CHPA Comments on Vitamin E Meta-Analysis Conclusions

Cites limitations that give rise to questions of applicability

Washington, D.C. (December 6, 2004)—The Consumer Healthcare Products Association called into question a recent article published online in the Annals of Internal Medicine, entitled, “ Meta Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality.” The paper represents an analysis of the results from several clinical studies involving the use of vitamin E.

CHPA noted the following limitations in this analysis that give rise to questions of applicability of these findings to the general population:

  1. First, a majority of the study participants were middle- to older-age and at high risk for chronic disease, including coronary heart disease.
  2. Only three of the 19 studies evaluated in the meta-analysis evaluated the effects of vitamin E alone, while in the remaining 16 studies, vitamin E was used in combination with other vitamins, minerals, and/or prescription medications.
  3. The higher dosage trials were smaller on average compared to all trials and represented less than one-third of the total number of participants analyzed.
  4. The writers indicate that precise identification of the threshold at which risk increases is difficult to determine.

Based on these limitations, in addition to conflicting recommendations from the National Academy of Science Institute of Medicine’s Panel on Dietary Antioxidants, University of California-Davis Professor of Internal Medicine and Pathology, Dr. Ishwarlal Jialal echoed this sentiment,   “It is premature to draw conclusions from this study that high dose vitamin E supplementation is risky.  Results of this meta-analysis should not be generalized to a healthy adult population because many of the studies that used high doses of vitamin E included populations with such concomitant chronic diseases as early Parkinson’s, Alzheimer’s, and cardiovascular disease.” Jialal added, “Both the statistical approach and the exclusion of studies in which there were fewer than ten deaths is highly questionable.”

Contacts: Elizabeth Assey and Virginia Cox, 202.429.9260

CHPA is the 123-year-old trade association representing U.S. manufacturers and distributors of over-the-counter medicines and nutritional supplement products.