When it comes to preventing certain birth defects, folic acid - a B vitamin - plays a crucial role. Getting adequate amounts of folic acid reduces a woman's risk of having a baby with a neural tube defect (such as spina bifida or anencephaly) by 50% to 70%. In 1996, the U.S. Food and Drug Administration (FDA) mandated that manufacturers of cereals, breads, and other grain products enrich their products with folic acid by January 1998. Now that folic acid fortification has been in place for years, researchers from the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, investigated just how effective this strategy has been in preventing neural tube defects (NTDs), which involve the incomplete development of the brain and spinal cord.
Using data from 21 states, researchers compared spina bifida and anencephaly cases that occurred between 1995 and 2002. They divided and compared the cases in three groups:
- births between January 1995 and December 1996 (before foods were fortified with folic acid)
- births between January 1997 through September 1998 (when some foods were enriched with folic acid, but it wasn't required)
- births between October 1998 and December 2002 (when it was required that grain products be fortified with folic acid)
Overall, researchers identified 4,468 cases of spina bifida and 2,265 cases of anencephaly. The number of spina bifida and anencephaly cases differed by race - these NTDs were most common in Hispanic infants, followed by white infants. They were least likely to occur in black infants. The most significant declines in spina bifida and anencephaly rates between the prefortification and the mandatory fortification periods occurred in Hispanic and white infants.
The authors of an editorial accompanying this journal article suggested that the FDA hasn't done enough to improve folic acid consumption, though. They pointed out that if most women of reproductive age had adequate folic acid intake, spina bifida and anencephaly could be almost completely eradicated. Public health organizations recommend that all women of reproductive age - not just pregnant women, but any woman who could possibly become pregnant - consume at least 400 micrograms of folic acid daily to prevent NTDs. But the FDA required food manufacturers to fortify foods at a level that would provide only 100 micrograms of folic acid to the average woman of reproductive age, despite arguments for higher fortification levels by organizations such as the American Academy of Pediatrics, the March of Dimes, and the CDC. To further reduce NTDs in the United States, the authors of the editorial say, the FDA should at least double the requirement for folic acid concentration in enriched grains. They also stress that the FDA should ensure that manufacturers of corn-flour based products (such as Maseca, which has manufacturing plants in the United States) enrich their products with folic acid, since Hispanic families are disproportionately affected by NTDs.
What This Means to You: Although it is still not certain why Hispanic and white women in the U.S. are more likely to have babies with spina bifida or anencephaly, this study suggests that folic acid fortification has had a positive impact in reducing the number of these birth defects. Despite these positive findings, many women still do not get the recommended amounts of folic acid in their daily diets. All pregnant women and women of child-bearing age - even if they don't plan to become pregnant - should get at least 400 micrograms of folic acid every day. Adequate folic acid intake is very important 1 month before conception and at least 3 months afterward to reduce the risk of having a fetus with a neural tube defect. To make sure you're getting enough folic acid every day, talk to your doctor about taking a multivitamin or folic acid vitamin supplement.
Source for main article: Laura J. Williams, MPH; Sonja A. Rasmussen, MD; Alina Flores, MPH; Russell S. Kirby, PhD; Larry D. Edmonds, MSPH; Pediatrics, September 2005
Source for accompanying editorial: Robert L. Brent, MD, PhD; Godfrey P. Oakley, Jr., MD, MSPM; Pediatrics, September 2005
Reviewed by: Steven Dowshen, MD
Date reviewed: October 2005
