Folic acid is indicated during pregnancy for the prevention of neural tube defects in the fetus. The neural tube is the structure that develops into the brain and nervous system. Examples of neural tube defects include spina bifida, myelomeningocele, anencephaly, and cleft palate.

Folic acid should ideally be started about 3 to 6 months prior to pregnancy, or at least 1 month before getting pregnant, and continued throughout the whole pregnancy. Those who are planning a pregnancy are therefore recommended to start taking folic acid.

Folic acid supports a healthy pregnancy and fetal development and should be included as part of routine prenatal care, as advised by your doctor or midwife. Taking folic acid during pregnancy does not cause weight gain.

Indications for use

Folic acid is indicated during pregnancy to lower the risk of congenital defects in the fetus, including:

Spina bifida;
Anencephaly;
Encephalocele;
Cleft lip;
Heart defects.

It is important to start taking folic acid in the preconception period (prior to getting pregnant), as the neural tube closes by 28 days following conception, a period during which many people do not even know they are pregnant. After this period, folic acid supplementation will have no effect on preventing neural tube defects.

Folic acid should be continued throughout pregnancy, however, as it helps in placental formation, DNA and cell synthesis, and fetal cardiac (heart) formation. It also decreases the risk of other pregnancy complications such as anemia in the mother, preeclampsia, and preterm birth.

How to take

The typical recommended dose of folic acid during pregnancy is 400 to 800 mcg per day prior to getting pregnant and during the first three months of pregnancy.

Higher doses of folic acid may be recommended for those at high risk of folic acid deficiency and doses may vary based on the needs of the individual. People with a higher risk of folic acid deficiency include people with obesity, epilepsy (seizures), and a history of having a child with a nervous system disorder.

Folic acid is found in most prenatal vitamins. Be sure to check with your doctor or midwife to see if you need to take extra folic acid in addition to what is found in your prenatal vitamin.

Folic acid should be continued throughout pregnancy and may be combined with iron supplementation to prevent maternal anemia, fetal iron deficiency, and low birthweight. Learn more about iron supplements (including ferrous sulfate) and iron-rich foods.

Food sources

In addition to taking supplements, folic acid can be found in certain foods, including:

Liver (chicken or turkey, for example);
Brewer's yeast;
Black beans;
Spinach;
Pasta;
Peas and lentils.

Eating these foods regularly can help guarantee adequate intake of folic acid and support fetal development.

Side effects

Folic acid is typically well tolerated. Side effects are more commonly seen in people taking higher doses than recommended, and may include constipation, gas and bloating, stomach pain, nausea, vomiting, bitter taste in the mouth, difficulty concentrating, difficulty sleeping, irritability, depression, allergic reactions, and difficulty breathing. It is important to talk to your doctor or midwife about any side effects you may be experiencing and to seek urgent medical attention for serious side effects such as worsening depression, allergic reactions, or difficulty breathing.