Fish, shellfish , red meat, grains, eggs, chicken, liver, and garlic are all good sources of selenium. The amount of selenium in vegetables is dependent on the selenium content of the soil. Selenium has a variety of functions.
Selenium also seems to stimulate antibody formation in response to vaccines.
It also may provide protection from the toxic effects of heavy metals and other substances. It may assist in the synthesis of protein , in growth and development, and in fertility, especially in men. Selenium has been shown to improve the production of sperm and sperm motility. There is no recommended daily allowance for selenium. The suggested intake by nutrition experts is 50 to 200 micrograms, which the average diet in the U.S. usually provides.