Superoxide Dismutase Superoxide dismutase (SOD) is an enzyme that occurs naturally in a variety of food sources, including alfalfa, barley grass, broccoli, Brussels sprouts, cabbage, wheatgrass, and most dark green plants. As powerful as they are, enzymes cannot act alone. They require adequate amounts of other substances, known as coenzymes, to be fully active. Among the most important coenzyme factors are the B-complex vitamins, vitamin C, vitamin E, and zinc. |