The immune system is governed by a large number of influences. An important support of the nutritional dependent changes of the reaction to immunity is represented by the prostaglandin and leukotriene system. The basis are essential and non-essential highly unsaturated fatty acids which are transformed by the body's own enzyme system in oxidative steps. As coenzyme and cosubstrate, for instance Vitamin B6 and zinc, are needed--tests show the influence of pyridoxine and folic acid on the immune system. The significance of minerals, especially zinc, iron and selenium, for the immune metabolism will be demonstrated. Selenium deficiency leads, evidently, to a reduction in the ability to stimulate the lymphocytes and decreases the phagocytosis index of the macrophages--some risk groups, responsible for the appearance of the state of malnutrition, will be pointed out and pharmaco-therapeutic prevention measures will be described.