Effects of Folic Acid-Fortified Milk Consumption on Serum Folate Levels in Japanese Female Students: a Randomized Controlled Trial Stratified by Methylenetetrahydrofolate Reductase C677T Genetic Polymorphism

Abstract

Objective: We studied effects of fermented milk fortified with 200 µg of folic acid (FF milk) on serum folate levels in Japanese female university students.Methods: Adopting FF milk as an intervention factor, a randomized controlled trial stratified by the methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphism was conducted in 143 university female students. Experimental group subjects were requested to consume FF milk for 4 weeks; control group subjects to consume usual meals. Dietary surveys were conducted using a food frequency questionnaire, and serum folate concentrations were analyzed adopting a chemiluminescence immunoassay. Utilizing oral mucous membrane swabs, MTHFR genotypes were determined with polymerase chain reaction followed by restriction fragment length polymorphism. Paired t-test, one-way analysis of variance, Pearson correlation coefficient, chi-square test, or Fisher's exact probability test was applied as appropriate.