title: Hypovitaminosis D in adolescent females--an analytical cohort study in the United Arab Emirates.
abstract: BACKGROUND
  Despite living in a sunny country, hypovitaminosis D is common in women of reproductive age in Al Ain, United Arab Emirates (UAE).
  
  
  OBJECTIVE
  To establish the prevalence of hypovitaminosis D in adolescent female Emirati nationals and its risk factors.
  
  
  METHODS
  This was an analytical prospective cohort study of 350 female Emirati nationals aged 11-18 years attending public schools in Al Ain. Socio-economic status, diet and amount of sun exposure were evaluated by face-to-face interviews. Serum total 25 (OH) vitamin D (D2 + D3) levels were measured by electrochemiluminescence assay. The prevalence of hypovitaminosis D was calculated and the association with risk factors analysed.
  
  
  RESULTS
  Data were complete for 293 girls. Only one girl [prevalence 0.3%, 95% confidence interval (CI) 0.01-1.9] had vitamin D sufficiency (serum vitamin D levels >75 nmol/L). Three girls (1.0%, 95% CI 0.2-2.9) had vitamin D insufficiency (50-75 nmol/L), 58 (19.8%, 95% CI 15.0-25.5) were deficient (27.5-50 nmol/L) and 231 (78.8%, 95% CI 68.9-89.6) had severe deficiency (<27.5 nmol/L). Serum vitamin D levels declined between the ages of 11 and 13 years before progressively rising until the age of 18 years but without regaining the levels they were at the age of 11. There was no statistically significant difference between the vitamin D status groups in age, body mass index, accommodation type, family income, percentage of surface area unexposed to the sun when outdoors, consumption of oily fish or total vitamin D intake.
  
  
  CONCLUSIONS
  The finding of a high prevalence of hypovitaminosis D in adolescent females in UAE is of serious concern for their health and that of their infants during their reproductive lives. Adolescent girls with a similar social and cultural background currently living in less sunny, industrialised countries might also be at risk.
authors.forename: Hassib
authors.initials: H
authors.lastname: Narchi
authors.forename: Jose
authors.initials: J
authors.lastname: Kochiyil
authors.forename: Sania
authors.initials: S
authors.lastname: Al Hamad
authors.forename: Javed
authors.initials: J
authors.lastname: Yasin
authors.forename: Louis
authors.initials: L
authors.lastname: Laleye
authors.forename: Aisha
authors.initials: A
authors.lastname: Al Dhaheri
mesh_terms: D000293:Adolescent; D002648:Child; D002762:Cholecalciferol / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004872:Ergocalciferols / Q000097:blood; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D015995:Prevalence; D011446:Prospective Studies; D014479:United Arab Emirates / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D004872:Ergocalciferols; D002762:Cholecalciferol
keywords: Diet,; Epidemiology; Middle East,; Sunlight,; Vitamin D,