Comparison

Folate vs folic acid

Folate is the natural form of vitamin B9 in food; folic acid is the synthetic form used in supplements and fortified foods. Both raise your folate status, but folic acid is more stable and is the form the NHS specifies for pregnancy, advising 400 micrograms a day when trying to conceive and up to 12 weeks. This is information, not medical advice.

At a glance

Same vitamin, different forms

Folate and folic acid are two forms of the same nutrient, vitamin B9. Folate is the umbrella term for the form that occurs naturally in foods such as leafy green vegetables, pulses, and fortified breakfast cereals. Folic acid is the synthetic version used in supplements and in the flour and cereals that carry added B9. Because folic acid is chemically stable and well absorbed, it is the practical way to guarantee a specific daily amount, which is exactly what pregnancy guidance depends on.

Your body converts folic acid into the active folate it uses. A third option, methylfolate (5-MTHF), is already in that active form and is sold as an alternative, often marketed to people with variants in the MTHFR gene that affect conversion. For most people the difference in practice is small, and UK pregnancy guidance still specifies folic acid.

Bioavailability and MTHFR

Food folate is well used by the body but is fragile: it degrades with cooking, light and storage, so it is hard to rely on for a precise intake. Folic acid is more stable and predictable, which is why it is used for supplementation and fortification. The EFSA-authorised claims for folate include that supplemental folic acid increases maternal folate status, which contributes to normal neural-tube development, and that folate contributes to normal blood formation.

MTHFR gene variants can reduce how efficiently folic acid is converted, and this is the main argument made for methylfolate. The evidence that it meaningfully changes outcomes for most people is limited, so if MTHFR is a concern the sensible step is to discuss it with your GP rather than switch supplement on your own.

Pregnancy: what the NHS advises

The NHS advises taking a daily 400 microgram folic acid supplement while trying to conceive and until you are 12 weeks pregnant, to help prevent neural tube defects such as spina bifida. It specifies folic acid, and it is worth starting before conception because the neural tube forms very early. Some women, for example those with a higher risk, are advised a 5 milligram dose, which is prescription only, so ask your GP or midwife whether that applies to you.

Which should you choose?

For pregnancy and preconception, follow the NHS and choose folic acid at 400 micrograms a day unless your GP advises otherwise. Day to day outside pregnancy, a varied diet rich in folate usually covers the roughly 200 microgram reference intake without a supplement. Methylfolate is a personal choice some people make, but it is not required by UK guidance. Compare products in our roundups of the best prenatal vitamins and the best fertility supplements.

Frequently asked questions

Read more in our guides to trying to conceive, pregnancy nutrition and supplements in pregnancy and when trying to conceive. Terms like folate, neural tube defect and bioavailability are explained in our glossary.

This is information, not medical advice, and is not a substitute for a registered clinician. Always read product labels and follow current NHS guidance, and speak to your GP, midwife or pharmacist before starting a supplement in pregnancy or when trying to conceive.