Babies born to mothers who consume too little folate early in their pregnancies are at high risk of neural tube abnormalities, which can be devastating birth defects of the brain or spine. To reduce this risk, the Food and Drug Administration mandated that as of 1998, U.S. manufacturers had to fortify grain-based foods with folic acid, the stable form of this B vitamin. A new analysis now attributes a roughly 25 percent drop in neural tube defects to the change.
Researchers with the Centers for Disease Control and Prevention in Atlanta pored over data from 23 birth defect registries that cover about half of U.S. births. Extrapolating their findings to the rest of the country, the researchers say that prior to the folic acid–fortification rule, an average of 4,130 neural tube defects occurred each year. After folic-acid enrichment of foods began, this number dropped to 3,020, the investigators report in the May 7 Morbidity and Mortality Weekly Report (MMWR).
"Because about half of all pregnancies in the United States are unplanned, all women who can get pregnant should consume 400 milligrams of folic acid each day," contends Patricia Mersereau, a contractor with CDC and lead author of the new report.
Although the measured drop in birth defects is steep, it is "less than what was estimated from research trials" and well below the federal health objective of reducing the occurrence of spina bifida and other neural tube defects by 50 percent of the 1996 level by 2010, according to an editorial note in the same issue of MMWR.
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