Optimum Zinc is a dietary supplement based on Zinc, Vitamin C, Vitamin D3, Echinacea, and Selenium. Echinacea supports the body’s natural defenses. Zinc contributes to protect cells from oxidative stress and to the normal function of the immune system. It is an effective antioxidant, playing a crucial role in the body’s defense mechanism against free radicals; it also helps to maintain a normal immune function by stimulating the activity of lymphocytes, increasing interferon levels and antibody response. Vitamin D3 contributes to maintain healthy bones and normal muscle function, favours normal absorption and use of calcium and phosphorus and healthy functioning of the immune system. Selenium contributes to protect cells from oxidative stress.