title: Serum Vitamin D Depends Less on Latitude Than on Skin Color and Dietary Intake During Early Winter in Northern Europe.
abstract: OBJECTIVE
  To evaluate if dietary vitamin D intake is adequate for sufficient vitamin D status during early winter in children living in Sweden, irrespective of latitude or skin color.
  
  
  METHODS
  As part of a prospective, comparative, 2-center intervention study in northern (63°N) and southern (55°N) Sweden, dietary intake, serum 25-hydroxyvitamin D (S-25(OH) D), associated laboratory variables, and sociodemographic data were studied in 5 to 7-year-old children with fair and dark skin in November and December.
  
  
  RESULTS
  Two hundred six children with fair/dark skin were included, 44/41 and 64/57 children in northern and southern Sweden, respectively. Dietary vitamin D intake was higher in northern than southern Sweden (P = 0.001), irrespective of skin color, partly due to higher consumption of fortified foods, but only met 50-70% of national recommendations (10 μg/day). S-25(OH) D was higher in northern than southern Sweden, in children with fair (67 vs 59 nmol/L; P < 0.05) and dark skin (56 vs 42 nmol/L; P < 0.001). S-25(OH) D was lower in dark- than fair-skinned children at both sites (P < 0.01), and below 50 nmol/L in 40 and 75% of dark-skinned children in northern and southern Sweden, respectively.
  
  
  CONCLUSIONS
  Insufficient vitamin D status was common during early winter in children living in Sweden, particularly in those with dark skin. Although, higher dietary vitamin D intake in northern than southern Sweden attenuated the effects of latitude, a northern country of living combined with darker skin and vitamin D intake below recommendations are important risk factors for vitamin D insufficiency.
authors.affiliation: *Faculty of Medicine, Department of Clinical Sciences, Pediatrics, Lund University, Malmö/Lund, Sweden †Faculty of Medicine Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
authors.forename: Pia Karlsland
authors.initials: PK
authors.lastname: Åkeson
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Lind
authors.forename: Olle
authors.initials: O
authors.lastname: Hernell
authors.forename: Sven-Arne
authors.initials: SA
authors.lastname: Silfverdal
authors.forename: Inger
authors.initials: I
authors.lastname: Öhlund
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D002112:Calcifediol / Q000097:blood; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D004032:Diet / Q000009:adverse effects; D000072001:Diet, Healthy; D019587:Dietary Supplements; D006801:Humans; D008137:Longitudinal Studies; D009752:Nutritional Status; D010349:Patient Compliance; D011446:Prospective Studies; D012307:Risk Factors; D012621:Seasons; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D012880:Skin Pigmentation; D012959:Socioeconomic Factors; D013472:Sunlight; D013548:Sweden / Q000453:epidemiology; D014807:Vitamin D / Q000378:metabolism / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*
chemical_list: D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol