Gazette
masthead
   About The Gazette Search Back Issues Contact Us    
The newspaper of The Johns Hopkins University March 26, 2007 | Vol. 36 No. 27
 
Zinc Supplements Found to Reduce Mortality in Older Children

By Tim Parsons
School of Public Health

A clinical trial conducted by researchers at the Johns Hopkins Bloomberg School of Public Health concluded that daily zinc supplements reduced the risk of death among children ages 12 months to 48 months by 18 percent. However, the researchers did not find any significant reduction in mortality among children 1 month to 11 months. The study is published in the March 17 edition of The Lancet.

Zinc is one of the most plentiful trace elements in the body, second only to iron. It mediates many physiological functions and is believed to be essential for maintaining a healthy immune system. The trial examined whether zinc supplementation would benefit children living in areas where malaria is prevalent. Pneumonia, diarrhea and malaria account for 45 percent of the 10 million child deaths worldwide each year.

"This large trial demonstrates that the benefits of zinc supplementation include mortality reduction in addition to the reduction in cases of pneumonia, diarrhea and malaria that we found in previous trials," said Robert Black, the study's senior author and professor and chair of the Bloomberg School's Department of International Health.

The double-blind trial involved 42,546 children living in Pemba, Zanzibar. Half the children were randomly selected by household to receive daily zinc supplements, while the other half were given a placebo. Overall, the study found a 7 percent reduction in the risk of mortality with zinc supplementation, a number that was statistically insignificant, and a statistically significant 18 percent reduction in mortality in children ages 12 months to 48 months. According to the Johns Hopkins researchers, the interaction between zinc effects and age is consistent with the results of other studies.

They said it is possible that infants acquire sufficient amounts of zinc in utero and through breast-feeding to sustain them during the first year of life. The failure to find an effect in infants could also be a result of the lower doses of zinc given to infants compared to the higher doses given to older children. In the trial, infants given zinc received a 5mg dose, while children 12 months and older received a 10mg dose.

Sunil Sazawal, the study's lead author and associate professor in the Department of International Health, said, "While further work is needed to evaluate higher dose effects, recommendations for use of zinc as a preventive strategy need to consider the collective evidence of the effect on growth, morbidity and mortality, which would suggest benefit in children ages 6 months and up."

Additional authors of the study are Mahdi Ramsan, Hababu M. Chwaya, Arup Dutta, Usha Dhingra, Rebecca J. Stoltzfus, Mashavi K. Othman and Fatma M. Kabole.

The research was supported by grants from the World Health Organization Department of Child and Adolescent Health and Development, United Nations Foundation, United States Agency for International Development and Bill & Melinda Gates Foundation.

GO TO MARCH 26, 2007 TABLE OF CONTENTS.
GO TO THE GAZETTE FRONT PAGE.


The Gazette | The Johns Hopkins University | Suite 540 | 901 S. Bond St. | Baltimore, MD 21231 | 443-287-9900 | gazette@jhu.edu