Zinc is a mineral that is needed for healthy functioning of the body's immune system. Zinc supplementation has been shown to reduce the severity and duration of common cold symptoms. One way to approach this question is to look at what happens to the body if we were to eliminate or drastically reduce our consumption of zinc.
Some people do, in fact, have a hereditary zinc deficiency.
An increase in the number and frequency of infections results. All of these symptoms are reversible upon sufficient administration of zinc. Other problems resulting from zinc deficiency include impaired protein synthesis and energy production, poor collagen formation, poor alcohol tolerance, loss of taste and smell, and many pregnancy related problems. Zinc is not only necessary for healthy functioning of your body, but by bolstering the immune response, supplementation of zinc definitely reduces cold and flu symptom severity and duration. If you do not consume red meat you are at risk of zinc deficiency.