IL2 and Zinc deficiency: In this model, as a result of zinc deficiency, we observed decreased serum testosterone level, oligospermia, decreased NK cell (natural kill cell) lytic activity, decreased IL-2 activity of T helper cells, decreased serum thymulin activity (thymulin is a thymic hormone essential for the development and maturation of T cells), hyperammonemia, hypogeusia, decreased dark adaptation, and decreased lean body mass (27–29).