Zinc and Health: Workshop Summary

Session I

Session I, Zinc Nutrition highlighted the very diverse roles of zinc and biology, and highlighted the existence of a wide range of zinc deficiencies that impinge on an organisms innate drive to maintain homeostasis.  Because of our inability to identify and quantitate zinc deficient states due to lack of good diagnostic tools or biomarkers, our understanding of zinc nutrition has been thwarted.  What is needed is a simple and reliable measure of marginal and moderate zinc deficiency. It was discussed how zinc modeling techniques, an approach that enables rate differences to be determined in conditions that have been modified by diet, environment, genetics, or disease, could move the field in a forward direction. The development of techniques for the accurate determination of isotopes in biological materials bound to different compounds will allow the kinetics of zinc to be measured. Histoanalytic methods that selectively quantify the weakly-bound zinc found in many types of secretory granules may also prove a powerful tool for assessing zinc status. The physiological adjustments necessary to maintain zinc homeostasis with changes in needs were also summarized. These adjustments are sensitive to changes in dietary intake as well also as endogenous needs. Whole body zinc homeostasis is maintained primarily through adjustments in GI zinc absorption and endogenous excretion. The signal to the GI tract to alter zinc uptake and excretion has not been identified. If identified this signal could be a good biochemical indicator of zinc status. The technique of differential display of mRNA has proved to be a valuable technique to identify genes involved with zinc homeostasis and function.