ABSTRACT
The physiologic interaction of two or more mineral ions in the diet can have significant effects on health and welfare. While interactions involving dietary essential elements may be either detrimental or beneficial, the major concern is that an antagonistic element may induce a deficiency of its counterpart nutrient whose concentration in the diet is borderline. Assessment of such in-vivo interactions will be considered here under the concept of bioavailability. While interaction may occur at various sites, the major one that limits bioavailability occurs at the site of absorption in the intestinal mucosa. It should be noted that we know little about the mechanisms involved in the absorption of mineral elements. Besides the intestinal mucosa, interactions occur at ion channels in the plasma membranes of many cell types. An understanding of these interactions may provide a model for the interactions that occur at the absorption level. Present knowledge of interactions at ion channels is based on in-vitro experiments; consequently, such interactions may have little or no physiologic significance. Nevertheless, understanding the function of ion channels could be instructive with regard to the mechanisms involved in intestinal absorption. In- vitro mineral ion interactions are discussed under the topic, ion channels.
