Absorbed zinc and exchangeable zinc pool size are greater in pakistani infants receiving traditional complementary foods with zinc- fortified micronutrient powder

Adequacy of zinc intake from breast milk alone becomes marginal in relation to infant requirements by around 6 mo of age.Simple and cost-effective strategies are needed at the population level to ensure adequate intakes of zinc in infants andtoddlers in populations at risk of zinc deficiency. We determined the amount of absorbed zinc (AZ) from a micronutrientpowder (MNP) without and with 10 mg of zinc (MNP+Zn) added to local complementary foods used in Pakistan and theimpact on the exchangeable zinc pool (EZP) size. As a nested study within a large, prospective, cluster randomized trial,6-mo-old infants were randomly assigned to receive MNP or MNP+Zn. Stable isotope methodology was applied after ~3and 9 mo of use to measure AZ from MNP-fortified test meals of rice-lentils (khitchri) and EZP. Nineteen infants per groupcompleted the first metabolic studies and 14 and 17 infants in the MNP and MNP+Zn groups, respectively, completed thefollow-up studies. AZs were (mean SD) 0.1 ± 0.1 and 1.2 ± 0.5 mg at the first point for the MNP and MNP+Zn groups,respectively (P < 0.001); results were nearly identical at the follow-up measurement. EZP did not differ between groups atthe first measurement but was less in the MNP group (3.7 ± 0.6 mg/kg) than in the MNP+Zn group (4.5 6 1.0 mg/kg) atthe second measurement (P = 0.01). These data confirm that the MNP+Zn in khitchri were well absorbed and after 1 y ofhome fortification, zinc status assessed by EZP was significantly better for the MNP+Zn group. Additional field studiesmay be necessary to ascertain the adequacy of this dose for infants at high risk of deficiency.