Folic acid before pregnancy: when to start and for how long

This guide is for information only: it does not replace the advice of a doctor, midwife or pharmacist. Talk to one of them before starting a supplement.

The World Health Organization (WHO) recommends that all women, from the moment they begin trying to conceive until 12 weeks of pregnancy, take a folic acid supplement of 400 µg (0.4 mg) a day. It adds that folic acid should be started as early as possible, ideally before conception, to prevent neural tube defects such as spina bifida.

Why so early? The French health safety agency ANSES points out that vitamin B9 matters particularly in the first weeks of pregnancy and must be present in sufficient amounts from the very first day, whether the pregnancy was planned or not. Starting when you plan a baby, rather than when the test comes back positive, follows that logic.

A Cochrane review published in 2015 brought together five trials involving 7,391 women. Its authors found a protective effect of folic acid, alone or combined with other vitamins and minerals, against neural tube defects, with no clear effect on other birth defects.

After 12 weeks, the WHO recommends a daily supplement combining iron and folic acid during pregnancy: your doctor or midwife will tell you which one. This guide cites WHO and European Union references; to find out what applies to your situation in Morocco, ask your doctor or midwife.

In the European Union, a folic acid supplement may carry a reduction of disease risk claim authorised by Commission Regulation (EU) No 1135/2014 of 24 October 2014. Its official English wording is: “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.”

Conditions set by the same regulation: “The claim may be used only for food supplements which provide at least 400 µg of folic acid per daily portion.” and “Information shall be provided to the consumer that the target population is women of child-bearing age and the beneficial effect is obtained with a supplemental folic acid daily intake of 400 µg for at least one month before and up to three months after conception.”

Regulation (EC) No 1924/2006 (Article 14) adds that such a claim must come with a statement indicating that the disease to which the claim is referring has multiple risk factors and that altering one of these risk factors may or may not have a beneficial effect.

Another claim, this time for folate, is listed in Regulation (EU) No 432/2012: “Folate contributes to maternal tissue growth during pregnancy.” It may be used only for food which is at least a source of folate.

The two time frames are not worded the same way; the table below gives them as written. Your doctor or midwife will tell you which one to follow.

The WHO sets out specific care for women who have already had a pregnancy affected by a neural tube defect: they should be informed about the risk of recurrence, advised on the protective effect of folic acid around conception, offered higher-dose supplementation and encouraged to eat more folate-rich foods. That higher dose is not given here: it is a medical prescription.

This guide gives no dose to take and presents no “high dose” as something to decide for yourself. If you have such a history, a chronic illness or ongoing treatment, talk to your doctor before trying to conceive: they will set the dose and duration that suit you.

Before combining several supplements that contain folic acid or another form of folate (a pregnancy supplement and a multivitamin, for example), ask your doctor or pharmacist.

According to ANSES, vitamin B9 is a family of molecules: folates, found naturally in food, and folic acid, the synthetic form added to some foods (fortified foods and food supplements). On a German box, folic acid is written “Folsäure”.

EU law also authorises forms called methylfolate in food supplements (calcium L-methylfolate, for example; Directive 2002/46/EC). The WHO recommendation and the EU risk-reduction claim, however, concern folic acid. This guide does not present any form as “better”: if your supplement contains methylfolate, ask your doctor or pharmacist whether it suits your plans.

In 2014 the European Food Safety Authority (EFSA) set reference values for folate intake, expressed in dietary folate equivalents (DFE): a population reference intake of 330 µg DFE a day for adults, and an adequate intake of 600 µg DFE a day during pregnancy. DFE is a common unit that adds up food folate and added forms, each with its own factor; in 2022 EFSA set out how to count methylfolate in it. These values describe total intake: they are not supplement doses.

Folate-rich foods, according to ANSES: pulses (lentils, chickpeas…) and green leafy vegetables (spinach, broccoli, Brussels sprouts, lettuce…). ANSES's Ciqual food composition table gives the full list. Diet matters, but the WHO recommendation concerns a folic acid supplement: ask your doctor or midwife what suits your case.

A “trying to conceive” supplement (“Kinderwunsch” on German boxes) usually combines folic acid or another form of folate with other vitamins and minerals, for the period before pregnancy. It is a food supplement, which Directive 2002/46/EC defines as a foodstuff intended to supplement the normal diet: it is not a medicine, and it promises neither conception nor any result. Read the composition and ask for advice. See Fertility & trying to conceive, Folic acid and Pregnancy & breastfeeding vitamins.

Men are concerned too. Regulation (EU) No 432/2012 authorises these claims: “Zinc contributes to normal fertility and reproduction”, “Zinc contributes to the maintenance of normal testosterone levels in the blood” and “Selenium contributes to normal spermatogenesis”. Each may be used only for food which is at least a source of that nutrient. These sentences describe a nutrient's role; they guarantee no effect for any individual. See Zinc.

A man who has questions about his fertility should see a doctor. And if you are preparing for a pregnancy, talk to your doctor or midwife: they will tailor the advice to your situation.

Sources consulted on 7 November 2026.

1. WHO, e-Library of Evidence for Nutrition Actions (eLENA): “Periconceptional folic acid supplementation to prevent neural tube defects”, last updated 9 August 2023 (https://www.who.int/tools/elena/interventions/folate-periconceptional).

2. WHO, eLENA: “Daily iron and folic acid supplementation during pregnancy”, last updated 26 July 2024 (https://www.who.int/tools/elena/interventions/daily-iron-pregnancy).

3. European Commission, Commission Regulation (EU) No 1135/2014 of 24 October 2014 on the authorisation of a health claim made on foods and referring to the reduction of disease risk, Annex (https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32014R1135).

4. European Parliament and Council, Regulation (EC) No 1924/2006 of 20 December 2006 on nutrition and health claims made on foods, Article 14, consolidated version of 13 December 2014 (https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02006R1924-20141213).

5. European Commission, Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, Annex, consolidated version of 20 August 2025 (https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02012R0432-20250820).

6. European Parliament and Council, Directive 2002/46/EC of 10 June 2002 on food supplements, Article 2 and Annex II, consolidated version of 26 November 2025 (https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02002L0046-20251126).

7. EFSA, “Scientific Opinion on Dietary Reference Values for folate”, EFSA Journal, 2014, vol. 12, no. 11, 3893 (https://doi.org/10.2903/j.efsa.2014.3893).

8. EFSA, “Conversion of calcium-L-methylfolate and (6S)-5-methyltetrahydrofolic acid glucosamine salt into dietary folate equivalents”, EFSA Journal, 2022, vol. 20, no. 8, 7452 (https://doi.org/10.2903/j.efsa.2022.7452).

9. ANSES (French Agency for Food, Environmental and Occupational Health & Safety), “Tout savoir sur la vitamine B9” (https://www.anses.fr/fr/content/vitamine-b9-ou-acide-folique).

10. De-Regil LM, Peña-Rosas JP, Fernández-Gaxiola AC, Rayco-Solon P., “Effects and safety of periconceptional oral folate supplementation for preventing birth defects”, Cochrane Database of Systematic Reviews, 2015, issue 12, CD007950 (https://doi.org/10.1002/14651858.CD007950.pub3).