Why pregnant women need to take folic acid

As soon as you get pregnant, keeping your baby healthy—before and after birth—becomes your top priority. Because the well-being of mom and baby is closely connected, one of the easiest ways to bring a healthy newborn home from the hospital is to take good care of yourself during pregnancy. 

There are lots of different ways to do this, but one of the most agreed-upon tips for a healthy pregnancy is to increase your intake of folic acid. Taking a sufficient amount of folic acid during pregnancy can prevent about 50% of neural tube defects, according to the American Academy of Pediatrics (AAP).

But how much folic acid should you take for pregnancy…and when do you need to start? Here’s a guide to one of the most vital nutrients needed during pregnancy for a healthy baby. 

What is folic acid?

Folic acid is found as part of Vitamin B and is used by every cell in the body for growth and development.  Part of the vitamin B9 family, folic acid helps your body make new cells, including skin, hair, and red blood cells (because of this, it may also help prevent anemia). It’s important to take folic acid for pregnancy, but you actually need it all the time, not just when you’re growing a baby! 

Many foods, like breakfast cereals, orange juice, and bread, are fortified with folic acid. But it also occurs naturally in some of the foods you eat every day, such as leafy green vegetables and beans.

Folic acid benefits

In the early stages of pregnancy, a fetus is undergoing major changes in growth and development. One of the most critical is the development of the neural tube, the structure that eventually becomes the baby’s brain, spinal cord, and skull. 

According to the Centers for Disease Control and Prevention (CDC), the neural tube forms sometime between the 17th and 30th day after conception; if it doesn’t close properly during this stage of development, it causes a neural tube defect (NTD) such as spina bifida or anencephaly. Both conditions are serious: While most babies born with spina bifida survive, they may have physical or mental disabilities due to an underdeveloped spinal cord or backbone—and anencephaly, an upper neural tube defect that prevents the brain from forming properly, is fatal. 

As scary as this all sounds, the good news is that healthcare providers  know folic acid supplementation is the best way to prevent these deficiencies during pregnancy. 

“The stuff that we know about neural tube defects is reliable,” says G. Thomas Ruiz, MD, an OB-GYN at MemorialCare Orange Coast Medical Center in California. “Women who are deficient in folic acid have an increased risk of giving birth to babies with a neural tube defect.”

In 2017, the United States Preventive Services Task Force called folic acid deficiency “one of the major preventable causes of neural tube defects,” and whole-heartedly recommends it to all women planning or capable of conceiving a pregnancy. Because it carries no real side effects, folic acid is an easy way to reduce your chances of NTDs with minimal risk to you or your baby’s health.

There may even be a few other benefits to taking folic acid during pregnancy, though they haven’t been well-studied. The CDC reports that it may reduce the risk for other birth defects, like cleft palate or lip and heart defects, and may help prevent certain kinds of cancer. 

Folic acid dosages during pregnancy

According to Dr. Ruiz, you should take a minimum of 400 micrograms (or 0.4 milligrams) of folic acid per day during pregnancy. Most prenatal vitamins, he adds, contain a higher dose of 800 micrograms (0.8 milligrams), which is a safe dosage (even though it’s twice as much as the minimum). 

There are a few exceptions to this dosage. If you are on an anti-epileptic drug, your provider may instruct you to take more folic acid every day. Dr. Ruiz says that these drugs carry a higher risk of neural tube defects. Per the Epilepsy Foundation, you may need to take up to 4 milligrams of folic acid daily if you’re also taking a medication to prevent seizures. It is important to talk with your healthcare provider before taking more than the standard dose of 400 micrograms daily.

The same recommendation applies to women with a family history of NTDs or who have previously given birth to a baby with one, says Mary Jane Minkin, MD, a clinical professor in the department of Obstetrics, Gynecology, and Reproductive Sciences at the Yale University School of Medicine.

“If you have had a baby with a neural tube defect, like spina bifida, you want to be taking 4,000 micrograms [or four milligrams] of folic acid before you conceive,” she recommends, but it is important to discuss this with your provider before starting higher than standard doses. If you have had a previous child with defects, it is important to talk with your provider before conceiving again or early in pregnancy about prenatal recommendations and screenings.

When should you consider limiting your intake of Folic Acid? 

On the other hand, if you have a B vitamin deficiency, particularly vitamin B12, you may need to carefully limit your daily folic acid intake. For the vast majority of the population, there is no danger associated with taking too much folic acid (you’ll just excrete any excess in your urine). But for people who are deficient in B12, taking large amounts of folic acid can permanently damage your nerve function, says Dr. Ruiz—though he clarifies that you would have to be taking upward of 4 milligrams per day, which is atypical unless you are at an increased risk for NTDs. If you have a history of B Vitamin deficiency, it is important to discuss with your provider your nutritional and supplemental needs before conceiving or early in pregnancy.

When should pregnant women start taking folic acid?

The easy answer? ASAP. 

“At minimum, as soon as a woman finds out she’s pregnant, she should start,” explains Dr. Ruiz, “though ideally you should start one to three months before trying to conceive.”

Thankfully, since many of the foods we eat are naturally rich in folate or vitamin-fortified, many women are already working with a baseline amount of folate in their bodies (assuming they eat a healthy diet). Dr. Minkin says that the average American gets about 140 micrograms of folic acid from breakfast cereals alone…but that you should still consider taking a daily multivitamin containing 400 micrograms of folic acid. All women at least between ages 13 and 50 (reproductive capable ages) should consider taking a multivitamin with 400 mcg of folic acid daily.

“Given that many pregnancies in this country aren’t planned, a good general recommendation is that if you aren’t using contraception 100% of the time, you probably should be taking some extra folic acid,” she explains. 

Because the crucial time for neural tube development is in early pregnancy—often before the majority of women even realize they’re pregnant—waiting until you get a positive sign on your pregnancy test might mean you’ve already missed the window for maximizing your folic acid benefits in the first trimester. It’s in the best interest for all sexually active women of childbearing age, it’s in the best interest of any possible pregnancies you take the minimum recommended amount of folic acid every day.

How to incorporate more folate into your diet

Now that you know how important it is to get enough folate during pregnancy, let’s talk about how you can include more of the good stuff into your diet. 

1. Take multivitamins. If you’re not currently pregnant but want to make sure you have a good baseline of folic acid, take a daily vitamin containing 400 micrograms. Most vitamins marketed to women will contain 100% of the daily value of folic acid, but always check the label to be sure.
2. Take a good prenatal vitamin if you’re pregnant. Your provider may recommend a specific brand or even give you a prescription, but you can also buy prenatal vitamins over-the-counter. (Dr. Minkin recommends the Vitafusion prenatal gummy.)
3. Drink orange juice. One serving can provide about 15% of the daily value of folate.  
4. Eat foods with labels that say they have been fortified with folate, like breakfast cereals, breads, flours, rice, pasta, and other grain products. 
5. Eat foods that boast high levels of folate naturally, like eggs, asparagus, spinach, bananas, avocados, broccoli, beans, oranges, and nuts. 

FYI, if you’re pregnant, you also need to be sure you’re taking a dietary supplement containing folic acid—working some form of folate into your diet naturally won’t be enough. The CDC website has some excellent folate resources and you can even take a quiz to test your folate knowledge!