There has been conflicting evidence about the protective effects of vitamin E on cancer. One reason for this seems to be that while vitamin E may act as an antioxidant and reduce mutations that lead to cancer, for already formed cancer cells vitamin E may confer its antioxidant activity to the cancer cells and actually protect the cancer. And some studies have shown that vitamin E supplementation was not effective in the prevention of cancer. A potential problem with these studies, however, is that they were evaluating dl-alpha tocopherol acetate, a synthetic form of vitamin E. Not all forms of vitamin E interact the same way in the body. Some researchers believe that the synthetic form may slow down the antioxidant function by taking binding sites that would have been available for natural E, d-alpha tocopherol.
However, a form of vitamin E known as vitamin E succinate (alpha tocopheryl succinate) actually targets cancer cells with its own special attack. It triggers the production of free radicals inside cancer cells, triggering cell death, while being non toxic to healthy cells. Clinical trials are showing this advantage of succinate that other vitamin E forms did not seem to have. Vitamin E succinate does not have antioxidant activity of its own, but during the digestive process, some succinate is enzymatically converted to d-alpha tocopherol, which does have antioxidant activity.
So if you are going to supplement with vitamin E, you may want to consider using the succinate form. 400 IU is currently being recommended in light of these newer insights on vitamin E.
summarized from “Vitamin E Succinate continues to show impressive Anti-Cancer properties”, Dr. James Meschino, Acupuncture Today, March 2016.