To the Editor.
—I have questions regarding the article by Clark et al.1 Other selenium studies I have read generally use generic forms of selenium: selenomethionine or sodium selenite. The study by Clark et al1 uses a commercial product: high-selenium yeast tablets from Nutrition 21. Nutrition 21 manufactures selenium supplements for distribution to health food stores. The use by Clark et al of Nutrition 21 selenium tablets could be interpreted as an endorsement. Already Nutrition 21 distributors are citing the study by Clark et al in sales promotions for Nutrition 21 selenium tablets. An independent chemical supplier could have made up selenomethionine tablets for this study, thereby avoiding commercial involvement.Many people cannot tolerate even small amounts of yeast. This fact may have caused the gastrointestinal upset that led some of the research subjects to withdraw from the study.The study by Clark et al states that 200 μg of selenium
Parker JS. Selenium Supplementation and Cancer Rates. JAMA. 1997;277(11):880-881. doi:10.1001/jama.1997.03540350030017