Study on Dietary Folate Intake and Serum Folate Concentration in the Middle-Aged and Elderly Population in Japan

Abstract

There are little scientific data to estimate the dietary reference intake of vitamins in Japan. New additional information is needed on the requirements and dietary intake for folate. Therefore, this study was designated to evaluate the dietary folate intake and the serum folate concentration in middle-aged and elderly population (n=120, 61.7±8.5y) in Japan. The dietary folate intake was 442±119μg/day and 432±118μg/day for the annual average in men and women, respectively. There were no large differences between sexes. On the other hand, the folate concentration in the serum was 5.8±2.2ng/ml for the annual average in men, which significantly differed from 7.8±2.8ng/ml in women (p<0.05). The serum folate concentration was highest in summer and lowest in winter. A seasonal variation in both men and women was clearly observed. From these findings, it is suggested that the recommended dietary allowance for folate should be estimated, primarily taking into account a sex difference.