Zinc is a metallic element which exists in micro-quantaties in the human body. However, deficiencies in zinc have been linked to a host of different diseases. What characterizes a deficiency in zinc? How widespread is the global prevalence for zinc deficiency and what are some possible causes? What are some sources of zinc found available in the diet and how well are they utilized biologically? What role does zinc play in metabolism and what is the potential health impact for deficiencies in zinc?