Pregnancy Supplements: Folic acid

Folic acid is one of the few supplements routinely recommended around the start of pregnancy in the UK. The NHS recommends taking 400 micrograms every day while trying for a baby and during the first 12 weeks of pregnancy. Ideally, it is started before conception, but if you are already pregnant and have not been taking it, NHS guidance says to start as soon as you find out.

Some people need a higher prescribed dose because of their medical history, medicines or other factors. That decision should be made with a GP or another healthcare professional rather than by increasing the dose yourself.

What is folic acid?

Folic acid is the manufactured form of folate, a B vitamin found naturally in some foods.

Folate is needed for healthy cell growth and development. During the earliest stages of pregnancy, it has a particularly important role as the baby’s brain and spinal cord begin to develop.

Food sources of folate include green leafy vegetables and some fortified foods. However, NHS guidance still recommends a folic acid supplement around conception and in early pregnancy because it can be difficult to get the recommended amount from food alone.

Why is folic acid recommended in pregnancy?

The main reason for taking folic acid before and during early pregnancy is to reduce the chance of neural tube defects.

Neural tube defects affect the developing brain and spinal cord. Spina bifida is one example.

The neural tube develops very early in pregnancy, which is why the recommendation begins before conception rather than after the first antenatal appointment.

Taking folic acid cannot guarantee a particular pregnancy outcome, but it is an established part of UK preconception and early pregnancy guidance.

When should you start taking folic acid?

The NHS recommends taking 400 micrograms of folic acid every day before becoming pregnant and continuing until you are 12 weeks pregnant.

Ideally, you should start taking it three months before you begin trying for a baby.

Of course, pregnancy is not always planned and not everyone knows they are pregnant straight away. If you find out that you are pregnant and have not been taking folic acid, the NHS advises starting it as soon as you find out.

There is no benefit in feeling guilty about not having started earlier. The practical next step is to follow current guidance from the point you know you are pregnant and speak to your midwife or GP if you have questions.

For most people who are trying to conceive or are in the first 12 weeks of pregnancy, NHS guidance recommends 400 micrograms of folic acid each day.

This is the standard recommendation, but it does not apply to everyone.

Some people have a higher chance of a pregnancy affected by a neural tube defect and may be advised to take a higher dose. Higher-dose folic acid is prescribed rather than simply chosen from the supplement aisle.

If you think any higher-risk factors may apply to you, speak to a GP before trying to conceive where possible, or as soon as you can during pregnancy.

Who may need a higher dose of folic acid?

The NHS advises that some people may need a higher dose of folic acid, usually 5 milligrams, prescribed by a GP.

This can apply if you or the baby’s biological parent have a neural tube defect, if either of you has a family history of neural tube defects, or if you have previously had a pregnancy affected by one.

A higher dose may also be recommended in some other circumstances, including certain medical conditions and medicines.

NICE advises healthcare professionals to consider higher-dose folic acid for people with particular risk factors. It also gives specific guidance for people taking certain medicines, including some anti-epileptic medicines, and for those with conditions such as diabetes.

Do not decide to take a higher dose based only on a checklist online. Your GP can assess your individual circumstances and prescribe the appropriate amount if needed.

What if you have had bariatric surgery?

Previous bariatric surgery can affect how nutrients are absorbed.

NICE advises people who have had bariatric surgery and are planning a pregnancy, or who are already pregnant, to contact their bariatric surgery unit for individual advice about folic acid and other micronutrient supplements.

This is an area where personalised guidance matters because needs can vary depending on the type of surgery and individual nutritional status.

Can you get enough folate from food?

Folate occurs naturally in foods including leafy green vegetables, broccoli, Brussels sprouts, peas and chickpeas. Some breakfast cereals and other foods are also fortified with folic acid.

Eating a varied diet can contribute useful folate, but the NHS recommends a folic acid supplement even if your diet includes folate-rich foods.

This is because it is difficult to get the amount recommended for pregnancy from food alone.

You do not need to create a perfect pregnancy diet around folate. Think of food and the recommended supplement as separate parts of looking after your nutritional needs.

Is folic acid included in pregnancy multivitamins?

Many pregnancy multivitamins contain folic acid, but formulations vary.

Check the label to see how much the product contains rather than assuming every prenatal supplement is the same. If you are combining a multivitamin with a separate folic acid supplement, ask a pharmacist or your maternity team if you are unsure whether you are duplicating ingredients.

If you choose a pregnancy multivitamin, the NHS advises checking that it does not contain vitamin A in the form of retinol, which should be avoided during pregnancy.

People who have been prescribed higher-dose folic acid should follow the instructions given by their healthcare professional rather than trying to recreate that dose with several over-the-counter supplements.

What if folic acid makes you feel unwell?

Some people may experience side effects from folic acid. The NHS lists feeling sick, loss of appetite and bloating or wind among possible common side effects.

If you are struggling to take your supplement or think it is causing side effects, speak to a pharmacist, GP or midwife. They can help you work out what is appropriate without simply stopping something that has been recommended for pregnancy.

Seek medical help if you develop symptoms of a serious allergic reaction after taking any medicine or supplement.

Do you need folic acid after 12 weeks?

The routine NHS recommendation specifically covers the period before pregnancy and the first 12 weeks.

There may be individual reasons why a healthcare professional advises you to continue taking folic acid later in pregnancy. For example, folic acid may sometimes be used as part of treatment for folate deficiency anaemia.

If you are taking folic acid for another medical reason, do not stop or change it based on general pregnancy guidance. Ask the clinician responsible for your care.

When to get professional advice

Speak to your GP, midwife or pharmacist if you are pregnant and unsure whether you are taking the right folic acid supplement, particularly if you take regular medicines or have a long-term health condition.

Contact your GP if you think you may need a higher prescribed dose because of your medical history, family history, previous pregnancy, medicines or another risk factor. If possible, have this conversation before conception, but ask for advice promptly if you are already pregnant.

If you have had bariatric surgery, NICE recommends contacting your bariatric surgery unit for individual advice about folic acid and other micronutrients.

If you have missed folic acid before discovering your pregnancy, NHS guidance is to start taking it as soon as you find out you are pregnant. Your midwife or GP can answer any concerns about your individual situation.

For possible side effects or questions about a supplement, a pharmacist can also advise. If you develop symptoms of a severe allergic reaction, seek emergency medical help.