Toxicity of Selenium in Brazil Nuts to Rats

Nuts from Bertholletia excelsa, commonly known as Brazil nuts, were analyzed for selenium. Of 529 nuts from one commercial source, 6% were found to contain 100 ppm selenium or more. The mean value for all nuts was 29.6 ppm and the median value was 13.4 ppm. Hexane extracted high-selenium Brazil nut meal in a corn-based diet fed to rats produced toxicity similar to that obtained from seleniferous corn, selenomethionine or sodium selenite as assessed by weight gain, visually scored liver damage, and liver, kidney, and spleen weights. Selenium contents of liver, kidney, spleen, and blood were also determined. It is suggested that the selenium in Brazil nuts is as biologically potent as that from other sources.