For which of the following has the cytoxic effect of vitamin on human lymphocytes in vitro at high concentration been repoed -

VITAMIN E (Tocopherol) Vitamin E is the generic name for a group of closely related and naturally occurring fat soluble compounds, the tocopherols. Of these alpha-tocopherol is biologically the most potent. Vitamin E is widely distributed in foods. By far the richest sources are vegetable oils, cotton-seed, sunflower seed, egg yolk and butter. Foods rich in polyunsaturated fatty acids are also rich in vitamin E. The usual plasma level of vitamin E in adults is between 0.8 and 1.4 mg per 100 ml. While there is no doubt that man requires tocopherol in his diet, there is no clear indication of dietary deficiency. The role of vitamin E at the molecular level is little understood. The current estimate of vitamin E requirement is about 0.8 mg/g of essential fatty acids. This roughly works out to 8-10 mg tocopherol per day depending on the edible oil used. Recently the cytotoxic effect of vitamin E on human lymphocytes in vitro at high concentrations has been repoed. This being so, caution should be exercised against the mega-dose consumption of vitamin E in clinical practice. Ref : Park 25th edition Pgno : 657