The human body is resilient and at the same time, so fine-tuned that it adapts itself to different conditions by adjusting to the changes brought by the onslaught of unknown chemicals and other foreign bodies. It reacts to the same substance differently according to the quantity. In medical terms, dose is defined as the amount of a prescribed drug taken under the supervision of a medical practitioner for certain conditions in the body.Overdose of a drug happens when it is taken exceeding a threshold, setting negative reactions in the body. This situation is corrected only when the drug intake is stopped or by taking alternate medicines under the consultation of medical practitioner to subside the effects.

Vitamin E is a powerful antioxidant that helps fight against the damage caused by free radicals. As vitamin E foods are fat soluble, even high amounts of vitamin E cant be taken without increasing the cholesterol intake, leading to higher chances of cardio-vascular diseases. A vitamin E supplement can be taken as an over-the-counter drug, which means it can be bought without a prescription, and the Food and Nutrition Board of the Institute of Medicine has set tolerable Upper Intake level of alpha-tocopherol at 1,000 mg of for adults 19 and older and decreased quantities for other age groups. Exceeding these limits may be toxic to the body.

A meta-analysis that combined the results of 19 clinical trials of vitamin E supplementation for various diseases, including heart diseases, reported that the increased risk of death was associated with a level of 2,000 IU per day. Also, a few side effects have been noted in adults taking less than 3,000 IU of alpha-tocopherol daily.

There is no conclusive evidence for the Upper Intake Level of vitamin E and hence the level is a recommended one. It would be useful to note that in the normal concentrations found in the body, vitamin C and beta-carotene are antioxidants, but at higher levels, become pro-oxidants. It is not known whether the same applies for vitamin E. Hence, the recommendation for utilizing vitamin E for disease prevention is to take many servings of vegetables and fruits and not to over-supplement.