title: Prediction of Serum Zinc Levels in Mexican Children at 2 Years of Age Using a Food Frequency Questionnaire and Different Zinc Bioavailability Criteria.
abstract: BACKGROUND
  The 2006 Mexican National Health and Nutrition Survey documented a prevalence of zinc deficiency of almost 30% in children under 2 years of age.
  
  
  OBJECTIVE
  We sought to validate a food frequency questionnaire (FFQ) for quantifying dietary bioavailable zinc intake in 2-year-old Mexican children accounting for phytic acid intake and using serum zinc as a reference.
  
  
  METHODS
  This cross-sectional study was nested within a longitudinal birth cohort of 333 young children in Mexico City. Nonfasting serum zinc concentration was measured and dietary zinc intake was calculated on the basis of a semiquantitative FFQ administered to their mothers. The relationship between dietary zinc intake and serum zinc was assessed using linear regression, adjusting for phytic acid intake, and analyzed according to two distinct international criteria to estimate bioavailable zinc. Models were stratified by zinc deficiency status.
  
  
  RESULTS
  Dietary zinc, adjusted for phytic acid intake, explained the greatest proportion of the variance of serum zinc. For each milligram of dietary zinc intake, serum zinc increased on average by 0.95 μg/dL (0.15 μmol/L) (p = .06). When stratified by zinc status, this increase was 0.74 μg/dL (p = .12) for each milligram of zinc consumed among children with adequate serum zinc (n = 276), whereas among those children with zinc deficiency (n = 57), serum zinc increased by only 0.11 μg/dL (p = .82).
  
  
  CONCLUSIONS
  A semiquantitative FFQ can be used for predicting serum zinc in relation to dietary intake in young children, particularly among those who are zinc-replete, and when phytic acid or phytate intake is considered. Future studies should be conducted accounting for both zinc status and dietary zinc inhibitors to further elucidate and validate these findings.
authors.affiliation: National Institute of Public Health, Mexico alejandra.cantoral@insp.mx.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Cantoral
authors.affiliation: National Institute of Public Health, Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: Téllez-Rojo
authors.affiliation: National Institute of Public Health, Mexico.
authors.forename: Teresa
authors.initials: T
authors.lastname: Shamah-Levy
authors.affiliation: National Institute of Perinatology, Mexico.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Schnaas
authors.affiliation: National Institute of Public Health, Mexico.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Ávila
authors.affiliation: Human Nutrition Program, Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, USA Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Peterson
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA.
authors.forename: Adrienne S
authors.initials: AS
authors.lastname: Ettinger
mesh_terms: D001682:Biological Availability; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008800:Mexico; D010833:Phytic Acid / Q000008:administration & dosage; D011795:Surveys and Questionnaires; D015032:Zinc / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*
chemical_list: D010833:Phytic Acid; D015032:Zinc
keywords: bioavailable zinc; children; food frequency questionnaire; phytic acid; zinc status