Optimal Dose Of Vitamin E Maximizes Benefits, Minimizes Risk (Medical News Today) Vitamin E has been heralded for its ability to reduce the risk of blood clots, heart attack, and sudden death. Yet in some people, vitamin E causes bleeding. Scientists have known for more than 50 years that excess vitamin E promotes bleeding by interfering with vitamin K, which is essential in blood clotting. However, they haven't been able to pinpoint how the two vitamins interact. [News Source]