Folic acid, sometimes called folate, is a vitamin that belongs to the vitamin B group. Your body needs folic acid when cells are growing and dividing very quickly, which happens during pregnancy.
What are folate and folic acid?
Folate is an essential B vitamin. It is found in leafy vegetables, citrus fruits, wholemeal bread, yeast, liver and legumes.
Folic acid is the synthetic (‘man made’) form of folate. Folic acid is used in dietary supplements and fortified foods and drinks. It is more easily absorbed and used in your body, and more stable, than folate found in food.
What are the benefits of folic acid in pregnancy?
Early in pregnancy, when the foetus is developing, folic acid plays an important role in the development of the neural tube. As the foetus grows, the neural tube develops into the brain and spinal cord.
Sometimes an abnormality occurs when the neural tube does not close properly. This causes conditions known as neural tube defects (NTDs).
- Neural tube defects happens in about 1 in 500 babies.
- Some examples of neural tube defects are spina bifida, where the spine or its covering sticks out of the back, and anencephaly, in which the brain does not form properly.
- Babies born with these defects often die, or have problems with walking and bowel and bladder control. Read more about neural tube defects.
Research shows that women who have a high level of folic acid before they become pregnant are less likely to give birth to a baby with NTDs. Folic acid supplementation can prevent up to 70 per cent of these defects.
How much folic acid should I take?
During your pregnancy, you should eat plenty of the foods that have folate in them, such as leafy green vegetables, wholegrain breads and cereals. However, you will not get enough folate from food to prevent NTDs.
The only way to be sure you're getting the right amount of folic acid is by taking a supplement. It's recommended that all women who are planning a pregnancy should take a daily supplement of folic acid. Folic acid is available in tablet form.
It's best to start taking folic acid before conception and continue until week 12 of pregnancy. Your baby's spine develops during this first trimester.
If the pregnancy is unplanned, start taking folic acid as soon as you know you are pregnant. For women who do not have high risk factors, the usual dose of folic acid for the prevention of NTDs is 800 micrograms once a day. Read more about folic acid tablets.
Some women are at increased risk of having a baby with a spinal cord problem. These women need higher doses of folic acid – 5 milligrams once a day.
You are at higher risk if:
- you have had a previous pregnancy affected by a neural tube defect
- you or your partner have a spinal cord defect
- your or your partner have family members with a spinal cord defect
- you are taking medication that is known to affect folate metabolism, such as medicine for epilepsy (eg, carbamazepine, sodium valproate)
- you are on insulin treatment for diabetes
- you are obese, that is, if your body mass index (BMI) is 30 or more
- you have coeliac disease, diabetes, sickle cell anemia or thalassaemia.
If you are planning to get pregnant, be sure to get enough folate to reduce the risk of these serious conditions for your baby.
Planning for pregnancy or when pregnant Ministry of Health, NZ
Folate/folic acid – questions and answers Ministry of Health, NZ
Food and nutrition guidelines for healthy pregnant and breastfeeding women in NZ Ministry of Health, NZ
- The role of the primary healthcare team in pregnancy care BPAC, NZ, 2019
- Cavalli P. Prevention of Neural Tube Defects and proper folate periconceptional supplementation J Prenat Med. 2008;2(4):40–41.
- Folate/folic acid Ministry of Health, NZ, 2019