Zinc Deficiency in Low and Middle Income Countries: Prevalence and Approaches for Mitigation

Abstract

This review addresses the prevalence of zinc deficiency in Low and Middle Income Countries (LMICs) and assesses the available strategies for its alleviation. The paucity of national level data on the zinc deficiency in LMICs is partially due to the lack of a reliable biomarker. Zinc deficiency appears to be a public health problem in almost all the LMICs irrespective of the recommended indicators (plasma zinc concentration, dietary zinc adequacy and stunting prevalence) used. Based on plasma/serum zinc concentration (PZC), the most appropriate indicator at present, the prevalence of zinc deficiency in LMICs are of concern. Among the 25 countries for which national PZC data were available, 23 had a zinc deficiency prevalence of >20% for at least one physiological group. Zinc supplementation is largely restricted as an adjunct therapy for diarrhoea management in children, but the best platform and the most effective way of preventive zinc supplementation delivery needs to be determined. Impact assessment for current zinc fortification programmes in LMICs and the effectiveness of zinc supplementation as part of a multi-micronutrient powder is to be ascertained. Dietary diversification, though promising for LMICs, is in nascent stages of development at present. Inclusion of meat and animal products can be an important way to improve zinc status. Programmatic experience with the promotion of home processing techniques to increase absorbable zinc in the diet is lacking. Conventional biofortification techniques are gaining recognition in LMICs, however transgenic biofortification as a strategy remains controversial.