Natural Factors Clear Base Vitamin E is the purest natural E (d-alpha tocopherol) available. Superior benefits of Clear Base Vitamin E: It is the purest and most potent form of d-alpha tocopheryl available on the market. Clear Base Vitamin E is the result of a careful extraction process which gives a clear vitamin E oil, thus the name Clear Base. There are no added oils, diluents or other tocopheryls, just alpha tocopheryl. It is this therapeutic form of vitamin E that obtained the remarkable results at the Shute Institute in research projects that showed the importance of vitamin E in heart health and general wellbeing. World-renowed vitamin E researchers, Ingold and Burton, used Clear Base vitamin E to obtain their results. Most natural-source vitamin E products are already 1.36 times more bioavailable than their synthetic counterparts but as indicated by the Ingold and Burton study Clear Base Vitamin E is 1.8 times more bioavailable than synthetic vitamin E. Clear Base vitamin E is a therapeutic form of vitamin E to use when targetting specific ailments. It is sold only in natural food stores.