"Selenium as a potential chemosensitizer for cancer therapy has attracted some attention lately"
See article The selenium gold mine
September 2006 Function Foods and Nutraceuticals Magazine Q&A with leading experts in the field of selenium There are links at the end of this article to the literature of the use of selenium with cancer.
Although it is toxic in large doses, selenium is an essential micronutrient in all known forms of life. It is a component of the unusual amino acids selenocysteine and selenomethionine. In humans, selenium is a trace element nutrient which functions as cofactor for reduction of antioxidant enzymes such as glutathione peroxidases and thioredoxin reductase. It also plays a role in the functioning of the thyroid gland by participating as a cofactor for thyroid hormone deiodinases . Dietary selenium comes from cereals, meat, fish, and eggs. The recommended dietary allowance for adults is 55 micrograms per day. Liver and Brazil nuts are particularly rich sources of selenium. A list of selenium rich foods can be found on The Office of Dietary Supplements Selenium Fact Sheet.