Folic acid for pregnancy

What is folic acid?

Folic acid is a form of vitamin B9, also known as folate. When the nutrient comes directly from food sources, it's called folate. When it's manufactured for use as a supplement or to fortify foods, it's called folic acid.

This vitamin helps prevent certain birth defects. Essential for the production, repair, and functioning of DNA – our genetic map and a basic building block of cells – it's crucial to the rapid cell growth of the placenta and your developing baby. Your body also needs folic acid to make normal red blood cells and prevent a type of anemia (folate-deficiency anemia).

Why do I need folic acid during pregnancy?

If you're pregnant or might become pregnant, it's critically important to get enough folic acid because it helps prevent neural tube defects (NTDs), such as spina bifida (which affects the spinal cord) and anencephaly (which affects the brain). Your baby's spine and brain develop from the neural tube.

Neural tube defects occur in the earliest weeks of pregnancy – before many women even know they're pregnant. That's why it's important to begin taking folic acid before you start trying to conceive.

According to the Centers for Disease Control (CDC), NTDs affect about 3,000 pregnancies a year in the United States. But women who take the recommended daily dose of folic acid starting at least one month before conception and during the first trimester of pregnancy can reduce their baby's risk of neural tube defects by up to 70 percent.

In addition to greatly reducing the risk of NTDs, getting enough folic acid may decrease the risk of:

• Cleft lip and cleft palate
• Certain types of congenital heart defects
• Gestational diabetes
• Preterm birth

How much folic acid do I need for pregnancy?

You need 600 mcg of folic acid during pregnancy. And it can be hard to get all the folic acid you need from food alone, so you'll want to take a supplement.

In addition to eating food rich in folate (see below), experts – including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists – recommend that all women of childbearing age take a supplement containing 400 micrograms (mcg) of folic acid a day. Starting your supplement at least a month before you start trying to conceive and continuing throughout your pregnancy is ideal. But because almost half of pregnancies in the United States are unplanned, it's a good idea for all women who might become pregnant to take folic acid.

Some groups, such as the March of Dimes and the National Institutes of Health (NIH), recommend increasing your daily supplementation to 600 mcg once you become pregnant and throughout your pregnancy. The NIH also recommends taking 500 mcg of folic acid daily for as long as you're breastfeeding.

Every woman is different, so ask your healthcare provider how much folic acid is right for you. Check the label of your prenatal vitamin to see how much folic acid it contains. If it's not enough, you can switch brands or take a separate folic acid supplement. (But don't take more than one prenatal vitamin or multivitamin a day.)

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If you're taking prescription prenatal vitamins, they probably contain 800 to 1,000 mcg of folic acid. Again, check the label.

Don't take more than 1,000 mcg per day of folic acid unless your healthcare provider advises you to. This is the upper limit set by the Food and Nutrition Board at the National Academies of Sciences.

Do I need extra folic acid?

Some women need to take more than the recommended amount of folic acid. Talk with your healthcare provider about your folic acid needs if any of the following apply to you:

• You've previously been pregnant with a baby with a neural tube defect (NTD), you or your partner has an NTD, or your partner has a child with an NTD. In any of these cases, you'll probably be advised to take 4,000 mcg of folic acid daily for at least 3 months before pregnancy and for the first 3 months of pregnancy. Talk with your provider about how much to take after that. You may be able to cut back to 400 mcg beginning at 4 months.
• You're carrying twins. Your healthcare provider may recommend you take as much as 1,000 mcg of folic acid per day if you're pregnant with multiples.
• You're diabetic or are taking certain antiseizure medications. These increase your risk of having a baby with an NTD, so see your provider at least a month before trying to conceive to find out how much folic acid you should be taking and to monitor your condition in general.
• You have celiac disease, inflammatory bowel disease (IBD), or a digestive disorder. These conditions may make it harder to absorb folate.
• You have a certain genetic mutation. The research is mixed, but some studies suggest that people with a genetic variation known as a methylenetetrahydrofolate reductase (MTHFR) mutation may have an increased risk of giving birth to a baby with NTDs because this mutation may make it more difficult to process folate and folic acid.

Does folic acid cause side effects?

Most people don't have any side effects when taking folic acid at doses of less than 1,000 mcg a day. Consuming a lot of folate in your diet doesn't appear to cause problems either.

However, taking high doses of folic acid over long periods of time may cause symptoms such as:

• Abdominal cramps
• Diarrhea
• Nausea
• Gas
• Sleep problems
• Irritability
• Confusion

In rare cases, folic acid may cause an allergic reaction. Call your provider right away if you experience a skin rash, itching, or redness. As with any allergic reaction, call 911 if you have difficulty breathing.

Folic acid foods for pregnancy

Food manufacturers are required by the U.S. Food and Drug Administration to add folic acid to enriched grain products, such as breakfast cereals, bread, pasta, and rice. Some fortified breakfast cereals contain 100 percent of the recommended daily amount.

This is meant to be helpful for women who don't take a supplement and aren't planning to get pregnant. In the United States, the CDC estimates that 1,300 babies are born healthy each year because of folic acid fortification of foods. Still, most women don't eat these foods consistently enough to rely on them as a source of folic acid.

Even if you eat a complete serving of a fully fortified cereal every day, you can't be sure you're getting what you need. (For one thing, synthetic nutrients added to cereals tend to end up in the milk at the bottom of the bowl.)

Foods that are naturally rich in folate aren't a great source either. Oddly enough, research shows that the body absorbs folic acid from supplements much better than the folate that occurs naturally in certain foods. What's more, folate can be lost from foods during storage or destroyed by cooking.

So if you eat foods rich in folate, consider them a complement to your supplement. Good sources include:

• Lentils
• Dried beans, peas, and nuts
• Avocado
• Dark green vegetables such as broccoli, spinach, collard or turnip greens, okra, Brussels sprouts, and asparagus
• Citrus fruit and juice
• Tomato juice
• Bananas
• Eggs
• Squash (winter and summer varieties)
• Wheat germ
• Cornmeal
• Corn masa (found in tortillas, taco shells, and tamales)
• Peanuts
• Milk

What are the signs of a folic acid deficiency?

The signs of folic acid deficiency can be subtle. If you're only mildly deficient, you may not notice any symptoms at all, but you won't be getting the optimal amount of folic acid for your baby's early embryonic development.

If you do notice signs, they may include:

• Irritability
• Anemia
• Fatigue
• Sore tongue
• Diarrhea
• Weight loss
• Weakness
• Headaches
• Heart palpitations
• Shortness of breath

Reach out to your healthcare provider if you notice signs of a folic acid deficiency or if you have any questions about your folic acid requirements.

Learn more:

• What to do before you try to get pregnant
• Preconception checkup: Why you need one and what to expect
• 12 steps to a healthy pregnancy