Folate intake estimated with an updated database and its association to blood folate and homocysteine in Korean college students

Objective: To measure folate content in cooked foods commonly consumed in Korea for evaluating its relation to folate nutriture of college students. Design: Folate content in 32 raw and cooked foods was measured by microbiological assay after trienzyme extraction. These values and the previously published values of 110 raw foods commonly consumed in Korea were used to update the currently available food tables to estimate dietary folate intake of 106 students based on a 3-day 24-h recall. The association of folate intake with blood folate and homocysteine concentrations was evaluated. Setting: Cheongju, Korea. Subjects: Healthy college students aged 18 to 27 y old ( 44 males and 62 females). Results: The average folate loss in 32 foods caused by cooking was 29%. The mean daily dietary folate intakes estimated with an updated database were 406 and 305 mug in males and females, respectively. About 10% of both male and female students showed low serum folate (<6.8 nmol/l). Folate intake was positively correlated with serum and erythrocyte folate concentrations in female students (r = 0.27 and 0.29, respectively, P < 0.05), and negatively correlated with serum homocysteine in male students (r = -0.41, P < 0.05). Conclusions: Mean dietary folate intake was higher than those of previous studies since the database was updated using values obtained with trienzyme extraction. Folate intake for the general population should be re-evaluated using reliable food folate values obtained with trienzyme extraction.