Total zinc absorption from a diet containing either conventional rice or higher-zinc rice does not differ among bangladeshi preschool children

Abstract

Information is needed on zinc absorption from grain cultivars having higher zinc content. Total absorbed zinc (TAZ) from mixed diets containing high-zinc rice (HZnR), conventional rice (CR), or CR plus zinc fortificant (CR+Zn) was measured. Forty-two nonmalnourished preschool-aged children were enrolled in 1 of 2 groups. Using a crossover design, children in group A (n = 22) received for 1 d each a mixed diet containing 150 g CR or HZnR. Children in group B (n = 20) received HZnR on 1 d and CR+Zn on the other day. Fractional zinc absorption (FZA) was measured during each dietary period by using a dual-isotope tracer ratio technique; TAZ was calculated as the product of zinc intake [total dietary zinc (TDZ)] and FZA. TDZ was 3.83, 4.83, and 6.03 mg/d when the children were fed the CR, HZnR, and CR+Zn-containing diets, respectively. Mean FZA from the CR diet was greater than from the HZnR diet (25.1 vs. 20.1%, P < 0.001), and the mean FZA from the CR+Zn diet (18.8%) was less than from both the CR diet (P < 0.001) and the HZnR diet (P = 0.014). The mean TAZ was 0.96 ± 0.16, 0.97 ± 0.18, and 1.13 ± 0.20 mg/d from the CR, HZnR and CR +Zn diets, respectively. TAZ was not different for the CR and HZnR diets (P = 0.99) but was significantly greater from the CR+Zn diet compared with the other 2 diets (P < 0.001). Rice cultivars with higher zinc and/or lower phytate content are needed to increase TAZ by young children consuming this amount of rice. © 2013 American Society for Nutrition.