Abstract
OBJECTIVE: This study is to examine the relationship between dietary selenium intake and 24-h urinary selenium excretion in Japanese population samples participating in the INTERMAP Study. METHODS: Using highly standardized methods, we assessed individual dietary selenium intake from four 24-h dietary recalls and measured urinary selenium excretion in two timed 24-h urine collections in 1145 Japanese participants (574 men and 571 women) ages 40-59 years in four areas of Japan. RESULTS: The medians of dietary selenium intake were 177.5 microg/day in men and 139.8 microg/day in women; the medians of 24-h urinary selenium excretion were 127.9 microg/day in men and 109.4 microg/day in women, that is, urinary excretion was estimated to be 73% of dietary intake in men and 77% in women. Dietary selenium intake was significantly correlated with 24-h urinary selenium excretion (r=0.24 in men, r=0.18 in women; P<0.001). With dietary selenium intake and urinary selenium excretion expressed per kg of body weight, values were similar for men and women (dietary intake, 2.7 microg/kg body weight in men and 2.5 microg/kg body weight in women; urinary excretion, 2.0 microg/kg body weight in men and 2.0 microg/kg body weight in women). CONCLUSION: Dietary intake and 24-h urinary excretion of selenium are related in the Japanese adult population.