Quick answer
Adults need 400 mcg DFE of folate a day, 600 mcg DFE in pregnancy and 500 mcg DFE while breastfeeding. From supplements and fortified foods, adults should stay at or under 1,000 mcg of folic acid a day. Anyone who could become pregnant is advised to take 400 mcg of folic acid daily.1
Key facts
- 400 mcg DFE equals 240 mcg of folic acid taken with food, or 400 mcg of folate from food.1
- Adult supplements usually hold 400 to 800 mcg of folic acid, printed on labels as 680 to 1,360 mcg DFE.2
- The 1,000 mcg upper limit for folic acid works out to about 1,667 mcg DFE.2
- No official factor converts methylfolate to DFE, so two labels can count the same amount differently.2
Recommended amounts and upper limits by age
| Age or stage | Recommended, mcg DFE | Upper limit for supplements and fortified foods, mcg |
|---|---|---|
| Birth to 6 months | 65 | Not set |
| 7 to 12 months | 80 | Not set |
| 1 to 3 years | 150 | 300 |
| 4 to 8 years | 200 | 400 |
| 9 to 13 years | 300 | 600 |
| 14 to 18 years | 400 | 800 |
| 19 and over | 400 | 1,000 |
| Pregnancy | 600 | 800 under 19, 1,000 from 19 |
| Breastfeeding | 500 | 800 under 19, 1,000 from 19 |
The infant figures are adequate intakes based on what healthy breastfed babies take in. NIH says breast milk, formula and food should be a baby's only sources of folate.2
Reading DFE on a label
1 mcg DFE equals 1 mcg of folate from food, 0.6 mcg of folic acid taken with food, or 0.5 mcg of folic acid taken on an empty stomach.2
Labels count folic acid at 1.7 mcg DFE per microgram, so 400 mcg of folic acid is listed as 680 mcg DFE.2
So a supplement with 400 mcg of folic acid meets the adult recommendation on its own, before any food is counted. The upper limit is set in plain micrograms of folic acid rather than DFE, which is why it can look smaller than the DFE figure printed on the same label.2
Supplements for adults usually provide 680 to 1,360 mcg DFE, which is 400 to 800 mcg of folic acid. Children's multivitamins usually provide 340 to 680 mcg DFE.2
If you could become pregnant
US advice is 400 mcg of folic acid a day from supplements, fortified foods or both, in addition to the folate in a varied diet. The US Preventive Services Task Force recommends a daily supplement with 400 to 800 mcg.1,3
During pregnancy the target becomes 600 mcg DFE from all sources, which some women find hard to reach from food alone. Obstetricians recommend a prenatal vitamin for most pregnant women.2
Methylfolate dosage, and MTHFR
Methylfolate has no official DFE conversion. The FDA lets makers count it with the folic acid factor of 1.7 or a lower factor of their own, so compare the micrograms of methylfolate on the label as well as the DFE figure.2
NIH gives no separate amount for people with an MTHFR variant and calls the research on supplements for them inconclusive. Its consumer fact sheet says not to go above the upper limit with folate from supplements or fortified foods unless a health care provider recommends it.1,2
If you could become pregnant, NIH and the CDC keep the advice at 400 mcg of folic acid a day, not methylfolate, even with the variant.1,2
Who goes over the limit
About 5% of adults aged 51 to 70, and of men over 70, take in more folic acid than the upper limit, mainly from supplements.2
Fortified foods count toward the limit along with supplements, and amounts add up across products. People who take supplements containing folic acid get an average of 712 mcg DFE from those supplements alone.2
Doses above the limit
The upper limit for adults is 1,000 mcg a day of folate from supplements and fortified foods, which for folic acid equals about 1,667 mcg DFE. It is 800 mcg for teens aged 14 to 18. Folate naturally present in food has no limit, and the limits do not apply to higher doses taken under medical supervision.1,2
The folic acid prescribing label says daily doses above 1 mg do not add to the blood response, with most of the excess passing into urine. It also says that, outside pregnancy and breastfeeding, more than 0.4 mg a day should not be given until pernicious anemia has been ruled out.4
Doses well above the limit, such as those used after a pregnancy affected by a neural tube defect or in research on depression, are for use only under medical supervision.2
Questions people ask
Is 800 mcg of folic acid too much?
Not for most adults. It is under the 1,000 mcg upper limit and at the top of the 400 to 800 mcg range the US Preventive Services Task Force gives for anyone who could become pregnant. Count fortified foods too, because the limit covers them.1,3
Is 1 mg of folic acid a day safe?
1 mg is 1,000 mcg, the adult upper limit for folic acid from supplements and fortified foods, so fortified foods can take you past it. Take that much only if a doctor advises it, ideally after a vitamin B12 check.1,4
Does folate from food count toward the upper limit?
No. Only folic acid and other folate from supplements and fortified foods count. Natural folate in food has no limit, since high intakes from food have not been reported to cause adverse effects.2
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Sources
- National Institutes of Health, Office of Dietary Supplements. Folate: Fact Sheet for Consumers. Updated November 1, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Folate: Fact Sheet for Health Professionals. Updated November 30, 2022. Opened 2026-10-07.
- US Preventive Services Task Force. Folic Acid Supplementation to Prevent Neural Tube Defects: US Preventive Services Task Force Reaffirmation Recommendation Statement. JAMA. 2023;330(5):454-459. Opened 2026-10-07.
- Folic acid tablets, 1 mg: prescribing information (Rising Pharma Holdings). DailyMed, U.S. National Library of Medicine. Published August 3, 2026. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.