WASHINGTON — Fortifying corn masa flour with folic acid may increase folic acid intake by nearly 20% in Mexican-American women, according to a study conducted by the Centers for Disease Control and Prevention (C.D.C.) and published in the January issue of the American Journal of Clinical Nutrition.

While all women are susceptible to having a child born with a neural tube defect (N.T.D.)., studies have shown Hispanic women in the United States have the highest rates of babies born with N.T.D.s., in some cases a 30% to 40% higher risk than the average U.S. population. Adding folic acid has been shown to prevent up to 70% of N.T.D.s if taken before pregnancy.

The most recent C.D.C. study used data from the National Health and Nutritional Examination Survey 2001-2004 (NHANES) to estimate the folic acid content in foods containing corn masa flour if fortified at a level of 140 µg folic acid per 100 grams of corn masa flour.

According to the findings, had corn masa flour fortification occurred, Mexican-American women ages 15 to 44 may have increased their total daily folic acid intake by 19.9% and non-Hispanic white women by 4.2%.

"The increased consumption of folic acid through corn masa flour fortification could provide an added level of protection for Mexcian-American women," said Alina Flores, health education specialist at the C.D.C.’s National Center on Birth Defects and Developmental Disabilities. "But we still need more research to understand why Hispanics have higher prevalence rates of N.T.D.s."