Zinc is mineral. It is considered to be an essential nutrient, meaning that the body cannot produce or store it. Therefore, we must get a constant supply through our diet or supplements. It plays a variety of vital roles in many functions in the body including cell growth and division, energy production, immune function, DNA and protein synthesis, cognitive function, fertility and reproduction, the maintenance of normal testosterone levels, bones, hair, nails and vision, and vitamin A metabolism. It also contributes to growth and tissue repair, and the protection of cells from oxidative stress.