title: U.S. women of childbearing age who are at possible increased risk of a neural tube defect-affected pregnancy due to suboptimal red blood cell folate concentrations, National Health and Nutrition Examination Survey 2007 to 2012.
abstract: BACKGROUND
  Red blood cell (RBC) folate concentrations are a potential biomarker of folate-sensitive neural tube defect (NTD) risk in the population. The purpose of this analysis was to describe women in the U.S. population with RBC folate concentrations below those associated with optimal NTD prevention.
  
  
  METHODS
  We used data from the 2007 to 2012 National Health and Nutrition Examination Survey (NHANES) to assess the RBC folate status of U.S. women of childbearing age relative to risk categories for NTD risk based on RBC folate concentrations. We defined suboptimal RBC folate concentrations as those associated with a prevalence of ≥9 NTDs per 10,000 live births.
  
  
  RESULTS
  Among nonpregnant women age 12 to 49 years, 22.8% (95% Confidence Interval: 21.1, 24.6) had suboptimal RBC folate concentrations. Women had greater odds of having a suboptimal RBC folate concentration if they did not use dietary supplements containing folic acid; had mandatorily fortified enriched cereal grain products as their only source of folic acid; were non-Hispanic black or Hispanic; or were current smokers.
  
  
  CONCLUSIONS
  Based on RBC folate concentrations, we would predict that the majority of U.S. women of reproductive age are not at increased risk for folate sensitive NTDs in the presence of mandatory folic acid fortification. Prevention policies and programs can be aimed at population subgroups identified as having higher predicted risk for folate-sensitive NTDs based on RBC folate concentrations.
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Tinker
authors.affiliation: National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Heather C
authors.initials: HC
authors.lastname: Hamner
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia.
authors.forename: Yan Ping
authors.initials: YP
authors.lastname: Qi
authors.affiliation: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia.
authors.forename: Krista S
authors.initials: KS
authors.lastname: Crider
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005492:Folic Acid / Q000032:analysis / Q000097:blood*; D006801:Humans; D009436:Neural Tube Defects / Q000453:epidemiology*; D009749:Nutrition Surveys / Q000706:statistics & numerical data*; D011247:Pregnancy; D018570:Risk Assessment / Q000379:methods / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D005492:Folic Acid
keywords: NHANES; folic acid; fortification; neural tube defects; optimal RBC folate concentration