In their recent report, Williams et al1 examined data from 21 population-based birth defect surveillance systems for trends in prevalence of spina bifida and anencephaly for specific racial/ethnic groups from 1995 to 2002. Data were stratified into pre-, optional, and mandatory fortification intervals, coincident with the authorization of folate fortification of enriched cereal-grain products by the Food and Drug Administration (FDA) in 1996. Williams et al1 found prevalence values per 10000 births for spina bifida for Hispanic, non-Hispanic white, and non-Hispanic black women of 4.18, 3.37, and 2.90, respectively, for the mandatory fortification interval versus corresponding values for the same groups of 6.49, 5.13, and 3.57, respectively, for the prefortification interval. These results suggested that folate fortification was associated with significant decreases in the prevalence of spina bifida among non-Hispanic white and Hispanic births (34% and 36% decreases, respectively). The 19% decline in the prevalence of spina bifida among non-Hispanic black births was borderline statistically significant.1 This failure to find a statistically significant decline among non-Hispanic black births may have been attributable to smaller samples examined (total cases were 515 for non-Hispanic black births, 2672 for non-Hispanic white births, and 1281 for Hispanic births). In their editorial on the article by Williams et al,1 Brent and Oakley2 argued that folic acid fortification levels in the United States are too low. They have inappropriately generalized the data of Williams et al1 into a broad criticism of the current folic acid fortification program and a call for increased fortification. This warrants our response. Consideration of whether increases in fortification are warranted depends a number of complex issues. For example, are the residual neural tube defects (NTDs) in all racial/ethnic groups folate sensitive? If so, then would increasing the levels of folic acid in enriched cereal-grain products … Address correspondence to Jeanne I. Rader, PhD, Division of Research & Applied Technology, Office of Nutritional Products, Labeling and Dietary Supplements, Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5100 Paint Branch Pkwy, College Park, MD 20740. E-mail: Jeanne.Rader{at}cfsan.fda.gov