Selenium yeast: Composition, quality, analysis, and safety*
G. N. Schrauzer
Department of Chemistry and Biochemistry, University of California, San Diego, and Biological Trace Element Research Institute, Chula Vista, CA 91914, USA
Abstract: Selenium yeast, produced by growing select strains of Saccharomyces cerevisiae in Se-rich media, is a recognized source of organic food-form Se, but the determination of its exact composition with respect to the Se species present produced conflicting results. Improved methods of analysis have since revealed it to contain 90+ % of its Se in the form of selenomethionine, the principal organic nutritional form of Se for higher animals and humans. The safety record of Se yeast is excellent: During the three decades of its world-wide use as a source of supplemental Se, no cases of Se poisoning have occurred due to dosage or formulation errors.
Keywords: selenium; selenium yeast; Saccharomyces cerevisiae; selenomethionine; supplemental selenium; selenium poisoning.
*Paper based on a presentation at the 2nd International Symposium on Trace Elements in Food (TEF-2), Brussels, Belgium, 7-8 October 2004. Other presentations are published in this issue, pp. 65-143.