title: Vitamin D: seasonal and regional differences in preschool children in Great Britain.
abstract: OBJECTIVE
  To examine seasonality of 25-hydroxyvitamin D (25OH-D) levels in British preschool children and the effect of vitamin D supplementation on this.
  
  
  METHODS
  The National Diet and Nutrition Survey of children aged 1.5 4.5 y in Britain during 1992-3 measured dietary intakes and blood status indices, including those for vitamin D, during all four seasons. The present study addresses the seasonal dependence of the relation between vitamin D intake and status.
  
  
  METHODS
  100 randomly selected postcode sectors throughout Britain, whose locations were classified as (a) Scotland; (b) Northern England; (c) Central, Wales, South+SW; (d) London+SE.
  
  
  METHODS
  Of 1859 whose parents or guardians were interviewed, 1675 provided a weighed diet estimate, and blood vitamin D status (25OH-D) was measured in 756, with approximately equal numbers in each season.
  
  
  RESULTS
  Vitamin D status is highly dependent on season: moreover, the relation between vitamin D intake and status is also seasonally dependent, being strong in the winter and negligible in the summer. During the winter, those children who had relatively low 25OH-D concentrations generally were those not receiving vitamin D supplements. Vitamin D intakes and supplement use were lower in the north than in the south of Britain.
  
  
  CONCLUSIONS
  For British preschool children, dietary vitamin D is of much greater importance in the winter than in the summer. There is evidence of regional inequality, with lesser use of supplements in the north. Supplements are needed in the winter, to achieve satisfactory vitamin D status and minimise the risk of rickets and of poor bone health, especially in high-risk groups.
authors: Medical Research Council Human Nutrition Research, Cambridge, UK.
authors: P S
authors: PS
authors: Davies
authors: C J
authors: CJ
authors: Bates
authors: T J
authors: TJ
authors: Cole
authors: A
authors: A
authors: Prentice
authors: P C
authors: PC
authors: Clarke
mesh_terms: D002112:Calcifediol / Q000097:blood*; D002664:Child Nutritional Physiological Phenomena; D002675:Child, Preschool; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009752:Nutritional Status; D011897:Random Allocation; D012621:Seasons; D006113:United Kingdom; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: D014807:Vitamin D; D002112:Calcifediol