Ultra Cruz Equine Antioxidant Formula is a potent selenium, vitamin C and vitamin E powder formulation that supports healthy tissues and organs. Competition Horses have a high energy demand in order to perform their events, and their Muscle cells require a large amount of antioxidants. Selenium and vitamin E are key antioxidants that work well together to regulate free radicals produced during Exercise. While selenium is active within the cell, vitamin E (d-alpha-tocopherol Acetate), acts within the cell membrane. Selenium also supports a healthy immune system while providing the Horse with necessary Muscle and joint support. Vitamin E, a fat-soluble vitamin, has been implicated as a cofactor in glucose production and supports a healthy immune system. Vitamin C is an antioxidant that works with vitamin E to protect the tissues of the body, especially those of the respiratory system. Vitamin C also supports production of connective tissues like tendons and ligaments as well as skin, hooves, bones and teeth.