<i>In Vivo–In Vitro</i> Correlations for the Assessment of Cadmium Bioavailability in Vegetables

Abstract

The correlation of <i>in vitro</i> and <i>in vivo</i> assays for determining bioavailable Cd amounts in vegetables is limited. Herein, the correlations between Cd relative bioavailability (Cd-RBA) in rat models and Cd bioaccessibility in four <i>in vitro</i> assays were examined in vegetables. Results showed that the combined liver plus kidney data provided the appropriate endpoint and was used as a biomarker to estimate Cd-RBA. The Cd-RBA was negatively correlated with the mole ratio of Ca/Cd and Fe/Cd in vegetables. Strong <i>in vivo-in vitro</i> correlations were found from physiologically based extraction test (PBET) and <i>in vitro</i> gastrointestinal (IVG) (<i>R</i>² = 0.66-0.69). We concluded that PBET and IVG were optimal models for Cd-RBA determination in vegetables. The nutritional elements in the vegetables could affect Cd absorption. Furthermore, the Cd bioavailability in vegetables should be considered because risk estimates solely based on the total Cd concentration in vegetables would overestimate Cd intake.