Selenium may only be found in trace amounts within the human body, but this mineral is essential for many bodily functions. Not only does it work to rid your cells of damaging free radicals, but it also keeps your immune system working properly and may even prevent certain diseases. Talk to your doctor about meeting your RDA of selenium before taking supplements or adding more of it to your diet.
Antioxidant
Free radicals can wreak havoc on your body in many ways, from increasing the rate at which you age to contributing to the development of heart disease and cancer. Selenium acts as an antioxidant, eliminating these harmful substances from your body. It works by creating proteins known as antioxidant enzymes, which neutralize the free radicals and thereby prevent the damage they can impart on your body. Selenium is a particularly effective antioxidant when combined with vitamin E.
Immune Health and Other Functions
Your thyroid requires selenium to function properly, as does your immune system. This mineral helps to keep your white blood cell count up and thereby wards off infections and illnesses. According to MedlinePlus, some studies suggest that selenium may help prevent cancer and heart disease, and it may even increase male fertility. However, more studies are needed to determine the extent to which selenium is effective in these areas.
Deficiency and Overdose
While selenium is essential for the human body, taking too much or too little can have negative repercussions. It is rare for someone to have a selenium deficiency in the United States, unless that person has been fed through an IV for an extended period of time. If you take birth control pills, have a malabsorption condition, smoke cigarettes or drink alcohol, you may also be at risk for developing a deficiency. However, taking too much selenium can result in a condition called selenosis, which is characterized by hair loss, nausea, irritability and fatigue. But this is rare in the developed world as well.
RDA and Sources
Both men and women need 55 mg of selenium a day, and if you eat a balanced diet, you should be able to get this amount through food alone. Good dietary sources of selenium include wheat germ, brewer's yeast, butter, shellfish, whole grains, sunflower seeds, garlic and liver. However, the more processed your food is, the less selenium it will contain. Selenium levels in food are also determined by the amount in the soil they were grown in, or in the case of animal foods, the amount in the grain the animals consumed. This mineral is also available as a supplement, but talk to your doctor before taking one.
