The role of metals in human bio-chemistry illustrates clearly the dual nature of those trace elements which are both essential and toxic depends on its oxidation state and concentrations at which they are supplied. Each of these three essential elements (Cu, Fe & Mo) has three levels of biological activity, trace levels required for optimum growth with development, homeostatic levels (storage levels) and toxic levels at high concentrations. These essential metals are being investigated for their toxicity in excessive amount. The complete dose – responsive curve for essential metals shows a general complex activity spectrum comparable to that of Flow sheet. SURVIVALIST ► DEFICIENCY ► NORMAL HEALTH ►TOXICITY ► LETHALITY. Anyone struggles for survival very low levels of iron (causes Anemia), copper (causes Menkes) or molybdenum (causes molybdopterin). Lethal doses (LD100) due to over 60-mg / Kg iron oxide, Lethal dose (LD50) due to copper sulfate and Lethal dose (LD50) due molybdenum oxide. In between deficiency and toxic levels lies Normal Health Levels which maintain normal growth and development of humans.