A study in the British Medical Journal found that vitamin E increased the risk of a hemorrhagic stroke by 22-percent. That type of stroke involves bleeding in the brain.
Researchers do not know at what level the vitamin becomes harmful. Hemorrhagic strokes are the least common type and occur when a weakened blood vessel ruptures and causes brain damage.
Researchers also found that vitamin E could actually cut the risk of ischemic strokes by 10-percent.