Other Neural Tube Defects (NTDs) FAQs

Basic information for topics, such as “What is it?” is available in the About Neural Tube Defects (NTDs) section. Answers to other Frequently Asked Questions (FAQs) specific to NTDs are in this section.

What is the best way to prevent NTDs?

Folic acid (also known as vitamin B9) has been shown to reduce the risk that a fetus will have an NTD.1 A majority of NTDs can be prevented by taking 400 mcg of folic acid daily both before and during pregnancy.2

Since 1992, the U.S. Public Health Service has recommended that all women of childbearing age consume 400 mcg of folic acid daily to reduce the risk of a pregnancy affected by an NTD. The best ways for women to get enough folic acid are by taking vitamin supplements and by eating foods with added folic acid (including most cereals, breads, pasta, and other grain-based foods). Orange juice and leafy green vegetables (such as kale and spinach) contain a form of the supplement called folate, but the body absorbs folic acid better than it absorbs folate.3

All pregnant women and women who may become pregnant should take 400 mcg of folic acid daily, preferably in the form of a supplement. The advisory about folic acid includes all women—not just those who are now pregnant—because NTDs occur so early during pregnancy, often before a woman even knows she is pregnant. The advisory also includes women who are not even planning on pregnancy, because half of all pregnancies are not planned.

In 1996, the U.S. Food and Drug Administration mandated that folic acid be added to breads, cereals, and other grain products.1 One study found that the number of infants born with spina bifida or anencephaly dropped by about 28% after folic acid was added to these products. It also estimated that each year, about 1,326 fewer infants are born with an NTD as a result of adding folic acid to foods in the United States.4

Many health care providers recommend that women who have already had a pregnancy affected by an NTD or who have spina bifida themselves take a higher prescription dose of folic acid (4 mg) daily at least 3 months before becoming pregnant and during pregnancy.5 (This dosage should be prescribed and monitored by the health care provider.)


  1. Centers for Disease Control and Prevention (CDC). (2016). Birth defects: Data & statistics. Retrieved February 23, 2017, from http://www.cdc.gov/ncbddd/birthdefects/data.html
  2. CDC. (2016). Folic acid: Data and statistics. Retrieved February 23, 2017, from http://www.cdc.gov/ncbddd/folicacid/data.html
  3. Institute of Medicine, Food and Nutrition Board. (1998). Dietary reference intakes: Thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline. Washington, DC: National Academies Press.
  4. Williams, J., Mai, C. T., Mulinare, J., Isenburg, J., Flood, T. J., Ethen, M., et al. (2016). Updated estimates of neural tube defects prevented by mandatory folic acid fortification — United States, 1995–2011. Morbidity and Mortality Weekly Report, 64(01), 1–5. Retrieved March 19, 2018, from https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6401a2.htm
  5. CDC. (2016). Folic acid: Recommendations. Retrieved February 16, 2018, from https://www.cdc.gov/ncbddd/folicacid/recommendations.html
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