Ultra A-O is a potent antioxidant supplement that includes vitamins and other nutrients that effectively participate in our body's antioxidant defence systems. Vitamin E is recognized as the body's most valuable fat soluble antioxidant. It prevents the oxidation of unsaturated fatty acids by inactivating free radicals, thus stabilizing and protecting cell membranes. Vitamin C is a potent water-soluble antioxidant nutrient that is also essential for bone metabolism and immune function. When neutralizing free radicals inactivates vitamin E, vitamin C regenerates it back to full activity. Glutathione is a naturally occurring tripeptide and a major component of two anti-free radical enzymes, glutathione peroxidase and glutathione reductase. As such, glutathione scavenges toxic free radicals and inhibits peroxidation thereby slowing down free-radical catalyzed chain reactions. Glutathione can also reactivate (reduce) oxidized vitamin C and is dependent on selenium and B vitamins for its effectiveness. Similarly, zinc maintains the activity of the antioxidant enzyme superoxide dismutase. N-acety-L-Cysteine is a precursor for the sulfur amino acid cysteine, which is used by cells to synthesize glutathione. Supplementation with N-acety-L-Cysteine is recognized as a safe and highly effective method of increasing intracellular glutathione stores.