A controversial new study has found taking high doses of vitamin E may increase a person's overall risk of death in any given year. Although researchers really don't know how vitamin E causes death, they suggest people should stop taking high doses of the popular supplement.
Current dietary guidelines set a high upper limit of 1,500 IU a day, and a large majority of the 25 percent of adults who take vitamin E supplements do so in large doses, greater than 400 IU per day.
After studying data on dosage levels and death rates of some 136,000 people in 19 countries, scientists found the mortality rate within five years rose by about 5 percent in the 11 trials with vitamin E doses of at least 400 IU per day. However, the effect of low-dose supplements lowered the risk of death by less than 1 percent.
Their theories about why high amounts of vitamin E may be harmful:
- Because vitamin E is an anti-coagulant, it may increase the risk of bleeding which contributes to strokes in patients already taking blood-thinners.
- Taking doses irregularly.
- Vitamin E could become a free radical at high doses, damaging the very proteins and fats it usually protects.
- The type of vitamin E found in supplements could displace other antioxidants, including another form of vitamin E found in many foods, disrupting the balance of antioxidant systems.
While I don't recommend many supplements, vitamin E is a currently an exception. I certainly might change my mind about this in the future, but currently it seems a reasonable supplement to take, especially if you are a protein type. The optimum dose of vitamin E you should take varies widely, from 100-800 units per day, depending on your nutritional type, and about half as much as the high upper limit cited earlier.
Nevertheless, I must admit that I vacillate on this issue as I am a protein type and I haven't taken any vitamin E for many months. I have taken it for many decades, but the more I study the more I wonder about supplementation.
New Scientist November 10, 2004