Daily Zinc Supplementation, But Not Intermittent or Therapeutic Zinc Supplementation, Increases Plasma Zinc Concentration and Does Not Affect Iron and Vitamin A Status in Young Children

Abstract

Objectives: To assess the effect of three zinc supplementation strategies, provided with diarrhea and malaria treatment, on zinc, iron and vitamin A status. Methods: During a community-based, cluster-randomized, zinc supplementation trial, we collected venous blood at baseline and after 48 weeks in a random subsample of 451 rural Burkinabe children 6-18 mo old assigned to 4 groups: 7 mg zinc/d, ORS+placebo for diarrhea (DPZ); 10 mg zinc/d for 10d/16wks followed by daily placebo, ORS+placebo for diarrhea (IPZ); daily placebo, ORS+20mg zinc/d for 10d for diarrhea (TDZ); no intervention (NI). Supplemented children were treated for fever and malaria. Blood hemoglobin concentration (Hb) was measured by HemoCue®. Plasma zinc concentration (pZn), measured by ICP-AES, and plasma ferritin (pF), transferrin receptor (TfR) and retinol-binding protein (RBP) concentrations, measured by ELISA, were adjusted for inflammation. Results: High baseline rates of anemia (88.5% had Hb<11 g/dL), iron deficiency (50.5% had pF<12 ug/L; 89.9% had TfR>8.3 mg/L ), vitamin A deficiency (48.9% had RBP<0.83 umol/L) and zinc deficiency (43.5% had pZn<65 ug/dL) were not different by group. Over 48 weeks, pZn increased significantly more in DPZ (+5.8±1.9%) than in TDZ (-0.7±1.8%) and NI (-1.7±1.3%) but not than in IPZ (+2.3±1.7%). 48-week changes in Hb, pF, TfR and RBP did not differ by group. Conclusions: Daily preventive, but not intermittent preventive or therapeutic zinc supplementation, increased pZn over 48 weeks. Zinc supplementation with malaria and diarrhea treatment did not affect iron and vitamin A status.