title: [Vitamin D nutrition in Chilean pre-school children living in extreme latitudes].
abstract: BACKGROUND
  Sunlight exposure is the main factor for adequate vitamin D (VitD) nutrition; in extreme latitudes there is an increased risk for its deficiency.
  
  
  OBJECTIVE
  To study VitD nutritional status in pre-school children living in austral latitudes of Chile.
  
  
  METHODS
  A blood sample was obtained from 60 pre-school healthy children (aged 2 to 5 years, 24 males), attending to public day-care centers in Coyhaique (45° 35' S), during March (time 1) and September (time 2). 250 HD, parathyroid hormone (PTH), calcium, phosphate and alkaline phosphatases (PA) were measured. Information about weather conditions during three months prior to the sample withdrawal was gathered.
  
  
  RESULTS
  Forty nine percent of children had a normal weight and 11% were overweight. Vive children with unreliable 250 HD levels were excluded from analysis. At time 1, 250 HD levels were 21.6 ± 14.5 ngl mh (7.9-71.1). Sixty four percent of children had valúes < 20 ng/mL (deficiency). At time 2, the figures were 21.5 ± 13.2 ng/mL (9.4-68.5) and 67.3% of children were deficient. PTH, serum calcium, phosphate and PA were normal. Prior to time 1, the UVradiation Índex (UVI) was high to extreme (91.3%), with 3.3 and 73% of sunny and cloudy days, respectively. Mean minimal and maximal temperatures were 7 and 17.3°C respectively. Prior to time 2 the IUVwas low in 100%) of days; with 15.2 and 60.9 of sunny and cloudy days, respectively. Mean minimal and maximal temperatures were 0.3 and 6.7°C respectively. No association of 250 HD with the other metabolicparameters was found.
  
  
  CONCLUSIONS
  Chilean pre-school children living in austral latitudes have a high rate of vitamin D deficiency, throughout the year, with no association with PTH, calcium, phosphate or PA. Further research is required to study vitamin D deficiency in other latitudes and magnitude of sunlight exposure.
authors.affiliation: Departamento de Pediatría Campus Centro, Facultad de Medicina, Universidad de Chile, Chile. catalinaleroy@yahoo.es
authors.forename: Catalina
authors.initials: C
authors.lastname: Le Roy
authors.forename: Marco
authors.initials: M
authors.lastname: Reyes
authors.forename: José Miguel
authors.initials: JM
authors.lastname: González
authors.forename: Francisco
authors.initials: F
authors.lastname: Pérez-Bravo
authors.forename: Carlos
authors.initials: C
authors.lastname: Castillo-Durán
mesh_terms: D000469:Alkaline Phosphatase; D002118:Calcium; D002675:Child, Preschool; D002677:Chile; D005260:Female; D062306:Geography, Medical; D006801:Humans; D008297:Male; D009752:Nutritional Status; D010281:Parathyroid Hormone; D012621:Seasons; D013472:Sunlight; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000209:etiology*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D000469:Alkaline Phosphatase; D002118:Calcium