Zinc Deficiency in Human Health

Zinc exposure is receiving increasing attention as a public health problem because of the U-shaped dose-response curve in which adverse health effects are associated with the presence of either too little or too much zinc in the vulnerable tissues or organs. The growing scientific interest and research have led to a paradigm shift in terms of which arm of the U-curve should be of most concern to public health. Attention was focused for years on zinc toxicity because of the general belief that zinc deficiency could not occur in humans because zinc was assumed to be ubiquitous and plentiful in our diets. About 40 years ago, zinc was recognized as an essential micronutrient for human health by Dr. Ananda Prasad, a nutrition chemist at Wayne State University in Detroit, Michigan. Since then, various laboratory and clinical tests combined with many zinc supplementation trials have led to the documentation of widespread incidence of zinc deficiency in human populations. Today, zinc deficiency is recognized as a nutritional problem worldwide, pandemic in both developed and developing countries. The risk factors for the silent epidemic of zinc deficiency are primarily environmental in origin.