Previous research has shown that zinc supplements can reduce the incidence of diarrhoea and pneumonia in children in countries with few resources.
However, the HIV virus requires zinc for its structure and function, and zinc activates lymphocytes that are target cells for HIV-1 replication. These factors have raised concerns about the safety of giving HIV-infected children supplements of zinc.
Only observational studies and small trials, and none on children, have investigated the potential risks.
In the new trial, Dr William Moss from the Johns Hopkins School of Public Health and colleagues recruited 96 children, aged between six months and five-years-old, from a South African hospital.
The children were randomly assigned to receive 10mg of zinc sulphate or a placebo daily (provided by French firm Nutriset) for six months.
Zinc supplementation did not result in an increase in blood HIV viral load but it did reduce diarrhoea and also improved weight gain.
Children given zinc gained an average 7 per cent of their bodyweight after six months compared to just 2 per cent for the placebo group. This difference was no longer significant three months after supplementation stopped.
There were no differences for visits due to other reasons such as pneumonia, upper respiratory tract infection or ear infection.
"These results are consistent with those of trials of zinc supplementation in children without HIV-1 infection," write the authors in the 26 November issue of the journal (vol 366, pp1862-67).
They say that zinc supplementation should be used as an adjunct therapy for children with HIV-1 infection as a simple and cost-effective way of cutting mortality in this group.
"Few interventions are available to reduce morbidity in children with HIV-1 infection in resource-poor countries. Although UNAIDS, WHO, and their partners are committed to providing antiretroviral therapy to 3 million people by the end of 2005, antiretroviral therapy and prophylaxis for opportunistic infections are not accessible for many children."
"Consequently, more than half these children die before the age of three years, most commonly of respiratory tract infections and diarrhoeal diseases…"
"Programmes to enhance zinc intake in deficient populations with a high prevalence of HIV-1 infection can be implemented without concern for adverse effects on virus replication," they added.
A new report published by the World Health Organisation this week shows that the number of people living with HIV is at its highest ever - 40.3 million. More than 3 million people died of AIDS-related illnesses in 2005, with more than 500,000 of these children.