Chemical Symbol



Selenium in another trace mineral found in the body, it’s relatively new being discovered in the 1970’s. It functions in the body as a part of the antioxidant enzyme system that defends the body from free radical formation.


Selenium is part of the enzyme glutathione peroxidase and acts as an antioxidant. It helps to protect the red blood cells and cell membranes from free radical damage like UV light. Selenium has been shown to help improve the production of antibodies and help strengthen the bodies’ surveillance of caner of abnormal cellular growth. Lastly thyroid hormones need a selenium based enzyme in order for them to begin to metabolize.

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Recommended Intake


  • Up to 6 months: 15 micrograms (mcg)
  • 7 to 12 months: 20 mcg

These values are Adequate Intake (AI) values


Children and Adolescents

  • 1 to 3 years old: 20 mcg
  • 4 to 8 years old: 30 mcg
  • 9 to 13 years old: 40 mcg
  • 14 to 18 years old: 55 mcg



  • 19 to 50 years old: 55 mcg
  • 51 years old and older: 55 mcg



  • Pregnant: 60 mcg
  • Lactating: 70 mcg


Most of the cases of selenium deficiency have only been seen in those who eat foods that are grown in soil that is selenium deficient. A severe deficiency of selenium leads to the heart disorder called Keshan, a potentially fatal cardiomyopathy that affects young children in areas of rural China with low selenium. You may also see selenium deficiencies related to other disorders that are seen in alcoholics and those who consume mostly processed foods. Blood selenium levels can also been seen in those with HIV/AIDS, fibrocystic breast disease, Down syndrome and patients with liver disease.

Sources in the Diet

Some good sources of selenium include Brazil nuts, tuna, flounder, salmon, pasta, oysters, dark turkey meat, pork chops and wheat germs.

Recent Studies and Articles

Benefits of selenium

Research for health and disease prevention

Selenium and preventing cancer

Challenges Presented

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  1. [] – Reavley N. The New Encyclopedia of Vitamins, Minerals, Supplements and Herbs. New York, NY: M. Evans and Company, Inc.; 1998.
  2. [] – Nelms, M. Sucher, K. Lacey, K. Roth, S. Nutrition Therapy & Pathophysiology. 2 ed. New York, NY: Cengage Learning; 2011.
  3. [] – Boyle, Marie A. and Anderson Sara L. Personal Nutrition. 7th ed. Belmont, CA: Wadsworth/Thomson Learning; 2007.
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