title: Total folate and folic acid intake from foods and dietary supplements in the United States: 2003-2006.
abstract: BACKGROUND
  The term total folate intake is used to represent folate that occurs naturally in food as well as folic acid from fortified foods and dietary supplements. Folic acid has been referred to as a double-edged sword because of its beneficial role in the prevention of neural tube defects and yet possible deleterious effects on certain cancers and cognitive function. Previous monitoring efforts did not include folic acid from dietary supplements and are therefore not complete.
  
  
  OBJECTIVE
  Our objective was to combine data on dietary folate (as measured by two 24-h recalls) and folic acid from dietary supplements (collected with a 30-d frequency questionnaire) with the use of the bias-corrected best power method to adjust for within-person variability.
  
  
  METHODS
  The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, cross-sectional survey. Linear contrasts were constructed to determine differences in dietary and total folate intake for age and racial-ethnic groups by sex; prevalence of inadequate and excessive intakes is presented.
  
  
  RESULTS
  In 2003-2006, 53% of the US population used dietary supplements; 34.5% used dietary supplements that contained folic acid. Total folate intake (in dietary folate equivalents) was higher for men (813 +/- 14) than for women (724 +/- 16) and higher for non-Hispanic whites (827 +/- 19) than for Mexican Americans (615 +/- 11) and non-Hispanic blacks (597 +/- 12); 29% of non-Hispanic black women had inadequate intakes. Total folate and folic acid intakes are highest for those aged > or =50 y, and 5% exceed the Tolerable Upper Intake Level.
  
  
  CONCLUSIONS
  Improved total folate intake is warranted in targeted subgroups, which include women of childbearing age and non-Hispanic black women, whereas other population groups are at risk of excessive intake.
authors.affiliation: Office of Dietary Supplements and the National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-7517, USA. baileyr@mail.nih.gov
authors.forename: Regan L
authors.initials: RL
authors.lastname: Bailey
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Dodd
authors.forename: Jaime J
authors.initials: JJ
authors.lastname: Gahche
authors.forename: Johanna T
authors.initials: JT
authors.lastname: Dwyer
authors.forename: Margaret A
authors.initials: MA
authors.lastname: McDowell
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Yetley
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Sempos
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Burt
authors.forename: Kathy L
authors.initials: KL
authors.lastname: Radimer
authors.forename: Mary Frances
authors.initials: MF
authors.lastname: Picciano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004032:Diet; D019587:Dietary Supplements / Q000032:analysis*; D004734:Energy Metabolism; D005006:Ethnicity; D005247:Feeding Behavior; D005260:Female; D005492:Folic Acid / Q000032:analysis* / Q000378:metabolism; D005504:Food Analysis; D005527:Food, Fortified; D006306:Health Surveys; D006630:Hispanic or Latino; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D017058:Mexican Americans; D008875:Middle Aged; D044469:Racial Groups; D012727:Sex Characteristics; D014481:United States; D044465:White People; D055815:Young Adult
chemical_list: D005492:Folic Acid