title: Vitamin D deficiency at the Arctic Circle - a study in food-allergic adolescents and controls.
abstract: OBJECTIVE
  At the extremes of latitude, UVB intensity is insufficient for adequate vitamin D synthesis in winter. Fatty fish, vitamin D enriched milk, margarine and eggs are main dietary sources of vitamin D. Their elimination may increase the risk of vitamin D deficiency. The aim was to assess vitamin D status in food-allergic adolescents eliminating milk, egg and/or fish compared with adolescents on normal diets.
  
  
  METHODS
  In winter, vitamin D intake was assessed by a food frequency questionnaire in 20 food-allergic adolescents and 42 controls in the population-based Obstructive Lung Disease In Northern Sweden (OLIN) cohort studies. Vitamin D supplementation was queried. Serum 25-hydroxyvitamin D [S-25(OH)D] and S-parathormone (S-PTH) levels were determined.
  
  
  RESULTS
  Mean (SD) dietary vitamin D intake was 7.9 (3.6) μg/day in allergic adolescents and 7.8 (3.4) in controls (p > 0.05). Mean (SD) S-25(OH)D levels in supplement consumers were 44 (18) nmol/L compared with 35 (10) in non-consumers (p = 0.03). S-25(OH)D and S-PTH levels were similar in food-allergic adolescents and controls (p > 0.05). Eighty-two percentage had deficient S-25(OH)D levels <50 nmol/L, and none reached levels >75 nmol/L.
  
  
  CONCLUSIONS
  Vitamin D deficiency was as common in food-allergic adolescents as in controls although the vitamin D intake met national recommendations. Large-scale studies on the prevalence of vitamin D deficiency in this region are needed.
authors: Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
authors: Karin
authors: K
authors: Persson
authors: Inger
authors: I
authors: Öhlund
authors: Lisbeth
authors: L
authors: Nordström
authors: Anna
authors: A
authors: Winberg
authors: Eva
authors: E
authors: Rönmark
authors: Christina E
authors: CE
authors: West
mesh_terms: D000293:Adolescent; D001110:Arctic Regions / Q000453:epidemiology; D002648:Child; D021181:Egg Hypersensitivity / Q000453:epidemiology; D005260:Female; D005512:Food Hypersensitivity / Q000453:epidemiology*; D006801:Humans; D008297:Male; D016269:Milk Hypersensitivity / Q000453:epidemiology; D010281:Parathyroid Hormone / Q000097:blood; D017747:Seafood / Q000009:adverse effects; D013548:Sweden / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D