The best sources for trace element selenium are brazil nuts, tuna and oysters; although there is more in one ounce of brazil nuts than in nine ounces of tuna (Higdon et al, 2001, Sources).
Selenium is an important component of the enzymes of the body, these enzymes can be found in the nose, thyroid, testes, and more. In the thyroid, selenium is part of iodothyronine deiodinase. The thyroid gland makes two types of hormones pertinent to this selenium dependent enzyme, triiodothyronine and it's in-active counterpart thyroxine. Only small amounts of triiodothyronine are created, so iodothyronine deiodinase works to activate thyroxine by removing an iodine and effectively turning it into triodothyronine. This same enzyme has