Effects of separate delivery of zinc or zinc and vitamin A on hemoglobin response, growth, and diarrhea in young Peruvian children receiving iron therapy for anemia

Am J Clin Nutr. 2004 Nov;80(5):1276-82. doi: 10.1093/ajcn/80.5.1276.


Introduction: Anemia is the most prevalent nutritional deficiency in the world. Attempts to improve iron indexes are affected by deficiency of and interaction between other micronutrients.

Objective: Our goal was to assess whether zinc added to iron treatment alone or with vitamin A improves iron indexes and affects diarrheal episodes.

Design: This was a randomized, placebo-controlled, double-blind trial conducted in Peru. Anemic children aged 6-35 mo were assigned to 3 treatment groups: ferrous sulfate (FS; n = 104), ferrous sulfate and zinc sulfate (FSZn; n = 109), and ferrous sulfate, zinc sulfate, and vitamin A (FSZnA; n = 110). Vitamin A or its placebo was supplied only once; iron and zinc were provided under supervision >/=1 h apart 6 d/wk for 18 wk.

Results: The prevalence of anemia was 42.97%. The increase in hemoglobin in the FS group (19.5 g/L) was significantly less than that in the other 2 groups (24.0 and 23.8 g/L in the FSZn and FSZnA groups, respectively). The increase in serum ferritin in the FS group (24.5 mug/L) was significantly less than that in the other 2 groups (33.0 and 30.8 mug/L in the FSZn and FSZnA groups, respectively). The median duration of diarrhea and the mean number of stools per day was significantly higher in the FS group than in other 2 groups (P < 0.005).

Conclusion: Adding zinc to iron treatment increases hemoglobin response, improves iron indexes, and has positive effects on diarrhea. No additional effect of vitamin A was found.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anemia, Iron-Deficiency / drug therapy*
  • Anemia, Iron-Deficiency / epidemiology
  • Child, Preschool
  • Diarrhea / drug therapy*
  • Diarrhea / epidemiology
  • Double-Blind Method
  • Drug Therapy, Combination
  • Female
  • Ferrous Compounds / therapeutic use*
  • Hemoglobins / drug effects*
  • Humans
  • Infant
  • Male
  • Peru / epidemiology
  • Prevalence
  • Vitamin A / administration & dosage
  • Vitamin A / therapeutic use*
  • Zinc Sulfate / administration & dosage
  • Zinc Sulfate / therapeutic use*


  • Ferrous Compounds
  • Hemoglobins
  • Vitamin A
  • ferrous sulfate
  • Zinc Sulfate