Iron and Zinc: Two Principal Trace Element Nutrients in the Context of Food Security Transitions

The underlying premise of this series is that food insecurity and food scarcity will continue to emerge due to underlying environmental, agricultural and demographic imperatives. For iron and zinc, which represent the two most abundant trace elements in the human body, decreased food availability and declining caloric requirements have predictive consequences. Overt deficiency of both produces public health consequences. Iron deficiency affects stamina and cognitive and immune function, evolving in its extreme form to iron deficiency anemia. Zinc deficiency is associated with poor growth and decreased disease resistance. In a food-security context, these two nutrients are most abundant and most biologically available in animal-source foods. From plant sources, the absorption efficiency is low due to intrinsic inhibitors such as phytic acid. Actions to improve nutritional status and mitigate the effects of food insecurity need to be conceptualized, evaluated for efficacy, and integrated into public policy. Dietary diversification toward greater contribution of animal-source food is problematic in the face of environmental issues and agriculture trends. Periodic, weekly or daily iron supplementation is used situationally, but presents challenges in terms of acceptability and safety. Zinc supplementation is restricted to specific indications in selected sub-populations. Food fortification and the newer approach of biofortification offer the greatest theoretical promise for both nutrients.