Quick answer
DFE stands for dietary folate equivalents, the unit labels use for folate. It adjusts for folic acid being absorbed better than natural food folate: 1 mcg of folic acid taken with food counts as 1.7 mcg DFE. A supplement with 400 mcg of folic acid lists 680 mcg DFE.1,2
Key facts
- The Food and Nutrition Board created DFEs because about 85 percent of folic acid taken with food is absorbed, against about 50 percent of the folate in food.1,2
- 1 mcg DFE equals 1 mcg of food folate, 0.6 mcg of folic acid taken with food, or 0.5 mcg of folic acid taken on an empty stomach.2
- Labels give folate in mcg DFE with a %DV; when folic acid is added, its amount in mcg follows in parentheses.3,4
- The Daily Value for folate is 400 mcg DFE for adults and children 4 and older.5
- For L-5-MTHF and other synthetic folates, FDA accepts 1.7 or a maker's own conversion factor, as long as it is not above 1.7.1,2
The arithmetic on a label
The FDA formula is mcg DFE = mcg of naturally occurring folate + (1.7 × mcg of folic acid). Food folate counts once and folic acid counts 1.7 times.1
| What one serving contains | Folate on the label | % DV |
|---|---|---|
| 400 mcg folic acid | 680 mcg DFE (400 mcg folic acid) | 170% |
| 200 mcg calcium L-5-MTHF, using a factor of 1.7 | 340 mcg DFE | 85% |
| 50 mcg food folate, 100 mcg folic acid and 150 mcg L-5-MTHF | 475 mcg DFE (100 mcg folic acid) | 119% |
In the second example nothing appears in parentheses, because none of the folate is folic acid. FDA's consumer page makes the same point: a %DV for folate with no mcg of folic acid in parentheses means folic acid was not added.1,4
Why the numbers look bigger than before
Before the 2016 rule, folate was labeled in plain mcg against a 400 mcg reference. Now the same 400 mcg of folic acid appears as 680 mcg DFE, or 170% of the Daily Value. The product did not change; the unit did.1
NIH lists common supplement amounts for adults as 680 to 1,360 mcg DFE, which is 400 to 800 mcg of folic acid.2
The upper limit is in plain mcg
The adult Tolerable Upper Intake Level covers synthetic folate from supplements and fortified foods, and it is stated in mcg, not mcg DFE: 1,000 mcg of folic acid, about 1,667 mcg DFE. No upper limit is set for folate from food.2
Pregnancy and breastfeeding
Folate needs rise to 600 mcg DFE a day in pregnancy and 500 mcg DFE while breastfeeding. The FDA advises anyone who could become pregnant to get 400 mcg of folic acid a day from fortified foods, supplements or both, on top of the folate in a varied diet. Ask your doctor or pharmacist which amount fits you.4
Questions people ask
Is 680 mcg DFE the same as 400 mcg of folic acid?
Yes, for folic acid taken with food: 400 × 1.7 = 680.1
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Sources
- U.S. Food and Drug Administration. Converting Units of Measure for Folate, Niacin, and Vitamins A, D, and E on the Nutrition and Supplement Facts Labels: Guidance for Industry. August 2019. Opened 2026-10-07.
- NIH Office of Dietary Supplements. Folate: Fact Sheet for Health Professionals. Updated November 30, 2022. Opened 2026-10-07.
- Code of Federal Regulations, Title 21, Section 101.9: Nutrition labeling of food. Legal Information Institute, Cornell Law School (eCFR text). Opened 2026-10-07.
- U.S. Food and Drug Administration. Folate and Folic Acid on the Nutrition and Supplement Facts Labels. Content current as of March 5, 2024. Opened 2026-10-07.
- U.S. Food and Drug Administration. Daily Value on the Nutrition and Supplement Facts Labels. Content current as of March 5, 2024. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.