Na2EDTA Enhances the Absorption of Iron and Zinc from Fortified Rice Flour in Sri Lankan Children

Abstract

Rice flour was proposed as a vehicle for iron and zinc fortification in Sri Lanka. Although widely consumed, rice flour has not been evaluated as a fortified food, and the absorption of minerals including iron and zinc from this flour is unknown. Determination of the bioavailability of these nutrients is a critical step before commencing a fortification program. We randomly divided 53 Sri Lankan schoolchildren ages 6–10 y into 4 groups that consumed a local dish prepared with 25 g of fortified rice flour labeled with one of the following: 1) ⁵⁸FeSO₄2) ⁵⁸FeSO₄ + Na₂EDTA 3) ⁵⁸FeSO₄ + ⁶⁷ZnO or, 4) ⁵⁸FeSO₄ + Na₂EDTA + ⁶⁷ZnO. The levels of iron and zinc were 60 mg/kg; the rice flour also contained folate at 2 mg/kg in each group. Na₂EDTA was added at a Fe:Na₂EDTA, 1:1 molar ratio. A total of 48 children completed the trial. Absorption of ⁵⁸Fe from a meal was significantly greater (P < 0.01) in the groups administered FeSO₄ + Na₂EDTA (4.7 ± 3.6%) than in those administered FeSO₄ without Na₂EDTA (2.2 ± 1.3%). Fractional absorption of zinc was 13.5 ± 6.0% in the FeSO₄ + Na₂EDTA group and 8.8 ± 2.0% in the FeSO₄ group (P = 0.037). Although zinc absorption was low, our results demonstrated a benefit in using Na₂EDTA to improve both iron and zinc absorption. We conclude that the fortification of rice flour is feasible, although additional strategies such as dephytinization or an increase in the level of iron and zinc fortification should be considered to obtain a higher proportion of the daily requirement of total absorbed iron and zinc.