Folic acid (Vitamin B9)
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Every diet
It is chemically synthesized.
No carbohydrate.
Safe in small amounts; may bother some people or raise blood sugar.
Rules by country
Folic acid is permitted as a nutrient additive in the US under 21 CFR 172.345, and the standard of identity for enriched flour in 21 CFR 137.165 requires 0.7 mg per pound alongside thiamin, riboflavin, niacin and iron. It has no E-number, because the EU authorizes it as a nutrient for fortification rather than as an additive, and EFSA set an upper level of 0.6 mg a day for adults for folic acid from fortified foods and supplements, since high intakes can mask a vitamin B12 deficiency.
What is it?
Folate is the name for the whole family of related molecules; folic acid is the manufactured version of it. The synthetic form is more stable and more bioavailable than the folates in leafy greens, which is why the fortification works so reliably. It is one of the four nutrients that enriched flour is required to carry in the United States, alongside thiamin, riboflavin, niacin and iron.
Where it comes from: Made chemically rather than extracted from food. It is the synthetic form of folate and it is stable, which is exactly why it is the form used to fortify flour and to put in supplements.
Why it’s in food
- Flour enrichment
- Breakfast cereals
- Supplements
- Pregnancy supplements
- Folate-fortified products
Often found in
Also listed as: Folic acid, Vitamin B9, Pteroyl-L-glutamic acid, Folate, Folic acid, synthetic, Calcium folinate
Health & gut impact
Folic acid taken before conception and in early pregnancy substantially reduces the risk of neural tube defects such as spina bifida, which is why fortification of flour and the advice to take folic acid before pregnancy are both routine.
US CDC, folic acid and neural tube defect prevention
Folic acid corrects the anemia caused by low B12 without correcting the neurological damage, so the deficiency can progress unnoticed. That is the main reason EFSA set an upper level of 0.6 mg a day for adults rather than leaving it open.
EFSA Panel on Nutrition, Novel Foods and Food Allergens, opinion on folic acid (2014)
Folic acid from fortified food is absorbed more readily than the folates in vegetables, and the body handles the two differently. Anyone with a condition affecting folate metabolism, or taking medication that interferes with it, should ask a doctor before taking high doses.
EFSA Panel on Nutrition, Novel Foods and Food Allergens, opinion on folic acid (2014)
What can I use instead?
Ratio: Use as the other B vitamin in an enriched loaf
Best for: Matching the enriched flour standard
Related
More vitamins & minerals:
Common questions
Is folic acid in bread safe?
Yes. The amounts used in flour enrichment are small and well inside the tolerable level, and the fortification is one of the most effective public health interventions in nutrition because it reaches everyone who eats bread.
Why is folic acid limited to 0.6 mg a day?
Because above that level it can correct the anemia of a vitamin B12 deficiency while leaving the neurological damage to progress. The limit applies to folic acid from fortified food and supplements, not to the folate naturally present in food.
Is folic acid the same as folate?
Folic acid is the synthetic form of folate. Folate is the family of molecules that includes folic acid and the folates found in food, and the body converts them all into the same active form.
Is Vitamin B9 safe?
Use in moderation (74/100). Folic acid is permitted as a nutrient additive in the US under 21 CFR 172.345, and the standard of identity for enriched flour in 21 CFR 137.165 requires 0.7 mg per pound alongside thiamin, riboflavin, niacin and iron. It has no E-number, because the EU authorizes it as a nutrient for fortification rather than as an additive, and EFSA set an upper level of 0.6 mg a day for adults for folic acid from fortified foods and supplements, since high intakes can mask a vitamin B12 deficiency.
Is Vitamin B9 vegan?
Yes. It is chemically synthesized.
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Scientific sources & regulatory citations
- 21 CFR 172.345 (US FDA)
- US CDC, folic acid and neural tube defect prevention
- EFSA Panel on Nutrition, Novel Foods and Food Allergens, opinion on folic acid (2014)
CAS 58-14-2