Neural Tube Defects Are Preventable: Buy Corn Masa Flour and Tortilla Products That Contain Folic Acid Interview with: Vijaya Kancherla, PhD, Research Assistant Professor, Department of Epidemiology, Epidemiologist, Center for Spina Bifida Prevention, Rollins School of Public Health, Emory University.  The scientific evidence since 1991 has shown that folic acid prevents from 35%-95% of neural tube birth defects that are caused due to low folic acid (also known as vitamin B9) in the mother’s diet prior to conception and during early pregnancy. Neural tube defects form in the embryo at 4th week of gestation when most women are unaware they are pregnant.  Read the full story.