Folic acid when planning a pregnancy

Taking a folic acid supplement, also known as vitamin B9, for at least 3 months before you become pregnant is very important.

Why you need it

Folic acid helps support your baby's spine and brain development. A baby's spine develops fully during the first month of pregnancy. Folic acid helps prevent conditions known as neural tube defects (NTDs) like spina bifida.

How long to take it

Start taking folic acid at least 3 months before you become pregnant. Doctors advise that you continue to take a folic acid supplement until week 12 of your pregnancy.

Recommended amount

The recommended dose is 400 micrograms of folic acid supplement everyday. Ask your pharmacist about the best product for you.

It isn't possible to get the amount of folic acid you and your baby need from food alone. Your body will be drawing on all your nutrients when you become pregnant.

A 400 micrograms supplement and a healthy diet will help make sure you and your baby are healthy.

Neural tube defects (NTDs)

Some women may be at a higher risk of having a baby with a NTD. You are at a higher risk if:

  • you have an NTD, for example spina bifida or hydrocephalus
  • your partner's family have a history of NTDs
  • you are overweight or obese – ask your GP if you need a higher dose of folic acid
  • you have type 1 or type 2 diabetes

Folic acid can also affect certain medications you may be taking, for example for epilepsy. If you are unsure for any reason ask your GP for advice.

Related topic

Safefood: Folic acid

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.

Page last reviewed: 15 March 2018
Next review due: 15 March 2021