Quick answer
US guidelines set riboflavin at 1.3 mg a day for men and 1.1 mg for women, 1.4 mg in pregnancy and 1.6 mg while breastfeeding. European reference values are higher, at 1.6 mg for adults. No upper limit is set, but the gut absorbs only about 27 mg at a time.1,2,3
Key facts
- Children need 0.5 to 0.9 mg a day depending on age, and teens 1.0 to 1.3 mg.1
- Men in the United States average 2.5 mg a day from food, and women 1.8 mg.2
- EFSA sets 1.9 mg a day in pregnancy and 2.0 mg while breastfeeding.3
- Multivitamins commonly provide 1.3 mg, 100% of the Daily Value.2
Recommended amounts in the US and Europe
| Group | US recommended amount | European reference intake |
|---|---|---|
| Men | 1.3 mg | 1.6 mg |
| Women | 1.1 mg | 1.6 mg |
| Pregnancy | 1.4 mg | 1.9 mg |
| Breastfeeding | 1.6 mg | 2.0 mg |
Children need 0.5 mg a day at ages 1 to 3, 0.6 mg at 4 to 8 and 0.9 mg at 9 to 13. From 14 to 18, boys need 1.3 mg and girls 1.0 mg.1
The Daily Value used on food and supplement labels is 1.3 mg of riboflavin for adults and children aged 4 and older.2
Why the European numbers are higher
The two sets of values come from different methods. EFSA based its numbers on the intake at which riboflavin in urine starts to climb steeply, a sign that the body is saturated, and then added a margin for differences between people, including physical activity and a common variant of the MTHFR gene.3
EFSA found some signs that physical activity changes riboflavin status, but no clear link between how active people are and how much they need.3
In practice the gap matters less than it looks: the average man and woman in the United States already eat more riboflavin than either figure.2,3
How much people actually get
Adults in the United States average 2.5 mg of riboflavin a day from food for men and 1.8 mg for women. Counting supplements, men average 4.5 mg and women 4.7 mg.2
Fewer than 6% of people in the United States take in less riboflavin from food and supplements than the average requirement.2
In US survey data, lacto-ovo vegetarians took in slightly more riboflavin than people who eat meat: 2.3 mg against 2.1 mg a day.2
What happens with big doses
The gut absorbs at most about 27 mg of riboflavin from a single dose or meal. Uptake rises in step with the dose up to about 25 to 30 mg and then levels off.2,3,4
That cap is why a 100 mg or 400 mg tablet does not deliver its full amount to the body. Of what is absorbed, the body keeps little and passes the rest in urine, which turns bright yellow.2,4
What's in ours
What’s in ours
- Men's Multi: Vitamin B2, 7.5 mg per serving, from the label
High doses and who should ask first
Doses of 400 mg a day are used under medical guidance for migraine, and NIH reports no adverse effects at that level for at least three months. One small trial noted minor effects such as loose stools. Talk to your doctor before taking that much.1,2,5
- Ask first if you are pregnant or breastfeeding and want more than a prenatal vitamin provides
- Ask first if you have a condition that affects how you absorb riboflavin
- Tell your pharmacist about any high-dose B vitamin you take
Questions people ask
Is 400 mg of riboflavin too much?
No upper limit is set, and NIH reports no adverse effects from 400 mg a day for at least three months. The gut takes up only about 27 mg at a time, so most of it is not absorbed. Use doses that high only with a doctor's advice.2
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Sources
- Office of Dietary Supplements, National Institutes of Health. Riboflavin: Fact Sheet for Consumers. Updated May 11, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Riboflavin: Fact Sheet for Health Professionals. Updated May 11, 2022. Opened 2026-10-07.
- EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Dietary Reference Values for riboflavin. EFSA J. 2017;15(8):e04919. Opened 2026-10-07.
- Zempleni J, Galloway JR, McCormick DB. Pharmacokinetics of orally and intravenously administered riboflavin in healthy humans. Am J Clin Nutr. 1996;63(1):54-66. Opened 2026-10-07.
- Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis. A randomized controlled trial. Neurology. 1998;50(2):466-470. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.