authors.forename: Homa
authors.initials: H
authors.lastname: Haidari
authors.forename: Telma
authors.initials: T
authors.lastname: Zowghi
authors.forename: Bahareh
authors.initials: B
authors.lastname: Nikooyeh
mesh_terms: D015992:Body Mass Index; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D002136:Calcium, Dietary / Q000008:administration & dosage*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D015995:Prevalence; D012737:Sex Factors; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D