The antioxidant role of selenium protects the heart from free radicals. A healthy immune system requires adequate levels of selenium, and moderate doses of supplemental selenium might enhance immunity. Selenium protects the body from heavy metal contamination. This mineral is needed for normal development of the fetus during pregnancy. Typical daily intakes of this mineral are 100mcg. for men and 70mcg. for women.
Selenium can cause side effects when taken in excessive amounts.
Symptoms of toxicity include liver damage, hair loss, heart problems, diseased teeth, nausea, diarrhea, irritability, and fatigue. Daily selenium intake should be limited to 200mcg. The amount of selenium in foods varies depending on the mineral content of the soil in which they were grown. The best dietary sources of selenium are organ meats, seafood, beef, whole grain breads and cereals, and milk. As a supplement, the organic forms of selenium called selenomethionine and selenium-rich yeast are better absorbed than the inorganic form called selenate.