Pregnancy

Folate and folic acid in pregnancy: how much, and which form

Written by the NATURELO nutrition teamReviewed by Milan ShahLast reviewed 26 September 20263 min read

The short answer

Take 400 micrograms of folic acid a day from before you conceive until you are 12 weeks pregnant. Of all the supplement steps in early pregnancy, this one has the strongest evidence behind it: at that intake, folic acid raises maternal folate status, and low maternal folate status is a risk factor for neural tube defects such as spina bifida. Folate, folic acid and methylfolate are three forms of the same B vitamin. The strong evidence is on folic acid, so that is the form named in the official recommendation, whichever form your prenatal uses.

  • 400 µg folic acid daily, from before conception to 12 weeks.
  • Some women need a higher 5 mg dose, on a GP's prescription.
  • The recognised benefit is on folic acid.
  • Methylfolate is the active form some prefer, but folic acid is the studied one.
Leafy greens, broccoli, beans and avocado on a table

Folate, folic acid and methylfolate

These are three names for the same vitamin. Folate is the natural form in foods like leafy greens and pulses. Folic acid is the synthetic form used in supplements and fortified flour, and it is the form used in the research. Methylfolate, or 5-MTHF, is the already-active form your body would otherwise convert folic acid into. For general health, any of them works. In pregnancy the difference matters, because the recommendation is specific about both the form and the amount.

How much, and for how long

The NHS advice is 400 micrograms of folic acid a day, from before you conceive until the end of week 12. The recognised benefit comes at that intake, taken from at least one month before conception through the first trimester: folic acid raises maternal folate status, and low maternal folate status is a risk factor in the development of neural tube defects in the developing foetus. The baby's neural tube forms in the first few weeks, often before a pregnancy is confirmed, so the ideal is to start when you begin trying. If your pregnancy was not planned, start as soon as you find out.

Who needs the higher 5 mg dose

Some women are advised to take a much higher dose, 5 milligrams a day, which is a prescription rather than an off-the-shelf product. This is for higher-risk pregnancies: a previous pregnancy affected by a neural tube defect, diabetes, a high BMI, certain medicines, or conditions like sickle cell. That higher dose is decided by your GP or midwife. If any of that might apply to you, ask them.

Methylfolate: what it is, and how to think about it

You will see prenatals, ours included, that use methylfolate rather than folic acid. Methylfolate is the active form, so there is no conversion step, and some women prefer it, especially if they have heard about the MTHFR gene. Methylfolate is a legitimate source of folate. For neural tube defects, though, the studied form is folic acid: the evidence base was built on it. So if following the NHS recommendation exactly matters to you, a 400 microgram folic acid supplement is the studied choice. If you are happy with the active form at an appropriate amount, a methylfolate prenatal provides folate alongside the other nutrients of pregnancy. In both cases it comes down to the amount and the timing, and your midwife can confirm your plan.

What our prenatal uses

Our prenatal provides folate as L-5-methylfolate, the active form, at 800 micrograms, alongside iron, iodine, vitamin D and DHA, so the pregnancy essentials sit in one capsule. If you would prefer to take folic acid in the exact form the NHS studied, you can pair a simple 400 microgram folic acid with the rest of your routine. Both are valid, so choose the one that fits how closely you want to follow the advice.

FAQ

Questions people ask

How much folic acid should I take in pregnancy?

400 micrograms a day, from before conception until 12 weeks. Some women need a prescribed 5 mg dose.

Is methylfolate better than folic acid in pregnancy?

It is the active form, but the authorised claim linked to neural tube defects is for supplemental folic acid. Neither is "better" without that context.

What if I did not take folic acid before I knew I was pregnant?

Start as soon as you find out, and mention it to your midwife. It is common, and the advice is simply to begin now.

When do I stop taking folic acid?

At the end of week 12, unless your midwife or GP advises otherwise.

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The NATURELO nutrition team

Reviewed by Milan Shah, Certificate in Plant-Based Nutrition, T. Colin Campbell Center for Nutrition Studies (eCornell).

This guide is general information, not a substitute for advice from your GP, midwife or pharmacist.