The supplement is so essential that the U.S. government requires all enriched grain foods to be fortified with 140 micrograms of folic acid per 100 grams of grain.
Survey results find daily use of folic acid has not shown a substantial increase between 1995 and 2005, despite nationwide educational efforts by the March of Dimes and other agencies.
In the 2005 survey, 33 percent of women of childbearing age reported taking folic acid daily, compared with 40 percent in 2004.
The number of women who say they are aware of folic acid reached an all-time high in the 2005 survey at 84 percent, up from 52 percent in 1995. The most common reason women gave for not taking the daily supplement is forgetfulness.
According to Dr. Jennifer Howse, president of the March of Dimes, "Folic acid must be part of women's daily diet. That's the best way we know to spare thousands of babies the risk of death or disability caused by neural tube defects."
The March of Dimes says all women capable of becoming pregnant should take a multivitamin containing at least 400 micrograms of folic acid every day, before pregnancy, to help prevent neural tube defects, such as spina bifida and anencephaly.
Studies show, if all women consumed the recommended amount of folic acid before and during early pregnancy, up to 70 percent of all neural tube defects could be prevented.
The study is published in Friday's issue of the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report
