Vitamins
Folate
Folate is a water-soluble B vitamin. Its active forms take part in DNA synthesis and amino-acid metabolism.
Folate, also known as vitamin B9, is a family of related vitamin compounds. You obtain it from both plant and animal foods. Its active forms transfer small one-carbon units that are needed for processes including DNA synthesis and amino-acid metabolism. Folic acid is a specific form used in fortified foods and supplements. Although the names are sometimes used interchangeably, folic acid is not an exact synonym for the whole folate family.
Folate: vitamin B9 for DNA synthesis and cell division
Folate is a water-soluble B vitamin and the collective name for a family of related compounds. You obtain it from plant and animal foods. Its active forms transfer small one-carbon units that your body needs for processes including DNA synthesis and amino-acid metabolism.
Folate and folic acid are not the same
Folic acid is a specific synthetic form of folate used in fortified foods and supplements. Some supplements instead contain specified salts of 5-methyltetrahydrofolate, or 5-MTHF. Folate is therefore the broader term, rather than simply another name for folic acid.
What does folate do?
Folate has a role in cell division and contributes to normal blood formation and homocysteine metabolism. Its contributions to normal psychological function, normal immune-system function and the reduction of tiredness and fatigue are also authorised EU health claims — for foods meeting at least the conditions for a source of folate (Regulation (EU) No 432/2012).
These claims describe normal nutrient functions. They do not mean that extra or high-dose supplements prevent infections, improve memory or help with every cause of fatigue. Folate deficiency can cause megaloblastic anaemia, but folic acid is not the appropriate treatment for every type of anaemia.
Folic acid around conception
Supplemental folic acid increases maternal folate status. Low maternal folate status is a risk factor for neural tube defects in the developing foetus. The authorised EU health claim specifies 400 µg supplemental folic acid daily for at least one month before and up to three months after conception. It applies to supplements providing at least 400 µg folic acid per daily portion (Regulation (EU) No 1135/2014).
This is separate from total folate intake expressed in DFE. Neural tube defects have multiple risk factors; altering one factor may or may not have a beneficial effect. Higher prescribed doses may be appropriate in certain higher-risk circumstances — do not increase your dose independently.
What extra supplements have not clearly shown
Lowering homocysteine does not by itself establish protection against cardiovascular disease. Homocysteine-lowering B-vitamin supplements containing folic acid did not demonstrate reductions in heart attacks or all-cause mortality in the adult populations studied. Stroke outcomes need separate consideration, and combination trials cannot isolate folate's contribution.
In older adults overall, folic-acid-containing B-vitamin supplements did not show consistent cognitive benefits. Possible benefits in selected people with low nutrient status remain uncertain. Correcting an established deficiency is a different question.
Folate during cooking
Cooking and food processing can cause substantial folate losses. The amount lost depends on the food and preparation method, so a single loss percentage cannot be applied to every case.
How nutrition works
Maternal tissue growth in pregnancy
Red blood cell formation
Homocysteine metabolism
Psychological function
Folate contributes to normal psychological function. [2]
Immune system
Tiredness and fatigue
Cell division
Neural tube defects
Cardiovascular health
Homocysteine-lowering B-vitamin regimens containing folic acid may modestly reduce stroke risk in studied at-risk populations, but show no clear benefit for heart attacks or overall mortality. [4]
Cognitive function
B-vitamin supplements containing folic acid produce little or no average improvement in global cognitive function in mainly cognitively healthy older adults. [3]
Statements & evidence
Folate is a collective term for a family of water-soluble B-vitamin compounds. [7]
The term covers several related forms, rather than folic acid alone.
Naturally occurring food folates and synthetic folic acid are different forms of folate. [8]
Folic acid is used in fortified foods and supplements. Some supplements instead contain specified salts of 5-methyltetrahydrofolate (5-MTHF).
Dietary folate equivalents (DFE) account for differences in the bioavailability of folate forms. [7][8]
EFSA uses a conversion factor of 1.7 for folic acid relative to natural food folate. Conversion factors for supplemental 5-MTHF can depend on dose. Amounts expressed in µg DFE are therefore not automatically equivalent to µg of folic acid.
EFSA sets a population reference intake of 330 µg dietary folate equivalents per day for adults, an adequate intake of 600 µg during pregnancy, and a population reference intake of 500 µg during lactation. [7]
These values describe total folate intake in dietary folate equivalents (DFE). They are not supplement doses and should not be confused with the separate intake of 400 µg supplemental folic acid around conception.
Supplemental folic acid intake increases maternal folate status. Low maternal folate status is a risk factor in the development of neural tube defects in the developing foetus. [5][9]
This claim is authorised only for food supplements providing at least 400 µg folic acid per daily portion. The target population is women of child-bearing age. The beneficial effect is obtained with 400 µg supplemental folic acid daily for at least one month before and up to three months after conception. Neural tube defects have multiple risk factors; altering one of these factors may or may not have a beneficial effect.
Food processing and cooking can cause substantial folate losses. [8]
The amount lost depends on the food and preparation method. A single loss percentage cannot be applied universally.
EFSA sets an adult tolerable upper intake level of 1,000 µg per day for the combined intake of folic acid and specified 5-MTHF salts. Naturally occurring food folates are not covered by this limit. [8]
The level also applies during pregnancy and lactation, and to the specified 5-MTHF salts under their authorised conditions of use. It covers intake from fortified foods and supplements. It is a safety limit, not an intake target.
Folic acid can correct the megaloblastic anaemia associated with vitamin B12 deficiency without resolving the underlying vitamin B12 deficiency. [8]
This can mask vitamin B12 deficiency. It is a safety consideration, not an additional benefit of folic acid.
Safety information
Upper level · Adults
Upper limit for added folate
EFSA's adult upper limit is 1,000 µg daily, including during pregnancy and breastfeeding. It applies to the combined intake of folic acid and the assessed calcium and glucosamine salts of 5-MTHF from supplements and fortified foods; naturally occurring food folate is excluded. The limit concerns long-term intake, is not an intake target and is not an acute poisoning threshold. Higher medical doses require clinical supervision. [8][11]
Upper level · Children and adolescents (1–17 years)
Children have lower upper limits
EFSA's daily upper limits are: ages 1–3, 200 µg; 4–6, 300 µg; 7–10, 400 µg; 11–14, 600 µg; and 15–17, 800 µg. They cover the combined intake of folic acid and the assessed 5-MTHF salts from supplements and fortified foods, not naturally occurring food folate. Do not choose an adult-dose supplement for a child without professional advice. [8][11]
Upper level
Seek advice on folate supplements for infants
For infants aged 4–11 months, EFSA sets an upper limit of 200 µg daily for added folate forms from fortified foods and supplements. This is not a recommended supplement dose. Give an infant folate supplements only with paediatric advice; naturally occurring food folate is excluded from this limit. [8][11]
Contraindication
Do not treat vitamin B12 deficiency with folic acid alone
With known or suspected vitamin B12 deficiency, pernicious anaemia or unexplained megaloblastic anaemia, folic acid must not be the only treatment. It can improve the blood count without treating the neurological problem, potentially delaying diagnosis. Have the cause of the anaemia and your B12 status assessed before treatment. [12][8]
Side effect
Possible digestive side effects
Oral folic acid can cause nausea, bloating, flatulence and reduced appetite. These warnings concern folic acid preparations, not ordinary consumption of folate-rich foods. If symptoms persist, speak to a clinician or pharmacist. [13]
Contraindication
Known allergy to the preparation
Do not take a folic acid preparation if you are allergic to folic acid or one of its ingredients. Severe allergic reactions, including anaphylaxis, are documented; their frequency is unknown. Breathing difficulty, tongue or throat swelling, or collapse after taking it requires immediate emergency medical help. [12]
Interaction
Methotrexate for cancer: check before supplementing
If you receive methotrexate for cancer, folate supplements could interfere with its effects. Start or change these supplements only as directed by your oncology team. Folinic acid used in specific treatment protocols is different from folic acid and must not be substituted on your own. [3][14]
Interaction
Low-dose methotrexate: do not stop prescribed folate
With low-dose methotrexate for rheumatoid arthritis, folic or folinic acid is often deliberately prescribed to reduce side effects. This is different from methotrexate treatment for cancer. Follow your prescribed schedule and do not change the dose or timing on your own. [14]
Interaction
Interactions with certain antiseizure medicines
Phenytoin can lower folate status, while added folic acid can lower phenytoin concentrations and impair seizure control. Warnings also apply to phenobarbital and primidone. Discuss starting, stopping or changing folic acid with your treatment team; blood-level monitoring may be needed. [15][12]
Interaction
Sulfasalazine can reduce folate absorption
Sulfasalazine can inhibit intestinal folate absorption and contribute to deficiency. If you take it, discuss with your treatment team whether you need a folate supplement. This interaction does not mean you should generally avoid folate. [3]
Interaction
Check high-dose folic acid with fluorouracil
If you receive fluorouracil, do not add high-dose folic acid on your own: product information warns of severe diarrhoea with co-administration. Prescribed folinic acid within a chemotherapy protocol is different and must not be changed independently. [12]
Interaction
Folic acid is part of pemetrexed treatment
Blanket advice to avoid folate during all chemotherapy would be wrong. With pemetrexed, prescribed folic acid and vitamin B12 are required to reduce treatment toxicity. Follow your oncology team's instructions and do not stop these supplements on your own. [16]
Interaction
Check high-dose folic acid with antifolate medicines
With trimethoprim, proguanil or pyrimethamine, product information warns that high-dose folic acid may affect treatment, with possible mutual inhibition of effects. How often this causes clinical problems is unclear. Have a clinician or pharmacist check high-dose supplementation beforehand. [12]
Caution · Pregnant women
Higher pregnancy doses need clinical guidance
Pregnancy is not a contraindication to folic acid. For certain higher-risk pregnancies, prescribed doses above the general upper limit may be appropriate. Do not increase your dose independently, particularly if you take antiseizure medicines; follow your individual clinical recommendation. [17][15]
Frequently asked questions
What is the difference between folate and folic acid?
Folate is the collective term for a family of water-soluble B-vitamin compounds. Folic acid is a specific synthetic form used in fortified foods and supplements; some supplements contain 5-MTHF salts instead.
How much folate do I need each day?
EFSA sets a population reference intake of 330 µg dietary folate equivalents (DFE) daily for adults outside pregnancy and breastfeeding. During pregnancy, the adequate intake is 600 µg DFE; during breastfeeding, the population reference intake is 500 µg DFE. These values cover total intake and are not supplement doses.
Why is folic acid important before pregnancy?
Supplemental folic acid increases maternal folate status; low maternal folate status is a risk factor for neural tube defects in the developing foetus. The EU-authorised claim specifies 400 µg supplemental folic acid daily for at least one month before and up to three months after conception. Higher doses for certain higher-risk circumstances need clinical guidance.
Can I get too much folate?
EFSA's adult upper limit is 1,000 µg daily for the combined intake of folic acid and the assessed 5-MTHF salts from supplements and fortified foods. Naturally occurring food folate is excluded. The limit also applies during pregnancy and breastfeeding and is not an intake target; higher medical doses require clinical supervision.
Is folate lost during cooking?
Yes, cooking and food processing can cause substantial folate losses. The amount lost depends on the food and preparation method, so a single loss percentage does not apply to every case.
More entries
Vitamin A
Vitamin A is an essential, fat-soluble vitamin. Your diet supplies it as preformed vitamin A or as precursors from plant foods.
Vitamin B12
Vitamin B12 is an essential, water-soluble vitamin. Your body needs it for normal nervous-system function, red blood cell formation and DNA synthesis.
Vitamin C
Vitamin C is an essential, water-soluble vitamin that you need to obtain through your diet. Its principal chemical form is L-ascorbic acid.
Vitamin D
Vitamin D is a fat-soluble vitamin. The term mainly covers vitamins D₂ and D₃; your body can produce D₃ in the skin through exposure to UVB radiation.
Vitamin K
Vitamin K is an essential, fat-soluble vitamin. Your body needs it to activate proteins involved in blood clotting and bone metabolism.
Vitamin B6
Vitamin B6 is a water-soluble vitamin. Its active forms support many metabolic processes, particularly amino-acid metabolism.
Sources
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- 02European Commission · 2012Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children's development and healthOpen source
- 03National Institutes of Health, Office of Dietary SupplementsFolate - Health Professional Fact SheetOpen source
- 04Cochrane · 2017Homocysteine-lowering interventions (B-complex vitamin therapy) for preventing cardiovascular eventsOpen source
- 05Official Journal of the European Union · 2014Commission Regulation (EU) No 1135/2014 on the authorisation of a health claim made on foods and referring to the reduction of disease riskOpen source
- 06Cochrane · 2015Folic acid supplements before conception and in early pregnancy (up to 12 weeks) for the prevention of birth defectsDe-Regil et al.Open source
- 07EFSA Journal · 2014Scientific Opinion on Dietary Reference Values for folateOpen source
- 08EFSA Journal · 2023Scientific opinion on the tolerable upper intake level for folateDOI 10.2903/j.efsa.2023.8353
- 09Official Journal of the European Union · 2006Regulation (EC) No 1924/2006 on nutrition and health claims made on foodsOpen source
- 10European Parliament and Council of the European Union · 2011Regulation (EU) No 1169/2011 on the provision of food information to consumersOpen source
- 11European Food Safety AuthoritySummary tables of tolerable upper intake levels for vitamins and minerals, version 8Open source
- 12Health Products Regulatory Authority · 2025Folic acid medicine: Summary of Product CharacteristicsOpen source
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- 14CochraneFolic acid or folinic acid for reducing side effects of methotrexate for people with rheumatoid arthritisOpen source
- 15NHS Specialist Pharmacy ServiceUsing folic acid and phenytoin safelyOpen source
- 16European Medicines AgencyALIMTA (pemetrexed): product informationOpen source
- 17National Institute for Health and Care ExcellenceMaternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to 5 years — RecommendationsOpen source
- 18European Commission · 2025Consolidated text of Commission Regulation (EU) No 432/2012, 20 August 2025Open source
- 19Deutsche Gesellschaft für ErnährungFAQ FolatOpen source
- 202024Folic acid supplementation for stroke prevention: A systematic review and meta-analysis of 21 randomized clinical trials worldwidePubMed 38824900Open source