To the study in question. Researchers looked at 19 previous studies dating back to 1966. The grand total of patients involved in these trials eclipsed 135,000. They found a startling statistic: death from any cause progressively increased if the vitamin dose was greater than 150 international units (IU) a day. This level is well below the tolerable upper intake for vitamin E, set at 1,000 mg of any form or 1,500 IU of natural vitamin E a day.
But these authors concluded that “high-dosage (greater than 400 IU a day) vitamin E supplements may increase all-cause mortality and should be avoided.” One point that doesn’t get a lot of press is that the patients enrolled were older and already had chronic diseases — thus already were at greater risk of mortality.
Also in 2005, Canadian researchers reported a high risk of heart failure for those taking 400 IU a day of vitamin E compared to placebo. Their study group comprised 4,000 adults over 55 with either heart disease or diabetes. In the U.S., about 11% of people consumed at least 400 IU of vitamin E a day through supplements. And, as we get older, we seem to take more.
My bottom line: even though early observational studies showed that high intakes of vitamin E are linked to lower risks of heart disease, better quality trials did not confirm this. Now recent evidence shows that a high dosage of vitamin E (i.e. over 400 IU a day) is associated with higher all-cause mortality.
It would be my suggestion to avoid taking vitamin E supplements directly, but instead to get the nutrient through a standard multivitamin — set at a level lower than 400 IU.
To read my previous article in this series, click here.