Estimation of daily selenium intake by 3- to 5-year-old Japanese childrenbased on selenium excretion in 24-h urine samples

Abstract

To evaluate the daily Se intake of 3- to 5-year-old Japanese children, we used seventy-two urine samples collected fromfifty-three children (twenty-sevenmale and twenty-six female) from two cities in Miyagi prefecture, Japan. For measuring low Se concentrations with high precision, accuracy and rapidity inthe 24-h urine samples, we developed an instrumental neutron activation analysis (INAA) method, that is without any chemical separation, using the short-lived77mSe (t1/2=17·4 s) nuclide. The estimated Se intake of thefifty-three children was 51·5(SD30·2) μg/d (geometric mean: 42·7 μg/d). Ten subjects(three male and seven female), successfully provided 24-h urine samples over two or three consecutive days; their Se intake was 37·4(SD5·9) μg/d. Basedon the logarithmically transformed data of these ten subjects, the ratio of intra-/inter-individual variances of usual Se intake was 16·7 (28·0/1·7) and geo-metric mean was 27·7 μg/d. The 5th to 95th percentile of usual Se intake of these ten subjects was 17·5to40·4 μg/d, which ranged between the recom-mended dietary allowance and tolerable upper intake level of Se by the Dietary Reference Intakes for Japanese (2015).