ARS | Publication request: Changing the zinc:iron ratio in a cereal-based nutritional supplement has no effect on percent absorption of iron and zinc in Sri Lankan children

Submitted to: British Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 8, 2009
Publication Date: April 2, 2010
Citation: Hettiarachchi, M., Liyanage, C., Hilmers, D., Griffin, I., Abrams, S.A. 2010. Changing the zinc:iron ratio in a cereal-based nutritional supplement has no effect on percent absorption of iron and zinc in Sri Lankan children. British Journal of Nutrition. 103(7):1015-1022.

Interpretive Summary: We were interested in studying the amount of iron and zinc that would be absorbed from a food used to feed small children in Sri Lanka. We used stable isotopes and measured the absorption of these isotopes in a group of about 50 children age 4 to 7 years. We found that the zinc absorption was not dependent of iron amount in the supplemental food, but that iron absorption increased with more iron content. This investigation showed the benefit of maintaining a high amount of iron in supplements and the importance of trying to increase the amount of zinc they contain.

Technical Abstract: The Thriposha program is a community-level nutrition intervention in Sri Lanka that provides a combination of energy, protein, and micronutrients as a 'ready-to-eat' cereal-based food. We measured the bioavailability of Fe and Zn from Thriposha formula at two different molar ratios of Zn: Fe in order to determine the effect on Fe and Zn absorption. Children 4–7 years (n=53) were given a meal prepared with 50 g Thriposha, containing 1.5mg Zn as zinc sulphate and either 9mg (high Fe concentration (HiFe)) or 4.5mg (low Fe concentration (LoFe)) Fe as ferrous fumarate. Zn and Fe percent absorption were measured using stable isotopes by tracer: tracee ratio and by incorporation of erythrocytes, respectively. Percent Fe absorption from the two meals was similar (6.6% (4.8) v. 4.8% (2.6); P=0.15), but total Fe absorption was significantly higher from the HiFe meal (0.59 (0.43) mg) than the LoFe meal (0.20 (0.12) mg; P=0.01). There was no significant difference between the two groups in Zn absorption (10.7% (0.9) v. 8.8% (1.4), P=0.13, respectively). Decreasing the amount of Fe in Thriposha did not cause a significant change in the percent absorption of Fe and Zn, but significantly lowered the total amount of absorbed Fe. These results demonstrate the utility of maintaining a higher Fe content in this supplement. Further studies to increase Zn content are warranted while maintaining a HiFe.