Zinc is a mineral that is severely deficient in the majority of people around the world, and over 50% are marginally deficient in zinc.  Our daily intake should approach 15 mg, and since there is no storage of zinc in the body, this quantity should be replaced daily.  It has been estimated that the average American consumes somewhere between 8 – 11 mg of zinc daily.  Why is zinc so important?  Because it is associated with several hundred enzyme systems in the body.  It is the most important mineral in terms of proper immune function.   Individuals who continuously have more than a few colds and the flu, or any kind of infection, are usually deficient in zinc.   Another area of interest for zinc supplementation is in afflictions of the prostate.  The very small amount of zinc that is concentrated in the human body is found in the prostate.  In older men, as the prostate swells restricting the flow of urine, zinc can reduce the inflammation and swelling of the prostate.  The usual dosage is 30 mg morning and night.  Other clues of zinc deficiency can be found in skin, hair, teeth and nails.  The graying of hair is a zinc deficiency, as well as the overcrowding of teeth and an upper dental arch that is narrowed with overlapping incisors.  The enamel of teeth will be poor if the individual has been zinc deficient during the period of tooth formation.  In zinc deficiency, the fingernails are white and spotted, opaquely white and tissue paper thin in most cases.  The very thinness of the nails, when combined with anxiety, leads to active nail biting.  Other areas that can benefit and respond from zinc supplementation are acne, eczema and herpes simplex (cold sores).  Individuals suffering from allergies can also benefit from supplementing with vitamin C, zinc and pantothenic acid.