Selenium is an essential mineral that works as part of an antioxidant enzyme. The body only needs a tiny amount of selenium. The amount is measured in micrograms (mcg). The highest levels of selenium in the body are found in the liver, kidney, heart, and spleen.
Scientists are studying a possible link between cancer and low selenium intake. People who have liver cancer seem to have lower levels of selenium than people who have healthy liver function. People who have breast cancer also have lower levels of selenium than do healthy subjects. In theory, selenium protects against both cancer and heart disease. This is because it is an antioxidant.
The adult recommended daily allowances, called RDA, for selenium are:
Getting too much selenium is not healthy either. High levels of selenium can cause any of all of the following problems: