Though not a macromineral, zinc is important for all the organs. It is a trace mineral, essential for more than 30 enzyme reactions that feed into a variety of homeostatic functions. Zinc is located at the active site of superoxide dismutase (SOD), a major protective antioxidant enzyme, and zinc-dependent enzymes are involved in growth, immunity, and tissue renewal. Zinc citrate occurs naturally in breast milk. This form of zinc is well-tolerated and well-absorbed. This nutrient is the purest obtainable.