Iron and zinc co-supplementation seems to be most helpful for children in developing countries

Research Activities, September 2010, No. 361

Zinc and iron deficiencies often coexist in malnourished child populations of developing nations. Zinc is important in reducing childhood morbidity and mortality from diarrhea and pneumonia, while iron prevents anemia and may also improve psychomotor activity. However, various studies have called into question the safety of universal iron supplementation and the advisability of co-supplementation with iron and zinc. A new study shows that separate and combined administration of iron and zinc are equally effective for reducing diarrhea, hospitalizations, and improving iron outcomes (e.g., increased hemoglobin).

Stephanie Chang, M.D., of the Agency for Healthcare Research and Quality, and international colleagues examined the interaction of zinc and iron supplementation on diarrhea, hospitalizations, and other outcomes for 1,000 6- to 18-month-old children in a rural area of Bangladesh. Each child received one of five regimens (placebo, zinc alone, combined iron and zinc, iron alone, or iron and zinc separately). Overall supplement adherence during the followup period was 81.9 percent.

Iron alone increased diarrhea, but zinc added to iron, either separately or together, reduced diarrhea and hospitalizations. In fact, any combination of zinc (alone, combined with iron, or separately with iron) significantly decreased the incidence of diarrhea with dehydration compared with iron alone. Stunted children benefitted more from separate (vs. combined) iron and zinc supplementation. There were a total of 80 hospitalizations, with bronchiolitis being the most common reason. Other reasons for hospital admission were diarrhea, viral infection, and pneumonia. Zinc and iron, together or separately, reduced hospitalizations the most. Zinc, given alone, reduced infection-related hospitalizations whereas any combination of zinc reduced bronchiolitis hospitalizations.

The researchers concluded that iron and zinc co-supplementation seems to help with diarrhea, blood levels of iron, and hospitalization for this population. They note that their findings are applicable to non-malaria-endemic populations with similar plant-based, nutrient-poor diets.

See "Supplementing iron and zinc: Double blind, randomized evaluation of separate or combined delivery," by Dr. Stephanie Chang, M.D., Sadia El Arifeen, M.D., Sanwarul Bari, M.D., and others in the European Journal of Clinical Nutrition 64, pp. 153-160. Reprints (AHRQ Publication No. 10-R053) are available from the AHRQ Publications Clearinghouse.

Page last reviewed September 2010
Internet Citation: Iron and zinc co-supplementation seems to be most helpful for children in developing countries: Research Activities, September 2010, No. 361. September 2010. Agency for Healthcare Research and Quality, Rockville, MD.