Population-level changes in folate intake by age, gender, and race/ethnicity after folic acid fortification

Objectives. We sought to quantify the impact of the 1998 US Food and Drug Administration (FDA) folic acid fortification policy by estimating folate intake at the population level. Methods. We analyzed total folate intake levels (from food and supplements) according to gender, age, and race/ethnicity, using data from 2 National Health and Nutrition Examination Surveys. We measured pre- and postfortification folate intake distributions, adjusted for measurement error, and examined proportions of the population who reached certain thresholds of daily total folate intake. Results. Mean daily food and total folate intake increased by approximately 100 μg/day after fortification. The proportion of women aged 15-44 years who consume more than 400 μg/day of folate has increased since fortification, but has not yet reached the FDA's 50% target and varies by race/ethnicity from 23% to 33%. Among persons aged 65 years and older who may be at risk for masking a vitamin B12 deficiency, the percentage who consume more than 1000 μg/day (the "tolerable upper intake level") has at least doubled among Whites and Black men, but has remained less than 5% for all groups. Conclusions. Since fortification, folic acid intake among the US population has increased, and there are substantial variations by age, gender, and race/ethnicity.