Impact of Dietary Zinc Supplementation on PEM

Summary of published research¹

Zinc deficiency is one of several trace element deficiencies that may play a pivotal role in the development of Protein Energy Malnutrition (PEM). A number of indicators can be used to identify geographical areas where zinc deficiency may be a problem:

• Staple foods are high in phytate and/or low in zinc and/or high in calcium
• The consumption of zinc dense foods (particularly meat) is low
• There is a high prevalence of stunting in young children (low height-for-age for children < 5 years of age)
• There is a heavy burden of infectious disease
• There is a high prevalence of iron deficiency
  Many of these indicators can be found in Lesotho. Consequently, the aim of a recent study was to examine the impact of zinc supplementation in the management of children with PEM, aged 6 months to 5 years, in Lesotho.

In a randomised controlled double blind clinical trial, supplementation with 10 mg of elemental zinc as zinc sulphate was evaluated in the management of PEM. Atotal of 300 Basotho children aged 6-60 months (150 children in each group) admitted to the Queen Elizabeth 11 hospital, Maseru, Lesotho were included in the study. Supplementation and follow up were conducted for three months post-discharge from the hospital.

Mortality during hospitalisation was significantly lower in the zinc supplemented group (4.7%) compared with 16.7% in the control group. The prevalence of morbidity was significantly higher in the control group at 1, 2 and 3 month's follow up. In the zinc supplemented group, 58 percent of the children were above the 80th percentile of expected weight-for-age three months after discharge, compared with 27.6% in the control group. Dietary zinc supplementation resulted in a significant reduction in diarrhoeal disease, respiratory morbidity, and episodes of clinical anaemia, skin infections and fever, as well as vomiting, in children with PEM. These findings suggest that interventions to improve zinc intake in their management may be of benefit to Basotho children in Lesotho with PEM.

The authors of the study conclude that although zinc deficiency may not be a feature of malnutrition on presentation, failure to provide sufficient zinc may well delay convalescence and even limit the rate of growth in these children.

¹Makonnen B, Venter A and Joubert G (2003), A randomised controlled study of the impact of dietary zinc supplementation in the management of children with proteinenergy malnutrition in Lesotho. I: Mortality and morbidity. Journal of Tropical Paediatrics, vol 49, no 6, pp 340-351