title: Serum 25-hydroxyvitamin D levels and bone mineral density in 16-20 years-old girls: lack of association.
abstract: OBJECTIVE
  Hypovitaminosis D has been shown to be associated with low bone mineral density in middle-aged and elderly women. The aim of this study was to evaluate whether such an association might exist in adolescent and young adult girls, approaching peak bone mass.
  
  
  METHODS
  Cross-sectional study carried out in late winter.
  
  
  METHODS
  Reykjavik area at latitude 64 degrees N.
  
  
  METHODS
  Two-hundred and fifty-nine Icelandic Caucasian girls, aged 16, 18 and 20 years, randomly selected from the registry of Reykjavik.
  
  
  METHODS
  Bone mineral density in lumbar spine, hip, distal forearm and total skeleton was measured with dual-energy X-ray absorptiometry (DEXA) and compared with 25-hydroxyvitamin D levels [25 (OH)D] in serum, measured by radioimmunoassay. Calcium and vitamin-D intake were also assessed by a questionnaire.
  
  
  RESULTS
  18.5% of the girls were below 25 nmol L-1 in serum 25 (OH)D which has been recognized as the lower normal limit for adults. No significant association was found between 25 (OH)D levels and bone mineral density.
  
  
  CONCLUSIONS
  Normal calcium and phosphate concentrations in plasma and normal bone mineral density are maintained in adolescent and young adult girls at lower 25 (OH)D levels than published 'normal' levels for middle-aged and elderly.
authors.affiliation: Department of Internal Medicine, Reykjavik Hospital, Iceland.
authors.forename: J O
authors.initials: JO
authors.lastname: Kristinsson
authors.forename: O
authors.initials: O
authors.lastname: Valdimarsson
authors.forename: G
authors.initials: G
authors.lastname: Sigurdsson
authors.forename: L
authors.initials: L
authors.lastname: Franzson
authors.forename: I
authors.initials: I
authors.lastname: Olafsson
authors.forename: L
authors.initials: L
authors.lastname: Steingrimsdottir
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002118:Calcium / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage; D003430:Cross-Sectional Studies; D002149:Energy Intake; D005260:Female; D005838:Genotype; D006801:Humans; D008019:Life Style; D010710:Phosphates / Q000097:blood; D011110:Polymorphism, Genetic; D011863:Radioimmunoassay; D018167:Receptors, Calcitriol / Q000235:genetics; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D002136:Calcium, Dietary; D010710:Phosphates; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium