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1) Should vitamin E be avoided because it increases the risk of death?
2) Should one stop taking vitamin E because study has shown that vitamin E increases heart failure risk and doesn't help protect against heart disease or cancer?
These questions were raised after a meta-analysis of vitamin E studies from Johns Hopkins University was presented at the American Heart Association meeting. The findings of this study was released November 10, 2004 on line in the Annals of Internal Medicine and appeared on the front page of USA Today and numerous other national media.
In fact:
The meta-analysis studies was not a controlled trial that was designed to determine if supplementation with vitamin E increased the risk of death, but rather a meta-analysis, in which previously published studies are reviewed to answer a question not previously asked or fully investigated in the original studies. Meta-analyses cannot give definitive answers or establish cause and effect relationships. A meta-analysis is limited by the different designs and limitations of the individual studies and can be skewed by the findings of one or two studies.
The vitamin E typically used in these studies was only the synthetic dl-alpha-tocopherol and not the natural form of vitamin E (d-alpha-tocopherol) and also without other 3 tocopherols (beta, delta and gamma Tocopherols) or tocotrienol that are part of the vitamin E family. These factors may have played a role in the findings, as we know that there are significant differences in the biochemistry of alpha and non-alpha-tocopherol as well as important differences between natural and synthetic vitamin E.
Patients that were involved in the meta-analysis studies were generally either not healthy (had a pre-existing condition) or were at a significantly increased risk of developing the disease that was being investigated in the respective study. This certainly could have impacted the findings. Consequently, it becomes very difficult to generalize the findings of the meta-analysis to a healthy population.
Numerous clinical studies have shown benefits from supplementing with vitamin E. The upper safe limit for vitamin E intake is set at 1,600 IU/day for normal healthy adults by the Institute of Medicine.
The conclusion from this meta-analysis study that vitamin E supplementation should be discontinued is irresponsible and unfounded.
It is safe to take supplemental vitamin E in doses up to 400 IU a day. Avoid the synthetic form of vitamin E (dl-alpha-tocopherol).
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