Risk Assessment for Essential Trace Elements in Humans

Abstract

Almost a century ago, the great French scientist Gabriel Bertrand established what is known as Bertrand’s Law, on the basis of his many observations on the effects of trace elements on growth and metabolism of plants (1), providing the scientific basis for the total dose-response curve of all living matter to all essential nutrients. In its most basic terms the law states that for each biological system there is a range of exposure, compatible with and essential for optimal function, and that below and above that range function deteriorates, resulting in disease and, ultimately, death. Thus, essential trace elements, like all essential nutrients, present two risks: One of deficiency and another of toxicity. Because both must be considered before any nutritional intervention can be safely implemented, the definition of the range of safe and adequate intakes for all essential elements for all systems of interest is the supreme challenge in our field.