title: Identifying areas with vitamin A deficiency: the validity of a semiquantitative food frequency method.
abstract: OBJECTIVE
  The prevalence of vitamin A deficiency has traditionally been assessed through xerophthalmia or biochemical surveys. The cost and complexity of implementing these methods limits the ability of nonresearch organizations to identify vitamin A deficiency. This study examined the validity of a simple, inexpensive food frequency method to identify areas with a high prevalence of vitamin A deficiency.
  
  
  METHODS
  The validity of the method was tested in 15 communities, 5 each from the Philippines, Guatemala, and Tanzania. Serum retinol concentrations of less than 20 micrograms/dL defined vitamin A deficiency.
  
  
  RESULTS
  Weighted measures of vitamin A intake six or fewer times per week and unweighted measures of consumption of animal sources of vitamin A four or fewer times per week correctly classified seven of eight communities as having a high prevalence of vitamin A deficiency (i.e., 15% or more preschool-aged children in the community had the deficiency) (sensitivity = 87.5%) and four of seven communities as having a low prevalence (specificity = 57.1%).
  
  
  CONCLUSIONS
  This method correctly classified the vitamin A deficiency status of 73.3% of the communities but demonstrated a high false-positive rate (42.9%).
authors.affiliation: Population Council, New York, NY 10017, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Sloan
authors.forename: D
authors.initials: D
authors.lastname: Rosen
authors.forename: T
authors.initials: T
authors.lastname: de la Paz
authors.forename: M
authors.initials: M
authors.lastname: Arita
authors.forename: C
authors.initials: C
authors.lastname: Temalilwa
authors.forename: N W
authors.initials: NW
authors.lastname: Solomons
mesh_terms: D002675:Child, Preschool; D004034:Diet Surveys; D005069:Evaluation Studies as Topic; D005260:Female; D006166:Guatemala / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D009752:Nutritional Status; D010679:Philippines / Q000453:epidemiology; D015203:Reproducibility of Results; D013636:Tanzania / Q000453:epidemiology; D014801:Vitamin A / Q000008:administration & dosage / Q000097:blood; D014802:Vitamin A Deficiency / Q000453:epidemiology*
chemical_list: D014801:Vitamin A