Folate (Folic Acid)

Medically Reviewed by Zilpah Sheikh, MD on September 05, 2023
6 min read

Folate, also known as vitamin B9, is the generic term for the vitamin that occurs naturally in certain foods. Folic acid is the lab-made form of the vitamin and is used in dietary supplements and added to foods. Folic acid from enriched foods and supplements is absorbed better by our bodies than from natural food sources.

Folate and folic acid are important for cell growth and metabolism. Studies show that certain groups of people in the U.S., including Black women and women of childbearing age, don't get enough folic acid.

Folic acid supplements are standard for women who are or may become pregnant. Folic acid may reduce the risk for birth defects of a baby’s brain and spine (spina bifida and anencephaly) by 70% or more. Folic acid may also lower the risk of preeclampsia and early labor.

If you are a woman of childbearing age, many doctors will recommend you take either a multivitamin or a folic acid supplement. Folic acid can protect against birth defects that may form before you know you are pregnant.

Folic acid is used to treat deficiencies, which can cause certain types of anemia and other problems. Certain conditions, such as alcoholism, kidney or liver disease, and digestive problems, can put you at greater risk of not getting enough folate. Folic acid is also used to reduce the toxicity of the drug methotrexate in people with psoriasis and rheumatoid arthritis.

Folic acid supplements have been studied as treatments for many other conditions, including autism spectrum disorder in children and hearing loss and macular degeneration related to age. We need more research to confirm the effectiveness of folic acid for these conditions.

Why you need folate

The daily recommended intake of folate for teens and adults is 400 mcg. Pregnant women need at least 600 mcg per day, and breastfeeding women need 500 mcg.

Too little of the vitamin can lead to megaloblastic anemia, which has symptoms such as:

Additional signs of folate deficiency include shortness of breath, irregular heartbeat, difficulty focusing, and fatigue.

Heart health. Both folate and vitamin B12 play an essential role in changing homocysteine, an amino acid in your blood, into methionine, which is one of the essential building blocks of new proteins. Without enough folate, the process doesn't work, which leads to increased levels of homocysteine in the blood and an increased risk of heart disease.

Reduced cancer risk. High homocysteine levels and low folate levels are also associated with an increased risk of cancer. However, taking high amounts of folate after a cancer diagnosis may speed up the progression of the disease. If you have cancer, speak with your doctor before taking folic acid supplements.

Brain health. Too little folate could lead to an increased risk of depression. People with depression and low folate levels may also not respond as well to antidepressants as people with adequate levels of the vitamin in their blood. Some studies show that increasing folate (or taking a folic acid supplement) in addition to an antidepressant may help increase the effectiveness of the medication.

The recommended dietary allowance (RDA) includes the folate you get from both the food you eat and any supplements you take.

Folate (Folic Acid) Recommended Dietary Allowance (RDA)
For children under 1, only an adequate intake (AI) is available
0-6 months65 mcg/day
Adequate Intake (AI)
7-12 months80 mcg/day
Adequate Intake (AI)
1-3 years150 mcg/day
4-8 years200 mcg/day
9-13 years300 mcg/day
14 years and older400 mcg/day
Pregnant teens and women600 mcg/day
Breastfeeding teens and women500  mcg/day

The tolerable upper intake level (UL) of a supplement is the highest amount that most people can take safely. Higher doses might be used to treat folate deficiencies. But don't take more unless a doctor says so.

(Children & Adults)
Folate (Folic Acid)
Tolerable Upper Intake Levels (UL)
0-6 monthsN/A (should only come from breast milk, infant formula, and food)
7-12 monthsN/A (should only come from breast milk, infant formula, and food)
1-3 years300 mcg/day
4-8 years400 mcg/day
9-13 years600 mcg/day
14-18 years800 mcg/day
19 years and older1,000 mcg/day

Many foods make it easy to get all of the vitamin B9 you need from your diet. Some of the foods richest in folate include:

1. Beef liver

Most meats are low in folate. Beef liver, however, is one of the most concentrated sources available. In addition to providing 215 mcg of folate per 3-ounce serving, beef liver also provides a decent amount of protein and more than 100% of your recommended daily intake of vitamin A, vitamin B12, and copper.

2. Dark, leafy greens

Many types of dark, leafy greens have high concentrations of folate. Spinach, a powerhouse of nutrients, provides 58 mcg of folate in a 1-cup serving of raw leaves and 131 mcg in a half-cup serving of boiled spinach. A half-cup of boiled mustard greens has 52 mcg, and a cup of cooked collards has about 136 mcg.

3. Legumes

Legumes, which include beans, peas, and lentils, are an excellent source of plant protein, as well as fiber, iron, magnesium, and antioxidants. They’re also high in folate. A half-cup of kidney beans has 46 mcg, and the same serving of black-eyed peas has 105 mcg. A half-cup of peas has 47 mcg.

4. Asparagus

Asparagus is high in many important nutrients, including folate. Four spears have 89 mcg. The vegetable also has anti-inflammatory and antibacterial properties.

5. Broccoli

Like many other vegetables, broccoli is high in many essential vitamins and minerals, such as vitamin C, vitamin K, and vitamin A. A half-cup serving of cooked broccoli provides 52 mcg.

6. Oranges

Oranges and other citrus fruits, such as lemons, are most well-known for their vitamin C content. They also contain a good amount of folate, with one small fresh orange providing 29 mcg.

7. Bananas

Bananas are known best for their potassium content. They’re high in carbohydrates and are easy to digest and take with you on the go. They’re also a perfect pre-workout snack. One medium banana contains 24 mcg of folate.

8. Eggs

Eggs are high in many essential vitamins and minerals. Along with protein, selenium, riboflavin, and vitamin B12, one hard-boiled egg contains 22 mcg of folate. While eggs are generally considered healthy, the yolks are high in cholesterol. If you have high cholesterol or heart disease, or you’re trying to watch your cholesterol intake, you may want to limit the number of eggs you eat per week.

9. Fortified and enriched products

Folate (in the form of folic acid) is added to many foods, including breads, juices, and cereals. One slice of white bread has 50 mcg of folate. Cereals that are fortified with 25% of the daily value of folate provide 100 mcg. A serving of three-fourths of a cup of tomato or orange juice contains about 36 mcg of folate.

  • Side effects. Folic acid is generally regarded as safe. Side effects are rare. High doses of folic acid can cause nausea, bloating, gas, and insomnia.
  • Interactions. High doses of folic acid can block the effects of some seizure medicines. Taking folate could interfere with methotrexate when used in people with cancer. 

    If you have ulcerative colitis, certain treatment medications can affect the amount of folate your body takes in and could create a folate deficiency. 

    If you take any regular medicines, ask your doctor how they will affect your intake of folic acid.

  • Risks. Folic acid supplementation can sometimes mask the neurologic symptoms of serious and dangerous deficiencies of vitamin B12.