From what I have read of the studies and recommendations by experts is that taking 200 IU every day is safe. The reasons for taking it are not solidly proven (the potential to help prevent macular degeneration, prostate cancer, and Alzheimers disease for example) but some experts say in light of the safety at the 200 IU daily level "why not?" According to John Swartzberg, M.S., Chair of the Editorial Board of the Univ. of CA @ Berkely Wellness Newsletter: "There's no solid evidence of harm (at the 200 - 400 level) and some benefits may yet pan out. Other important studies on E are still underway. Meanwhile, eat foods rich in E- nuts, seeds, vegetable oils, whole grains, and leafy greens."
Hope that helps in your decision making.
Sue Gilbert, M.S., Nutritionist at iVillage.com