Folate Intakes and Folate Biomarker Profiles of Pregnant Japanese Women in the First Trimester

Objective: To assess the status of dietary folate intake, serum and red blood cell (RBC) folate, and related nutritional biomarkers in healthy Japanese women in early pregnancy.

Design: A cross-sectional, observational study.

Subjects: Pregnant women in the first trimester, at 7-15 weeks gestation (n=70), who were not consuming any folate supplements or folate fortified foods.

Methods: Three-day dietary records were obtained from each subject to assess dietary folate intake. Blood samples were collected for measurement of biomarkers. Biomarkers and nutrient intake were analyzed in two groups defined by their serum folate concentrations: the low folate group (serum folate < 9 ng/ml) and the high folate group (serum folate > or = 9 ng/ml).

Result: Mean serum and RBC folate concentrations in all subjects were 10.3 and 519 ng/ml, respectively. These levels were remarkably higher than the reported values from many other countries despite our subjects receiving no folic acids supplements. However, mean folate intake by our subjects from natural foods was 289 microg/day, which is thought to be low according to the Japanese dietary recommendation specified for pregnant women. The intake of spinach and fruits was significantly greater in the high folate group than in the low folate group.

Conclusion: Folate intake was thought to be adequate to maintain a desirable level of serum folate concentration in Japanese pregnant women in the first trimester, although the intake of folate from natural food was not high enough to meet the recommended daily intake.