According to the charity Save the Children, more than 10 million children worldwide under the age of five die every year. In the overwhelming majority the cause of death is a preventable or treatable disease like diarrhea (2 million deaths a year) or pneumonia (1.9 million deaths).
In half of the overall deaths, malnutrition is a contributing factor.
The researchers in the joint study conducted by the International Center for Diarrhea Disease Research in Bangladesh and John Hopkins University in Baltimore, USA, were aware that daily supplementation with zinc has been reported to prevent acute lower respiratory tract infection and diarrhoea, and reduce child mortality.
Other recent studies have shed light on the mineral's role in benefiting the cardiorespiratory function, boosting children's cognitive abilities and warding off the common cold.
Led by Dr W Abdullah Brooks, the researchers set out to determine whether a weekly dose could prevent clinical pneumonia and diarrhea in under twos. Their findings are published online today in The Lancet
The study involved 1621 children in Kamalapur, Bangladesh, aged between 60 days and 12 months, 809 of whom were randomly selected to receive 70mg of zinc each week for 12 months. The other 812 children received a placebo.
Field research assistance assessed the children on a weekly basis. They noted that there were 199 incidences of pneumonia in the zinc group compared to 286 in the placebo group, but none of the pneumonia patients in the zinc group died. Ten children in the placebo group died of pneumonia.
Zinc was also seen to have a "small but significant" effect on incidence of diarrhea, with 1881 cases and two deaths in the zinc group compared to 2407 and 14 deaths in the placebo group.
Overall mortality was reduced by 85 percent for those infants taking zinc.
Lead author Dr W Abdullah Brooks said that zinc might be progressively protective against more invasive and severe disease, and that the overall reduction in mortality seemed to be primarily due to pneumonia.
Despite the apparent success of the study, the researchers were aware that compliance with weekly intake might be problematic in a developing country, outside a research program.
Last year Unicef warned that the UN may not achieve its goals of eradicating extreme poverty and reducing child mortality by two-thirds by 2015 due to widespread nutrient deficiencies in the developing world. It called on the food industry to develop and distribute low-cost fortified foods and supplements, and for governments to create a supportive environment to allow such products to reach the affected populations.
The Vitamin Angel Alliance, said to be the "humanitarian arm of the natural products industry" last year shipped 23.4 million supplements with a wholesale value of $2.2 million to health care facilities and organizations in over 45 different countries.