Folic acid | March of Dimes

What is folic acid?

Folic acid is B vitamin that every cell in your body needs for normal growth and development. It helps your body make red blood cells that carry oxygen from your lungs to all parts of your body. 

If you take folic acid before and during early pregnancy, it can help prevent birth defects of the brain and spine called neural tube defects (also called NTDs). Some studies show that it also may help prevent heart defects in a baby and birth defects in a baby’s mouth called cleft lip and palate

Why is it important to take folic acid before pregnancy?

Taking folic acid before pregnancy can help prevent NTDs in your baby. The neural tube is the part of a developing baby that becomes the brain and spinal cord. NTDs happen in the first month of pregnancy, before you may know that you’re pregnant. This is why it’s important that you have enough folic acid in your body before you get pregnant. 

Because nearly half of all pregnancies in the United States are unplanned, all women should take folic acid every day. Take a multivitamin with 400 mcg of folic acid every day, even if you’re not trying to get pregnant. 

NTDs affect about 3,000 pregnancies each year in the United States. If all women take 400 mcg of folic acid every day before getting pregnant and during early pregnancy, it may help prevent up to 7 in 10 (70 percent) NTDs. 

How can you get folic acid? 

Before pregnancy, take a multivitamin that has 400 mcg of folic acid in it every day. Most multivitamins have this amount, but check the label to be sure. 

During pregnancy, take a prenatal vitamin each day that has 600 mcg of folic acid in it. You need more folic acid during pregnancy to help your baby grow and develop. Your health care provider can prescribe a prenatal vitamin for you. Or you can get prenatal vitamins over the counter without a prescription. 

You also can get folic acid from food. Some foods have folic acid added to them. Look for the word “fortified” or “enriched” on the package label on foods like:

  • Bread
  • Breakfast cereal
  • Cornmeal
  • Flour
  • Pasta
  • Products made from a kind of flour called corn masa, like tortillas, tortilla chips, taco shells, tamales and pupusas
  • White rice

Some fruits and vegetables are good sources of folic acid. When folic acid is naturally in a food, it’s called folate. Foods that are good sources of folate are:

  • Beans, like lentils, pinto beans and black beans
  • Leafy green vegetables, like spinach and Romaine lettuce
  • Asparagus 
  • Broccoli
  • Peanuts (But don’t eat them if you have a peanut allergy.) 
  • Citrus fruits, like oranges and grapefruit
  • Orange juice (100 percent juice is best. This means one serving of juice is equal to one serving of fruit.)

It’s hard to get all the folic acid you need from food. Even if you eat foods that have folic acid in them, take your multivitamin each day, too.

How do you read a product label to see how much folic acid is in a multivitamin?

To find out if a multivitamin has folic acid in it, check the label (also called supplement facts)! You usually can find it on the back of the bottle. Look for the word “folate” on the label to see how much folic acid you’re getting. The label tells you this information:

  • Serving size. This tells you how much of the product is in one serving. One multivitamin usually is one serving. 
  • Servings per container. This tells you how many servings are in a multivitamin bottle. For example, if two pills is one serving and the bottle has 30 multivitamins in it, that’s 15 servings. 
  • Nutrients, like vitamin D, folate and calcium, in each serving
  • Daily value (also called DV) of one serving. DV is the amount of a nutrient in a serving. For example, if the DV of folic acid in a multivitamin is 50 percent, that multivitamin gives you 50 percent (half) of the folic acid you need each day. 

Labels on food products don’t always list the amount of folic acid in the product. New food labels that list folic acid will list mcg DFE of folate, just like for multivitamins. 

If you have an MTHFR variant, can taking folic acid help prevent NTDs in your baby?

Yes. If you have an MTHFR variant, taking 400 mcg of folic acid every day before and during early pregnancy can help prevent NTDs in your baby.

MTHFR stands for methylenetetrahydrofolate reductase. It’s an enzyme (protein) that helps your body break down and use folate. One MTHFR variant (called MTHFRTT or CT genotype) is a change in your body’s MTHFR gene that makes you use folate more slowly than usual. Genes are parts of your body’s cells that store instructions for how your body grows and works. MTHFR variants are inherited (passed from parents to children) through genes. If you know you have an MTHFR variant or you think it runs in your family, talk to your provider.

Your provider may want to test you for an MTHFR variant if you have high levels of a substance in your blood called homocysteine. Too much homocysteine in your blood can cause heart conditions, blood clots and stroke. You can find out your homocysteine levels with a blood test. If your level is high, you can have a genetic test (test that checks your genes) to see if you have an MTHFR variant.

You may have heard not to take folic acid if you have an MTHFR variant because it can increase your risk of pregnancy complications and your baby having health problems. The Centers for Disease Control and Prevention (also called CDC) recommends that all women take 400 mcg of folic acid every day before and during early pregnancy. If you have an MTHFR variant, talk to your provider.

Do some women need extra folic acid?

Yes. Most women don’t need more than 1,000 mcg of folic acid each day, but some may need more. Talk to your provider to make sure you take the right amount. You may need extra folic acid before and during pregnancy if:

  • You’ve had a pregnancy affected by an NTD in the past.
  • You have diabetes. This is a medical condition in which your body has too much sugar (called glucose) in your blood.
  • You’re obese. This means you have an excess amount of body fat and your body mass index (also called BMI) is 30 or higher. To find out your BMI, go to www.cdc.gov/bmi.
  • You have a hemoglobin disorder, like sickle cell disease. Hemoglobin disorders are rare blood conditions that are caused by problems with hemoglobin. Hemoglobin is a protein in the blood that carries oxygen. 
  • You take antiseizure medicine.

More information

Last reviewed: April, 2017