Vitamin E

Publication Date: 
Tue, 11/08/2011
By: Alere Staff

Vitamin E is the name for a group of fat-soluble compounds with antioxidant qualities, which protects cells against the effects of free radicals.1 Free radicals, or molecules with an unshared electron, reacts with oxygen to form reactive oxygen species (ROS). Vitamin E stops the production of ROS formed when fat undergoes oxidation.2

Vitamin E plays a key role in the body and is being studied in3:

  • Heart disease
  • Cancer
  • Eye disorders
  • Cognitive decline

Where is Vitamin E found?

Several foods provide vitamin E, including nuts, seeds and vegetable oils are among the best sources, and there are also considerable amounts found in leafy green vegetables and fortified cereals.4 Dietary supplements are also a source of vitamin E, although there is no proven medicinal uses of vitamin E supplementation beyond the recommended daily allowance recommended by the U.S. Food and Drug Administration.

Interaction with Warfarin

Recent concerns have been raised about the safety of vitamin E supplementation, particularly in high doses. Vitamin E supplements have the potential to interact with several types of medications, including warfarin. "Vitamin E can inhibit platelet aggregation and antagonize vitamin K-dependent clotting factors."5 As a result, vitamin E can affect INR levels in patients taking warfarin.  

More frequent monitoring of your INR may be neccessary if you are taking vitamin E supplements. As always, discuss all diet and supplementary supplements with your doctor.

  1. Traber MG. Vitamin E. In: Shils ME, Shike M, Ross AC, Caballero B, Cousins R, eds. Modern Nutrition in Health and Disease. 10th ed. Baltimore, MD: Lippincott Williams & Wilkins, 2006;396-411.
  2. Verhagen H, Buijsse B, Jansen E, Bueno-de-Mesquita B. The state of antioxidant affairs. Nutr Today 2006;41:244-50. 
  3. Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.
  4. U.S. Department of Agriculture National Nutrient Database.
  5. Corrigan JJ Jr. The effect of vitamin E on warfarin-induced vitamin K deficiency. Ann N Y Acad Sci. 1982;393:361-8.