Selenium is a trace mineral essential to good health and nutrition. According to Oregon State University's Linus Pauling Institute, most Americans get more than adequate amounts of selenium from their daily diet. To make sure that you get adequate amounts of selenium, eat a varied diet that includes foods rich in this mineral. Talk to your doctor before taking selenium supplements or other dietary supplements to address specific health concerns.
Selenium Uses
Selenium is known as an antioxidant. It helps your body make glutathione peroxidase, which works in concert with vitamin E to protect your cells from damage inflicted by free radicals produced by your body or that occur due to exposure to smoke, pollution and radiation. Most people get 100 mcg of selenium from the foods they eat --- more than a sufficient amount, says the Linus Pauling Institute. Selenium supplements are primarily used to prevent selenium deficiency, but they have a variety of other purported uses, the primary being cancer prevention, states Tufts Medical Center. However, people take selenium supplements to address complications related to diabetes, depression, acne, anxiety, gout, fibromyalgia, heart disease, hypothyroidism, arthritis and multiple sclerosis.
Dosages and Safety
MayoClinic.com indicates that the dosage of selenium used to address deficiencies ranges from 10 to 70 mcg selenium daily, depending on age, gender and if the patient is pregnant or breastfeeding. Clinical trials that studied the use of selenium for various health issues typically involved daily dosages that ranged from 100 to 200 mcg, according to Tufts. The tolerable upper level intake level, or UL, for selenium for adults is 400 mcg, as established by the Institute of Medicine of the National Academy of Sciences. Taking more supplemental selenium than this amount may cause selenosis, or selenium toxicity. This condition is characterized by upset stomach, thinning hair, tiredness, irritability, nail abnormalities, breath that smells like garlic and nerve damage. Selenium toxicity can even be fatal if you take this supplement in high dosages.
Recommended Dietary Allowance
Unless you have health concerns that require use of selenium supplementation, you should be able to get more than enough selenium from your diet. The recommended dietary allowance, or RDA, for adults age 19 and older is 55 mcg daily. Pregnant and breastfeeding women need slightly more selenium: 60 and 70 mcg a day, respectively. Foods rich in selenium include seafood such as crab, shrimp, halibut and salmon. Selenium is also found in organ and muscle meats and foods grown in selenium-rich soil. According to the Linus Pauling Institute, a single ounce of Brazil nuts can give you more than 500 mcg of selenium, which exceeds the RDA for adults.
Cautions
National Institutes of Health online medical encyclopedia Medline Plus indicates that taking supplemental selenium that doesn't exceed the UL is safe for most people, as long as you do so short-term. Although selenium is an antioxidant that some people take to prevent heart disease, cancer and other chronic illnesses, long-term selenium use may increase your risk for diabetes, skin cancer and other types of cancer. The National Center for Complementary and Alternative Medicine states that antioxidants such as selenium, beta-carotene and vitamins C and E may give you the best protective benefits when you get them from the foods you eat rather than from supplements. Selenium supplements can interact with medications such as aspirin and other blood-thinning drugs, statins, barbiturates, oral contraceptives and other dietary supplements such as zinc and niacin. Err on the safe side and talk to your treating physician before you self-treat with selenium supplements or any other dietary supplements.
References
- MayoClinic.com; Selenium Supplement (Oral Route); November 2010
- Linus Pauling Institute; Selenium; J. Higdon, Ph.D.; October 2003
- U.S. Office of Dietary Supplements: Selenium
- Tufts Medical Center; Selenium; February 2011
- National Center for Complementary and Alternative Medicine; Antioxidant Supplements for Health; March 2011
- Medline Plus; Selenium; May 2011
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