Zinc contributes to normal: DNA synthesis, acid-base metabolism, carbohydrate metabolism, cognitive function, fertility and reproduction, macronutrient metabolism, metabolism of fatty acids, metabolism of vitamin A, protein synthesis. Zinc contributes to the maintenance of normal bones, hair, nails, skin, vision and testosterone levels in the blood. Zinc contributes to the normal function of the immune system. Zinc contributes to the protection of cells from oxidative stress. Zinc has a role in the process of cell division.