Why you need folic acid
If you’re pregnant or might become pregnant, you need folic acid (vitamin B9) for a number of compelling reasons.
Folic acid helps prevent neural tube defects (NTDs)—serious birth defects of the spinal cord (such as spina bifida) and the brain (such as anencephaly). Neural tube defects occur at a very early stage of development, before many women even know they’re pregnant. They affect about 3,000 pregnancies a year in the United States.
The Centers for Disease Control and Prevention (CDC) reports that women who take the recommended daily dose of folic acid starting at least one month before conception and during the first trimester of pregnancy reduce their baby’s risk of neural tube defects by 50 to 70 percent.
Some research suggests that folic acid may help lower your baby’s risk of other defects as well, such as cleft lip, cleft palate, and certain types of heart defects.
Your body needs folic acid to make normal red blood cells and prevent a type of anemia. Folic acid is also essential for the production, repair, and functioning of DNA, our genetic map and a basic building block of cells. So getting enough folic acid is particularly important for the rapid cell growth of the placenta and your developing baby.
Some research suggests that taking a multivitamin with folic acid may reduce your risk of preeclampsia, a complex disorder that can affect your health and your baby’s.
How much folic acid you need
To reduce your baby’s risk of developing a neural tube defect, experts recommend that you take 400 micrograms (mcg) of folic acid per day, beginning at least a month before you start trying to get pregnant.
In fact, because half of the pregnancies in the United States are unplanned, the CDC, the U.S. Public Health Service, the March of Dimes, the American College of Obstetricians and Gynecologists (ACOG), and other experts strongly recommend that all women of childbearing age get 400 mcg of folic acid every day.
Some groups, such as the U.S. National Institutes of Health, suggest boosting your intake to at least 600 mcg daily once you’re pregnant.
The neural tube—from which your baby’s spine and brain develop – begins to form about three weeks after conception, so it’s critical to get a sufficient daily dose of folic acid before conception and during the first trimester of pregnancy.
Check the label of your multivitamin supplement to be sure you’re getting enough. If you’re not, you can switch brands or take folic acid separately. (Never double up on your multivitamins.)
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 particularly important if you are a vegan. Vegans are at risk of being deficient in vitamin B12 and taking too much folic acid would make it hard to diagnose that deficiency.
When you might need extra folic acid
Women who are obese appear to be more likely to have a baby with a neural tube defect, although the reason for this is still unclear. If you’re significantly overweight, see your healthcare provider before you try to conceive. She may advise you to take more than 400 mcg of folic acid a day.
If you’ve previously been pregnant with a baby with a neural tube defect, be sure your current providers are aware of this and schedule a visit before you try to get pregnant. With no intervention, women in this situation have a 2 to 5 percent chance of having another pregnancy complicated by an NTD.
The good news is that this risk can be reduced significantly by taking a very large dose of folic acid. Talk to your doctor about how much folic acid you should take if you’re in this situation.
Women who are diabetic or are taking certain antiseizure medications are also more likely to have a baby with an NTD. If either of these situations applies to you, 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.