The March 16, 2005 issue of JAMA published the results of the large, long RCT that gave 400 U. Of Vitamin E to the study participants. (The HOPE and HOPE TOO trials)
No protection for heart disease or cancer was evident. The promising biological plausibility of Vitamin E as an anti-oxidant has been countered with very strong data indicating it does not protect against the diseases that we thought it might. I remember telling patients it looked like a good play and I have bought many bottles myself. At worse it seemed harmless. It may be harmless but the HOPE trialists report data that suggest possible increased risk of heart failure. The data there seems about as weak as the data we used to tout E in the past, so I don't plan to scare anyone with that.
But if true is this still another example of how we get things just backwards?. We recommended HRT to decrease heart attack risk and later learned it increases risk of another vascular disease, stroke. We knew that if you gave a person with CHF beta-blockers it would make it worse and now they are required treatment of CHF. We excluded anti-cholinergics for COPD ex cathedra because they would make secretions too thick. The list of "getting things backwards" is so easy to make that it is not fun anymore. All of this needs to be included in the "anti-hubris" lectures to medical students.