Recent studies of antagonistic interactions in the aetiology of trace element deficiency and excess

Abstract

In recent years, evidence from both field and laboratory studies has shown that a number of trace element deficiencies arise or can be induced as a result of biological interactions between these nutrients. Similarly, some of the toxic effects resulting from the ingestion of excessive amounts of both essential and non-essential elements may be ascribed to interactions with biological processes directly or indirectly involving other trace elements. Some appreciation of the range and complexity of the trace element interactions that may occur under practical situations can be obtained from Fig. I. In this paper a positive interaction is defined as one in which the presence of one element is essential for the normal metabolic action of a second element and a negative interaction as one in which the presence of an excess of one (or more) element antagonizes the normal actions of a second. It is clear that a complete discussion of all these complex interactions is beyond the scope of this review and thus a selected few will be considered in order to highlight some of the important features characteristic of these interactions.