Selenium – A Powerful Antioxidant

Selenium – A Powerful Antioxidant
Selenium is a micromineral and a powerful antioxidant which protects your body from damaging free radicals. It also acts in a protective capacity throughout the body. In this article I will be discussing this nutrient in greater detail and providing you with a summary of its main functions, the best food sources, the recommended daily allowances (RDAs) and the potentially adverse effects of consuming too much or too little.


Selenium was discovered in 1818 by two Swedish chemists Jons Jakob Berzelius and J. G. Gahn who were studying the chemicals within sulphuric acid. During their studies they discovered that these chemicals contained a new element which became known as selenium.


The main role of selenium in the human body is to act in a protective role as an antioxidant. It protects the body from oxygen related damage, prevents certain types of cancer, prevents heart disease, prevents joint inflammation and reduces the symptoms of arthritis. This nutrient has also been linked with potentially slowing the progression of the human immunodeficiency virus (HIV) although more research is needed to confirm this suggestion.

3) RDA:

You need to consume more selenium as you get older. Children aged between 0 and 6 months are advised to consume 0.015 milligrams (mg) of this nutrient each day. This requirement increases to 0.04mg per day for children aged between 9 and 13 years. The RDA for adults aged 14 years and older is 0.055mg per day. The tolerable upper limit (TUL) for this nutrient is 0.4mg per day.


Nuts and fish are two of the best selenium foods. Some of the richest sources include Brazil nuts (1.92mg per 100g), mixed nuts (0.42mg per 100g), salmon (0.038mg per 100g) and shrimp (0.048mg per 100g).


Selenium overdoses are normally the result of excessive supplement consumption. When an overdose does occur it is referred to as selenosis. The symptoms of selenosis include bad breath, fatigue, gastrointestinal problems, irritability, mild nerve damage and white blotchy nails.


Dietary selenium deficiencies are very rare and are normally only observed in countries where the soil has a very low selenium concentration. Intravenous feeding and serious gastrointestinal problems can also cause a deficiency. The symptoms of deficiency include Kashin-Beck disease (a bone and joint disorder), Keshan disease (a heart disorder), myxedematous endemic cretinism (a disease that causes mental retardation) and osteoarthritis (the chronic breakdown of cartilage in the joints).

Tom Parker owns Free Fitness Tips – a fantastic source of free, impartial fitness advice. You can learn more about selenium and the other microminerals by visiting his website.