How much folate (vitamin B9) do adults need?

Adults need 400 micrograms DFE a day, or 600 in pregnancy (US, NIH). In the UK: 200 micrograms a day, plus 400 micrograms of folic acid a day from before pregnancy until week 12 (NHS).

What is the upper limit for folate (vitamin B9)?

US: 1,000 micrograms of folic acid a day from supplements and fortified foods. UK (NHS): up to 1,000 micrograms (1 milligram) of folic acid a day from supplements is unlikely to cause harm.

Which foods have folate (vitamin B9)?

Leafy greens, beans and peas, peanuts, sunflower seeds, liver, fortified bread and cereals.

What should I watch out for with folate (vitamin B9)?

The upper limit is for folic acid. 1 microgram of folic acid counts as 1.7 micrograms DFE.

Folate (vitamin B9): what it does and how much you need

Folate (vitamin B9) helps make DNA and new cells, and is especially important before and during early pregnancy. Adults need 400 micrograms DFE a day, or 600 in pregnancy, and the upper limit is 1,000 micrograms of folic acid a day from supplements and fortified foods.

Checked 28 September 2026 with Supplement Check's data from the NIH fact sheet and NHS guidance · Adults only

General information, not medical advice. Check with a doctor or pharmacist before taking a supplement, especially if you are pregnant or breastfeeding, take any medicine, or are under 18.

In the UK

In the UK, adults need 200 micrograms a day, plus 400 micrograms of folic acid a day from before pregnancy until week 12, and the NHS says up to 1,000 micrograms (1 milligram) of folic acid a day from supplements is unlikely to cause harm.

How much you need and the upper limit

	US (NIH)	UK (NHS)
Adults need	400 micrograms DFE a day, or 600 in pregnancy	200 micrograms a day, plus 400 micrograms of folic acid a day from before pregnancy until week 12
Upper limit	1,000 micrograms of folic acid a day from supplements and fortified foods	Up to 1,000 micrograms (1 milligram) of folic acid a day from supplements

The UK figure is the amount the NHS says is unlikely to cause harm. Figures are for adults.

Cautions

The upper limit is for folic acid. 1 microgram of folic acid counts as 1.7 micrograms DFE.

Food sources

Leafy greens
Beans and peas
Peanuts
Sunflower seeds
Liver
Fortified bread and cereals

Forms on the label

Methylfolate (5-MTHF) is an active form of folate, and the upper limit is set only for folic acid, not for methylfolate.

Dose questions

Is 1000 mcg of folic acid too much?

Quick answers

What does folate (vitamin B9) do?: Folate (vitamin B9) helps make DNA and new cells, and is especially important before and during early pregnancy.
How much folate (vitamin B9) do adults need?: Adults need 400 micrograms DFE a day, or 600 in pregnancy (US, NIH). In the UK: 200 micrograms a day, plus 400 micrograms of folic acid a day from before pregnancy until week 12 (NHS).
What is the upper limit for folate (vitamin B9)?: US: 1,000 micrograms of folic acid a day from supplements and fortified foods. UK (NHS): up to 1,000 micrograms (1 milligram) of folic acid a day from supplements is unlikely to cause harm.
Which foods have folate (vitamin B9)?: Leafy greens, beans and peas, peanuts, sunflower seeds, liver, fortified bread and cereals.
What should I watch out for with folate (vitamin B9)?: The upper limit is for folic acid. 1 microgram of folic acid counts as 1.7 micrograms DFE.

Sources

NIH Office of Dietary Supplements fact sheet
https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/
NHS vitamins and minerals guidance
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-b/

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