Vitamin E is a drug that is heavily used by many doctors and patients in clinical practice. It is mainly because vitamin E has been found to have antioxidant effects through animal experiments and clinical observation tests. Therefore, proper supplementation of vitamin E helps to delay aging and prevent diseases such as cardiovascular and cerebrovascular diseases and tumors, and is believed to lead to longevity, so it is widely used in clinical practice. However, how can vitamin E be used to achieve beneficial therapeutic effects? Are the doses we usually use reasonable? A meta-analysis published in Ann Intern Med by Professor Miller et al. in the United States included 19 randomized controlled clinical trials, including 9 reports of taking vitamin E alone and 10 reports of taking vitamin E-containing multivitamin tablets; the total number of study subjects was 135,967. The results showed that vitamin supplementation with 150 IU/d produced no adverse effects and was beneficial to health. In contrast, the risk of death increased dose-dependently when supplementing with vitamin E; 150 IU/d, and significantly increased mortality at 400 IU. Professor Miller concluded that vitamin E when ingested in high doses has increased anticoagulant activity, may no longer have antioxidant activity, and can impede the absorption and function of other fat-soluble vitamins. Nutrition experts suggest that the daily intake of vitamin E should be about 10-20 mg (15-30 IU), and we can get sufficient amount of vitamin E from normal diet such as vegetable oil, green leafy vegetables and nuts every day, so there is no need for vitamin E supplementation. According to Professor Jiang Zhuming, the chief expert of the Parenteral Nutrition Center of Peking Union Medical College Hospital, from the perspective of evidence-based medicine, this study is the latest research on whether vitamin E is beneficial to patients, and proposes that taking high doses of vitamin E is harmful, which has important reference significance for the majority of clinicians and patients.