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Folic acid is the synthetic form of folate, which is a naturally occurring B vitamin. Folate helps make DNA and other genetic material. It is especially important in prenatal health.

Folate, also called vitamin B-9, is a B vitamin that naturally occurs in certain foods. Folic acid is the form of folate that manufacturers add to vitamin supplements and fortified foods.

This article explores the functions of folic acid in the body, some sources, the recommended intakes, and the effects of deficiency.

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Folic acid may reduce the risk of preterm birth.

Folate is important for a range of functions in the body.

It helps the body make healthy new red blood cells, for example. Red blood cells carry oxygen throughout the body. If the body does not make enough of these, a person can develop anemia, leading to fatigue, weakness, and a pale complexion.

Without enough folate, a person can also develop a type of anemia called folate deficiency anemia.

Folate is also important for the synthesis and repair of DNA and other genetic material, and it is necessary for cells to divide.

It is particularly important to get enough folate during pregnancy. Folate deficiency during pregnancy can lead to neural tube irregularities, such as spina bifida and anencephaly.

Because of its importance for health, the Food and Drug Administration (FDA) require manufacturers to add folic acid to enriched bread, pasta, rice, cereals, and other grain products in the United States. Since they introduced this, the number of babies born with neural tube irregularities has decreased.

The following list looks at some conditions that folic acid supplements could have an impact on:

Neural tube irregularities

Taking folic acid supplements before and during pregnancy will help prevent neural tube irregularities in the fetus.

It may also reduce the risks of preterm birth, heart irregularities, and cleft palate, among other things.

The Office of Dietary Supplements say that all women who could soon become pregnant should take 400 micrograms (mcg) of folic acid daily — from supplements or fortified foods — alongside the folate they get from their regular diet.


People with lower levels of folate may be more likely to experience depression. However, taking folic acid supplements could make depression medications more effective.


Some research suggests that taking folic acid before and during early pregnancy could reduce the chance that the baby will have autism. However, the study results are not conclusive, and more research will be necessary to determine the potential role of folic acid.

Rheumatoid arthritis

Doctors may use folic acid to support a methotrexate prescription for rheumatoid arthritis.

Methotrexate is an effective medication for this condition, but it may remove folate from the body, causing gastrointestinal symptoms. Studies suggest that taking folic acid supplements could reduce these side effects by around 79%.

Most people get enough folate from their diet, and folate deficiency is rare in the United States.

That being said, official guidelines recommend that all pregnant women and women who might become pregnant take folic acid.

This is because folic acid is crucial for early fetal development. The spinal cord is one of the first parts of the body to form, and folate deficiency can lead to spinal cord irregularities.

The Office on Women’s Health recommend that women who are or might become pregnant take 400–800 mcg of folic acid per day, and that people with spina bifida or a family history of neural tube irregularities take 4,000 mcg per day. Those who are breastfeeding should aim to take around 500 mcg per day.

The body absorbs folic acid from supplements and fortified foods better than the folate from naturally occurring foods.

The Office of Dietary Supplements recommend that people get the following dietary folate equivalents (DFEs) from food or vitamin sources:

AgeRecommended amount
0–6 months65 mcg DFE
7–12 months80 mcg DFE
1–3 years150 mcg DFE
4–8 years200 mcg DFE
9–13 years300 mcg DFE
14–18 years400 mcg DFE
19+ years400 mcg DFE

It is important to note that folic acid can interact with certain medications and may not be safe for everyone to take.

A person should speak to a doctor before taking folic acid if they have any of the following:

  • epilepsy
  • type 2 diabetes
  • rheumatoid arthritis
  • lupus
  • inflammatory bowel disease (IBD)
  • celiac disease

People undergoing kidney dialysis may also wish to avoid taking folic acid.

Folic acid is present in dietary supplements and fortified foods, including breads, flours, cereals, and grains. It is also a common addition to B-complex vitamins.

Many foods are naturally high in folate. The best sources include:

  • beef liver
  • boiled spinach
  • black-eyed peas
  • asparagus
  • Brussels sprouts
  • lettuce
  • avocado
  • broccoli
  • mustard greens
  • green peas
  • kidney beans
  • canned tomato juice
  • Dungeness crab
  • orange juice
  • dry-roasted peanuts
  • fresh orange and grapefruit
  • papaya
  • banana
  • hard-boiled egg
  • cantaloupe

Folate deficiency occurs when there is not enough folate present in the body. This can lead to a type of anemia called megaloblastic anemia.

During pregnancy, folate deficiency increases the risk of congenital irregularities.

Some symptoms of folate deficiency include:

  • weakness
  • fatigue
  • trouble concentrating
  • headache
  • irritability
  • heart palpitations
  • sores on the tongue and inside the mouth
  • a change in color of the skin, hair, or fingernails
  • irritability, headache, heart palpitations, and shortness of breath

Some groups at increased risk of folate deficiency include:

  • people with alcohol use disorder
  • pregnant women
  • people of childbearing age
  • people with conditions that affect nutrient absorption, including IBD and celiac disease
  • people with MTHFR polymorphism

There are no serious side effects associated with taking too much folic acid. In very rare cases, people may report an upset stomach.

If a person takes more folate than necessary, there is no cause for concern. Folic acid is water soluble, so any excess will naturally pass through the urine.

Folic acid is the synthetic form of folate, an important B vitamin. Most people get enough folate from their diet, but people at risk of deficiency and women who may become pregnant may need to take folic acid supplements.

Folic acid supplements are available to purchase online.