Dietary Folate Equivalents: Interpretation and Application

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Abstract

The 1998 Dietary Reference Intakes express the new Recommended Dietary Allowances for folate in dietary folate equivalents (“DFEs”), which account for differences in the absorption of naturally occurring food folate and the more bioavailable synthetic folic acid. The quantity of dietary folate equivalents occurring naturally in food equals the micrograms of folate as reported, and the dietary folate equivalents provided by fortified foods equal the micrograms of food folate plus 1.7 times the micrograms of added folic acid. Currently, the use of dietary folate equivalents is recommended for planning and evaluating the adequacy of people's folate intake. As a result of new US Food and Drug Administration regulations, folic acid has been added to enriched cereal grains and thus affects hundreds of food products. To help dietetics professionals plan and evaluate diets that include enriched cereal grain products, we estimated the dietary folate equivalent content of a selection of foods using data supplied by the US Department of Agriculture and grouped the foods by dietary folate equivalent content. J Am Diet Assoc. 2000;100:88-94.

Section snippets

What are Dietary Folate Equivalents?

Dietary folate equivalents are units that account for the differences in the absorption of food folate and of synthetic folic acid obtained from dietary supplements or food fortified with folic acid. The polyglutamate side chain of food folate must be cleaved before absorption can occur. This converts food folate to the monoglutamate form, which is taken up by a specific carrier in the cell membrane of the small intestine (4). When synthetic folic acid (a monoglutamate) is consumed as a

Accuracy in Estimating Requirements

The physiologic requirement for folate represents the amount of folate the body requires after the folate is absorbed—the amount that actually enters the bloodstream. If the folate is supplied entirely in the form of food folate, more must be ingested to meet the physiologic requirement than would be true for synthetic folic acid. The Institute of Medicine's Subcommittee on Folate, B Vitamins, and Choline used several metabolic studies to estimate the folate requirement (1). Some of these

Reduction of the Risk of Neural Tube Defects

As indicated by footnote e in Table 1, the recommendation for women capable of becoming pregnant and in the first month of pregnancy is to consume 400 μg folic acid per day from fortified foods and/or supplements—in addition to intake of food folate from a varied diet (1). Because this recommendation refers specifically to synthetic folic acid, it differs from the RDA for folate, and dietary folate equivalents do not apply. Only folic acid from fortified food or supplements should be counted

Conclusion

The report Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B-6, Folate, Vitamin B-12, Pantothenic Acid, Biotin, and Choline(1) includes the following major recommendation: “Because of the difference in the bioavailability of food folate and synthetic folic acid, it is recommended that both food folate and synthetic folic acid be included in tables of food composition and in reports of intake. In other words, the content or intake of naturally occurring food folate should be

References (23)

  • A.F. Subar et al.

    Dietary sources of nutrients among US adults, 1989 to 1991

    J Am Diet Assoc.

    (1998)
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