The orally bioavailable delta form of the naturally-occurring fat-soluble vitamin E, mostly found in soybean and corn oils, with potential antioxidant activity. Although the exact mechanism of action of this tocopherol has yet to be fully identified, delta-tocopherol appears to have the ability to scavenge free radicals, thereby protecting cells against oxidative damage. Check for active clinical trials using this agent. (NCI Thesaurus)