Background:
Neural tube defects (NTDs) occur in 1 of every 1,480 pregnancies in California. These birth defects can be reduced by 50% by daily intake of the B vitamin folic acid starting three months before conception and through the first trimester of pregnancy. NTD risk factors include Hispanic ethnicity, young age, obesity and poor diet quality. Studies show that even among high risk populations, daily folic acid can reduce the incidence of NTDs.

Objectives:
Estimate daily folic acid intake among California women at elevated risk for NTDs.

Methods:
We analyzed daily folic acid supplement intake for years 2004 and 2005 using data from the California Women's Health Survey, a state-wide, random-digit dial telephone survey of women. Results were weighted to reflect the population of women age 18-44 in California using the 2000 census.

Results:
Overall, 39.8% of California women age 18-44 reported taking a folic acid-containing supplement daily. Among all race/ethnic subgroups, pregnant women were significantly more likely to report daily folic acid intake (>80%) than women trying to become pregnant and those who were not. Younger women, women experiencing food insecurity, and Hispanic women were least likely to report daily folic acid intake (29%, 29% and 28%, respectively). Results for Hispanic women are especially troubling since NTDs are 50% more common among California's Hispanic women than among Caucasian women.

Conclusion and implications for practice:
Populations at elevated risk for NTDs --- Hispanic women, younger women, and women with poor diet quality --- are also the least likely to take folic acid supplements. However, prenatal vitamin promotion appears successful at encouraging folic acid intake among pregnant women of all race/ethnic subgroups. Folic acid should be as aggressively promoted to all women of reproductive age as prenatal vitamins are to pregnant women. The California Departments of Public Health and Health Care Services should investigate culturally appropriate folic acid interventions focused on these high risk groups, including social marketing, counseling, and expanding distribution of no- or low-cost folic acid supplements.