Estimation of Folic Acid Intake and Blood Concentration in Korean Adults Using a Newly Established Folic Acid Database

Objectives: Previously, a new database for folic acid was established for 3894 foods which had appeared in the Korea National Health and Nutritional Examination Survey (KNHANES). In this study, we re-analyzed KNHANES VII (2016–2018) data using the new DB for folic acid to determine the folic acid intake of Koreans and analyzed related factors. Methods: Among the 24,269 participants in KNHANES VII, 15,054 individuals (6,278 men, 8,776 women) were selected as the participants, who had all the findings, such as sociodemographic variables, lifestyle characteristics, and food intake. In a study on the relationship between blood concentration and folic acid intake, the participants were 5,260 individuals (2,272 men, 2,988 women). Folic acid intake according to sociodemographic and lifestyle characteristics was calculated after adjusting for energy intake and age. The relationship between folic acid intake and serum concentration was tested by linear regression analysis of the complex samples, after adjusting for the confounding factors (IRB approval number: 2018-01-03-P-A). Results: The daily folic acid intake was lowest in the 19–29 years age group (279.21 ± 4.36 μg DFE/day) and highest in the 50–64 years age group (401.93 ± 4.20 μg DFE/day). The participants with high levels of education and income, non-smokers, and high aerobic physical activity had higher folic acid intake (p< 0.001). Among the food groups contributing to folic acid intake, the first and second rankings were vegetables (first rank was cabbage kimchi, contribution of 37.76%) and cereals (contribution of 16.91%), respectively. Mean blood folic acid concentration of all participants was 7.30±0.07 ng/mL. In adjusting for variables related to folic acid intake-related variables, such as energy intake, age, income, smoking, aerobic physical activity, and dietary supplement intake, the β coefficients of folic acid intake on blood concentration were 0.219 and 0.360, respectively, and as folic acid intake increased, blood folic acid concentration significantly increased (p< 0.001). Conclusions: The folic acid nutritional status of Korean adults in their 20s and 30s and aged > 75 years of age should be improved. The newly established folic acid DB is expected to help evaluate the folic acid nutritional status of Koreans. Funding Sources: This work was supported by research fund of Chungnam National University.