title: Serum 25-hydroxyvitamin D levels among Mexican children ages 2 y to 12 y: a national survey.
abstract: OBJECTIVE
  The aim of this study was to assess the vitamin D status in preschool and school-age children in Mexico.
  
  
  METHODS
  25-hydroxyvitamin D (25-OH-D) serum concentrations were measured using a direct enzyme-linked immunosorbent assay commercial kit in a nationally representative sample of 1025 Mexican children ages 2 y to 12 y who participated in the 2006 Mexican National Health and Nutrition Survey.
  
  
  RESULTS
  Mean serum 25-OH-D concentration was 94.6 ± 47 nmol/L. Concentrations were lower in preschool children (2-5 y; 78.3 ± 37 nmol/L) than in school-aged children (6-12 y; 105.8 ± 51 nmol/L; P < 0.001). Children living in urban areas had lower levels (89.8 ± 36 nmol/L) than children from rural areas (108.1 ± 75 nmol/L; P < 0.05). Twenty-four percent of preschool children had vitamin D deficiency (25-OH-D < 50 nmol/L) compared with 10% of school-aged children (P < 0.05). Thirty percent of preschool children had vitamin D insufficiency (25-OH-D 50-74.9 nmol/L) compared with 18% of school-aged children (P < 0.05). In urban areas, 18% of children had vitamin D deficiency and 25% had insufficiency compared with 10% and 16% of children in rural areas, respectively (P < 0.05). Prevalence of severe vitamin D deficiency (25-OH-D < 20 nmol/L) was extremely low (0.3%).
  
  
  CONCLUSIONS
  Vitamin D deficiency and insufficiency are important public health problems in Mexican children.
authors: Center of Research in Nutrition and Health, National Institute of Public Health, Cuernavaca, Mexico. mario.flores@insp.mx
authors: Mario
authors: M
authors: Flores
authors: Nayeli
authors: N
authors: Macias
authors: Ana
authors: A
authors: Lozada
authors: Luz María
authors: LM
authors: Sánchez
authors: Eulises
authors: E
authors: Díaz
authors: Simon
authors: S
authors: Barquera
mesh_terms: D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D015995:Prevalence; D012720:Severity of Illness Index; D014505:Urban Population; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D