Intake and excretion of cadmium of Japanese adult

It is the aim of this study if the recent Cd intake and excretion is consistent with the regression equation proposed by Ikeda et al. (Environ. Health Prev. Med. 20 (2015) 455-459) which utilized intake/excretion data of 3 decades ago METHOD: Matched duplicate diet and spot urine samples were collected in 2017-2019 from 150 Japanese adults (85 females and 65 males, mean age being 44.9) for the estimation of daily Cd intake and urinary excretion. Cd concentration in diet and urine was measured by ICP mass spectrometry.

Geometric mean (geometric standard deviation) of Cd intake was 12.1 (1.67) μg/person/day or 0.206 (1.66) μg/kg body wt./day. Urinary Cd concentration was 0.54 (2.6) μg/g creatinine or 0.67 μg/L (2.3) (gravimetric correction). These were lower than those reported previously for Japanese populations. Urinary concentration was significantly higher in females than in males for both creatinine and gravimetric corrections. Dietary intake was higher in males than in females but this difference diminished after body weight correction. There was no significant correlation between Cd intake and urinary concentration on individual basis, which was expected because urinary Cd concentration reflects Cd body burden but not recent intake level. Meanwhile, the geometric mean intake and urine concentration was consistent with the regression equation proposed by Ikeda et al., which was based on intake and excretion surveys for 30 non-exposed Japanese female populations.

This result supported that the regression equation of Ikeda et al. could be used for conversion of urinary Cd excretion level of a population to intake level.