Folate intakes and blood concentrations of adults in NHANES 2003‐2004

Abstract

High folate intake (>400μg) among older persons may result in adverse health outcomes and likely produce elevated serum folate concentrations, as shown in earlier National Health and Nutrition Examination Surveys (NHANES). We examined the impact of folate fortification and supplement use on intake and circulating folate concentrations of persons >45 years in NHANES 2003‐2004 stratified by gender and four race‐ethnicity groups: non‐Hispanic white (NHW), non‐Hispanic black (NHB), Mexican American (MA) and Other (O).NHB and NHW men consumed less refined, non‐whole grains than O males (p=0.008) and less legumes than MA and O (p=0.019). MA women consumed more grains (p=0.007) than NHW and NHB races, and more legumes than all races (p=0.006). NHB men had the lowest mean red blood cell (RBC) folate concentrations (p<0.001) and the lowest mean serum folate concentrations (p=0.003) of all races, while NHW women had the highest serum concentration (p=0.001). Female folate‐containing supplement users consumed more food folate than non‐supplement users (p=0.012). All supplement users are at risk of high serum folate concentrations and older (>65 years), NHW women who use supplements are more likely to have elevated RBC folate concentrations. These findings highlight the need to better understand the effects of chronic exposure to elevated folate intakes.