title: Impact of dietary and lifestyle on vitamin D in healthy student girls aged 11-15 years.
abstract: OBJECTIVE
  To study daily intake of calcium, phosphorus and vitamin D, to determine the biochemical findings of rickets and the effect of sunlight exposure and vitamin D supplementation in school girls with hypovitaminosis D.
  
  
  METHODS
  A cross-sectional study was conducted on school girls aged 11-15 years selected randomly from various areas of Tehran, Iran. Dietary information and amount of sunlight exposure were estimated by a 7 day recalling method using self-reported questionnaire. Hypovitaminosis D defined as low serum 25-hydroxyvitamin D concentration with two or more others abnormal biochemical findings. Girls with hypovitaminoses D were randomly divided into two groups. The faces and hands of girls in group 1 were exposed to sunlight for one hour per day for twenty days, while those in group 2 were administered vitamin D capsules, 50,000 IU per day for the same period.
  
  
  RESULTS
  four-hundred fourteen girls evaluated, mean daily calcium intake, sunlight exposure and vitamin D acquirement were 360 mg, 10 minutes and 119 IU, respectively. Mean serum 25-hydroxyvitamin D concentration was 30 ng/ml among all girls whereas in 15 (3.63%) of 414 girls was 7.8 ng/ml. Abnormal biochemical findings in these girls included hypocalcemia (n=4), hypophosphatemia (n=5), raised serum alkaline phosphatase (n=13), and parathyroid hormone (n=15). After intervention, mean serum 25-hydroxyvitamin D concentration in sunlight exposure (n=8) and vitamin D (n=7) supplementation increased to 14.4+/-4 ng/ml and 23+/-4 ng/ml respectively. There was a significant difference between the two groups (p<0.05).
  
  
  CONCLUSIONS
  Vitamin D deficiency developed in rapid growth period of girls without clear clinical rickets in sunny temperate climate city in Iran which vitamin D supplementation improved biochemical findings better than sunlight exposure.
authors.affiliation: Department of Pediatrics, Shaheed Beheshti University of Medical Sciences and Health Services, Tajrish sq., Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Dahifar
authors.forename: Ali
authors.initials: A
authors.lastname: Faraji
authors.forename: Aboulfazl
authors.initials: A
authors.lastname: Ghorbani
authors.forename: Saeid
authors.initials: S
authors.lastname: Yassobi
mesh_terms: D000293:Adolescent; D002136:Calcium, Dietary; D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008019:Life Style; D016226:Phosphorus, Dietary; D011446:Prospective Studies; D012279:Rickets / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood* / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000150:complications / Q000453:epidemiology* / Q000628:therapy
chemical_list: D002136:Calcium, Dietary; D016226:Phosphorus, Dietary; D014807:Vitamin D; C104450:25-hydroxyvitamin D