Factors Affecting Dietary Intake of Copper and Zinc via Rice Consumption by Residents of Major Rice-Producing Regions in China

Background: Copper (Cu) and zinc (Zn) are essential nutrients that must be maintained at adequate levels in the human body in order to make physiological functions normal and sustainable. Rice is a leading staple cereal crop which can be the main source of Cu and Zn in the diet. Results: Here, we aimed to investigate Cu and Zn concentrations in rice with corresponding soil influencing factors and to assess the dietary intake of Cu and Zn from rice consumption by residents of major rice producing regions. A total of 712 rice grain and 90 paired soil–rice samples were collected from September to November 2015 covering eleven provinces across China. Average Cu and Zn concentrations were 27.2 and 69.1 mg kg −1 , respectively, in soils, and 1.98 and 12.3 mg kg −1 in rice. The concentrations and bioconcentration factors (BCFs) of Cu and Zn followed the sequence: roots > shoots > grains. Soil pH, cation exchange capacity (CEC), and soil organic carbon (SOC) play important roles in rice Cu and Zn uptake with negative effects. The average Cu and Zn intakes from rice consumption were 0.597 and 3.68 mg day −1 , respectively. Conclusions: The status of Cu and Zn daily intake from rice consumption were fully adequate but there remained some sampling sites where Zn intake for males and Cu intakes were deficient at 1.40%, indicating that local residents need to maintain their dietary nutrient requirements.