E-mail: Jacobien Veenemans
Currently at Amphia
Effects of supplementation with zinc and other micronutrients on the health, development and well being of African children
Micronutrient supplementation is a potentially cost-effective way to reduce the burden of infectious diseases among poor populations in rural Africa. Zinc is essential for the functioning of the immune system, and preventive zinc supplementation may reduce the incidence of malaria among children in areas of intense transmission by enhancing the development of a protective immune response. Our study aimed to determine the effects of supplementation with zinc and other multi-micronutrients on the incidence of malaria in children. To achieve this, we provided a daily oral supplement containing zinc (with or without multiple micronutrients), or a placebo, to 612 children under 5 years of age in a rural area in Tanzania.
The field work
A research dispensary was established centrally in the study area, with an approximate population of 4500 people (1500 children under 5), and without previous access to nearby health-facilities. The residents virtually all comprise poor farmer families engaged in subsistence farming who are living in self-constructed clay houses. Electricity and running water are not available. The dietary intake of absorbable zinc in this population is probably low because of the low dietary intake of animal products, and local staple crops (predominantly maize, beans and cassava) have high concentrations of phytate and polyphenols that impair zinc absorption. Children were followed for a period of 7-13 months, and daily supplementation was carried out by a network of 40 community volunteers, who were supervised by project staff at the research dispensary. Malaria morbidity was assessed using a health-facility-based morbidity surveillance system; mothers were asked to bring their children to the dispensary (that was open 24 h per day) immediately when they noticed fever or any other sign of illness.
Upon closure of the field work of the trial, the dispensary was taken over by the Tanzanian Ministry of Health, and the Kilimanjaro Christian Medical Centre. It will continue to provide medical care to the residents in the area.
Data are now being analysed. The effect of zinc and/or multinutrients on malaria will be calculated as the percentage reduction in the total number of malaria episodes relative to placebo. In addition, we will assess effects on the incidence of respiratory infections and diarrhoea, and how intestinal parasites such as Giardia intestinalis influence the effect of supplementation. We expect to present the first findings in December 2009.