Neural tube defects (NTDs) are serious birth defects of the spine (spina bifida) and brain (anencephaly), affecting approximately 3,000 pregnancies each year in the United States (1). Daily periconceptional consumption of 400 µg of folic acid, as recommended by the Public Health Service (PHS) since 1992, reduces the occurrence of NTDs by 50%--70% (2). The Food and Drug Administration ordered mandatory fortification with folic acid of U.S. cereal grain products, beginning in 1998. However, despite a 26% reduction in NTDs, not all women of childbearing age receive adequate levels of folic acid from their diets (1). Therefore, increasing the number of women who take dietary supplements containing 400 µg of folic acid daily remains an important component of NTD prevention (3). This report summarizes results from the 2005 March of Dimes Gallup survey, which determined a decrease in the proportion of childbearing-aged women who reported taking folic acid in dietary supplements daily,* from 40% in 2004 to 33% in 2005, returning to a level consistent with that reported during 1995--2003 (Figure). These results emphasize the need for innovative programs to increase folic acid consumption to further reduce NTDs.
The Gallup survey has been conducted since 1995 using a random-digit--dialed telephone interview of a proportionate stratified sample. Response rate for the 2005 survey was 32%, with 2,647 women aged 18--45 years responding; response rates for previous surveys ranged from 24% to 52%. Statistical estimates were weighted to reflect the total population of women aged 18--45 years in the contiguous United States who resided in households with telephones. The margin of error for estimates based on the total sample was +2%. To assess awareness of folic acid, respondents were asked, "Have you ever heard, read, or seen anything about folic acid?" To assess knowledge about folic acid, respondents were asked, "What have you heard, read, or seen about folic acid?" In addition, the survey asked questions regarding motivating factors and barriers to taking folic acid.
In the 2005 survey, 33% of women of childbearing age reported taking folic acid daily, compared with 40% in 2004. This decrease was consistent across most demographic characteristics, with nonwhite, young, less educated, and lower-income women the least likely to report taking folic acid daily (Table 1). The percentage of women reporting awareness of folic acid increased from 78% in 2004 to 84% in 2005, an all-time high for the survey. However, the percentage of women knowing that folic acid prevents birth defects remained unchanged at 25%, and the percentage of women knowing that folic acid should be taken before pregnancy decreased from 12% in 2004 to 7% in 2005, the lowest percentage since 1997 (Figure).
Twenty-six percent of women aged 18--45 years reported dieting during the preceding 6 months, relatively unchanged from 24% in 2004 (4). Of the women reporting dieting, 37% were taking folic acid daily and were nearly 30% more likely to be taking folic acid than nondieters (odds ratio [OR] = 1.27; 95% confidence interval [CI] = 1.13--1.41). Dieters were 50% more likely than nondieting women to believe that folic acid is important for women of childbearing age (OR = 1.50; CI = 1.34--1.68). Twenty-seven percent of dieting women reported being on low-carbohydrate diets, down substantially from 48% in 2004. Of the women on low-carbohydrate diets, 37% reported taking folic acid daily, down from 49% in 2004 (Table 2). In addition, 37% of women on other diets reported taking folic acid daily, down from 40% in 2004. Whereas in 2004 women on low-carbohydrate diets were 50% more likely to take folic acid daily than women on other diets, in 2005 folic acid consumption was similar among women in the two dieting groups (OR = 1.00; 95% CI = 0.81--1.24. Although in 2004, low-carbohydrate dieters were 30% more likely to believe that folic acid is important for women of childbearing age than women on other diets, in 2005, no difference was evident between women in these dieting groups (OR = 0.95; 95% CI = 0.76--1.18).
Women were asked questions to determine why they do or do not take vitamin or mineral supplements. Women who did not report taking supplements were asked, "Why do you not take any vitamin or mineral supplements on a daily basis?" The most common barriers women noted were forgetting to take supplements (28%), perceiving they do not need them (16%), and believing they get needed nutrients and vitamins from food (9%).
In 2005, to determine what might motivate women not taking vitamins or supplements to begin taking folic acid daily, respondents were asked, "For what specific need would you start taking a vitamin or mineral supplement?" The most common reported needs were being sick or in poor health (20%), a doctor's recommendation (20%), the need for energy (9%), being pregnant (8%), being deficient in any vitamins or minerals (7%), balancing the diet (6%), and keeping bones strong (6%). In addition, 11% cited no specific need that would motivate them to begin taking a vitamin or supplement. Among women who reported not consuming a vitamin or mineral supplement daily, 31% indicated they had received a doctor's recommendation. Older women were more likely to report receiving a doctor's recommendation (aged 35--45 years, 38%; 25--35 years, 38%; 18--24 years, 24%).
Reported by: LLM Lindsey, PhD, CDC Foundation, Atlanta, Georgia. JR Petrini, PhD, March of Dimes Birth Defects Foundation, White Plains, New York. H Carter, MPH, C Prue, PhD, J Mulinare, MD, Div of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, CDC.
Contact: Donna Vandergraff, Phone: 765-494-8228, E-mail: vandergraff@purdue.edu
Funded by Folic Acid Council grant from March of Dimes.
