Folic Acid and Birth Defect Prevention

Folic acid is the synthetic form of folate, a B vitamin found naturally in dark-green leafy vegetables, citrus fruits, beans, and whole grains. It plays an important part in the development of the fetus' spinal cord and brain. You should eat foods and supplements containing folic acid one month prior to conception and during your first trimester of pregnancy.

Folic acid deficiency can cause severe birth defects of the brain and spinal cord known as neural tube defects. In some cases, there may be no noticeable signs of folic acid deficiency, and it is diagnosed in pregnant women only after a child is born with a neural tube defect. Usually, though, your health-care provider can detect the deficiency with ultrasound during your prenatal checkups. If women were to take the recommended amount of folic acid before they conceive and through the first trimester of pregnancy, 50% to 70% of these cases could be prevented. Yet recent research by March of Dimes shows that 7% of women are unaware of the importance of folic acid.

Where can I find it? (Sources)

There are many ways to get the folic acid your body needs. It is available in folic acid tablets, multivitamins, breads, rice, pastas, and fortified cereals. While many of these fortified foods contain about 10% of the daily RDA (Recommended Daily Allowance), a few cereals contain a full day's supply of folic acid. It is also possible to get enough folic acid by eating large amounts of liver, dark-green leafy vegetables, citrus fruits, whole grains, and dried beans and peas.

How much do I need? (Recommendations)

The Institute of Medicine's Food and Nutrition Board recommends the following:

Adults should have 400 micrograms of folate daily. Women capable of becoming pregnant should receive this amount with folic acid supplements, not just fortified foods, to ensure the proper daily intake.

Adults should not take in more than 1 milligram (1,000 micrograms) of folate daily. This is because folic acid may be toxic under certain circumstances. People with vitamin B absorption problems and those taking certain epilepsy drugs are especially at risk. Before beginning to take folic acid supplements, consult your health-care provider.

Women who have had a previous pregnancy with a neural tube defect should take a higher dosage of folic acid for their next pregnancy of at least 4 milligrams a day.

Frequently asked questions (FAQ)

Q: If I take enough folic acid will my baby be safe from neural tube defects?

A: It will certainly help, but taking folic acid supplements does not always guarantee that your baby won't be born with a defect. While nearly half of the 2,500 annual cases of neural tube defects are caused by folic acid deficiency, other risk factors for these defects include:

Family history of neural tube defects.

Prior pregnancy with neural tube defects.

Certain antiseizure medications.

Being extremely overweight.

Sitting in a hot tub or jacuzzi during early pregnancy.

Experiencing a fever during early pregnancy.

Having diabetes.

Q: What should I look for in a supplement containing folic acid?

A:  Look for labels that say, "Adequate folate intake may reduce the risk of neural tube birth defects." In order to make these FDA-approved claims supplements must contain: 10% or more of the RDA for folic acid; have no more than 100% of the RDA for vitamins A and D; and carry a caution about toxic levels of intake.

Q: If folic acid is so important, why is it so hard to get women to take it?

A:  Some women do not like to take vitamins, while others have stomach trouble when they take prenatal vitamins. Also, it is often difficult for most people to change their dietary habits. The research establishing the importance of folic acid is very new. Until recently, few health-care providers informed their patients about the need of taking it prior to conception.