What does Vitamin E do?

Vitamin E is an antioxidant that protects cell membranes and other fat-soluble parts of the body, such as low-density lipoprotein (LDL; “bad” cholesterol) cholesterol, from damage.

Only when LDL is damaged does cholesterol appear to lead to heart disease, and vitamin E is an important antioxidant protector of LDL.¹ Several studies,^{2 3} including two double-blind trials,^{4 5} have reported that 400 to 800 IU of natural vitamin E per day reduces the risk of heart attacks. Other recent double-blind trials have found either limited benefit⁶ or no benefit at all from supplementation with synthetic vitamin E.⁷ One of the negative trials used 400 IU of natural vitamin E⁸ —a similar amount and form to previous successful trials. In attempting to make sense of these apparently inconsistent findings, the following is clear: less than 400 IU of synthetic vitamin E, even when taken for years, does not protect against heart disease. Whether 400 to 800 IU of natural vitamin E is, or is not, protective remains unclear.

Vitamin E also plays some role in the body’s ability to process glucose. Some, but not all, trials suggest that vitamin E supplementation may eventually prove to be helpful in the prevention and treatment of diabetes.

In the last ten years, the functions of vitamin E in the cell have been further clarified. In addition to its antioxidant functions, vitamin E is now known to act through other mechanisms, including direct effects on inflammation, blood cell regulation, connective tissue growth, and genetic control of cell division.⁹