Background: Zinc is one of the most important trace elements in the biological systems. It involves in the activities of more than 300 enzymes (e.g. lactic dehydrogenase, carbonic anhydrase, alkaline phosphatase). Biological activities of Zinc include cell development, production of sex and growth hormones and skin structure.

Materials and Methods: during last decades, we have done serial research projects with zinc and its protective effect on other toxic elements, which have been published in international journals.

Results: we have found that this element may bind to transferrin during blood circulation and cause anemia as key indicator in man who intoxicated with this element, and the production of Zinc-protoporphyrin could be observed due to Zinc toxicity. The protective effect of zinc on cadmium-induced changes in thyroid, parathyroid and bone functions are shown in lab animal treated by Zinc.

Conclusions: frequent determination of Zinc in serum may be helpful for our body health.