Campus Units

Statistics

Document Type

Article

Publication Version

Published Version

Publication Date

2010

Journal or Book Title

American Journal of Clinical Nutrition

Volume

91

Issue

1

First Page

64

Last Page

72

DOI

10.3945/ajcn.2009.28401

Abstract

Background: US adults have access to multiple sources of folic acid. The contribution of these sources to usual intakes above the tolerable upper intake level (UL) (1000 ug/d) and to folate and vitamin B-12 status is unknown. Objective: The objective was to estimate usual folic acid intake above the UL and adjusted serum and red blood cell folate, vitamin B-12, methylmalonic acid, and homocysteine concentrations among US adults by 3 major folic acid intake sources - enriched cereal-grain products (ECGP), ready-to-eat cereals (RTE), and supplements (SUP) - categorized into 4 mutually exclusive consumption groups. Design: We used data from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 (n = 8258). Results: Overall, 2.7% (95% CI: 1.9%, 3.5%) of adults consumed more than the UL of folic acid. The proportions of those who consumed folic acid from ECGP only, ECGP+RTE, ECGP+SUP, and ECGP+RTE+SUP were 42%, 18%, 25%, and 15%, respectively. Of 60% of adults who did not consume supplements containing folic acid (ECGP only and ECGP+RTE), 0% had intakes that exceeded the UL. Of 34% and 6% of adults who consumed supplements with an average of <400 and >400 ug folic acid/d, <1% and 47.8% (95% CI: 39.6%, 56.0%), respectively, had intakes that exceeded the UL. Consumption of RTE and/or supplements with folic acid was associated with higher folate and vitamin B-12 and lower homocysteine concentrations, and consumption of supplements with vitamin B-12 was associated with lower methylmalonic acid concentrations (P < 0.001). Conclusion: At current fortification levels, US adults who do not consume supplements or who consume an average of <400 ug folic acid/d from supplements are unlikely to exceed the UL in intake for folic acid.

Comments

This article is from American Journal of Clinical Nutrition 91 (2010): 64, doi: 10.3945/ajcn.2009.28401.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

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