Zinc (Zn) absorption from SprinklesTM is not affected by iron (Fe) in Kenyan infants in malaria endemic area

Abstract

Interference with Zn absorption is one proposed explanation for adverse effect of Fe supplements in Fe‐replete subjects in malaria endemic areas. We determined the effect of Fe on Zn absorption and size of exchangeable Zn pool (EZP) after 3 mo of micronutrient (MN) home fortification with SprinklesTM in maize‐based diets in rural Kenyan infants.Methods6 mo old infants were randomized to 1 of 3 groups: MN+Zn (5 mg) + Fe (12.5 mg); MN+ Zn (5 mg); or placebo. At 9 mo, fractional absorption of Zn (FAZ) was measured by a dual isotope tracer ratio method, using extrinsic labels (67Zn) added to SprinklesTM meal, and to all other meals excluding breast milk (70Zn); 68Zn was administered IV. EZP was calculated from urine 68Zn enrichment. Zn intake (ZI) was measured by duplicate diet analyses. Absorbed Zn (AZ) = FAZ × ZI.ResultsAZ from non‐SprinklesTM meals = 0.2 mg/day in all groups. AZ from SprinklesTM meals and EZP by group were: Group (n) ZI (mg) FAZ AZ (mg) EZP (mg/kg) MN+Zn +Fe (10) 5.1 (0.02)* 0.12 (0.12) 0.60 (0.6) 3.7 (1.2) MN+Zn (8) 5.2 (0.26) 0.14 (0.21) 0.70 (1.1) 4.0 (1.2) Placebo (9) 0.1 (0.03) 0.25 (0.11) 0.02 (0.01) 3.0 (1.9) Mean (SD) ANOVA indicated no significant differences for any variable. ConclusionsAlthough increased Fe intake was not associated with impaired Zn absorption or EZP size, the low AZ relative to estimated physiologic requirement suggests higher doses of Zn in SprinklesTM may be desirable. Supported by NIH K24DK083772 and IAEA.