Why would your family need

Selenium as a supplement?

Why are Selenium important in good nutrition? Because….

Which Food Sources contain Selenium?

What is the Role of Selenium in Good Nutrition?

Who need to consume or not consume Selenium?

How much is usually taken?

Selenium acts as an antioxidant, blocking molecules known as free radicals that damage DNA. It is part of an antioxidant enzyme that protects cells against environmental and dietary toxins.

Helps guard against a range of disorders – from cancer, heart-disease, cataracts and macular degeneration to strokes and even aging – thought to be caused by free-radical damage.

It also fights viral infections, reduces the severity of cold sores and shingles, and helps relieve lupus symptoms.

Although it is toxic in large doses, selenium is an essential micronutrient.

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Which Food Sources contain Selenium?

Plant foods are the major dietary sources of selenium in most countries throughout the world. The content of selenium in food depends on the selenium content of the soil where plants are grown.

Dietary selenium comes from nuts, cereals, meat, fish, and eggs. Brazil nuts are the richest natural dietary source. High levels are found in meats such as kidney, crab and lobster, in that order.

Brazil nuts eggs
Brazil nuts Eggs
Crab lobster
Crab Lobster

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What is the Role of Selenium in Good Nutrition?

Selenium is a trace mineral that is essential to good health but required only in small amounts. Selenium works with vitamin E as an antioxidant and it helps protect cells against damage by free radicals, which are reactive by-products of normal cell activity. Selenium is also necessary for the thyroid gland to function normally.

Dermatology clinics in the U.S. from 1983 through the early 1990s studied the effects of taking a daily supplement containing 200 µg of selenium and found it did not affect recurrence of skin cancer, but significantly reduced the occurrence and death from total cancers. The incidence of prostate cancer, colorectal cancer, and lung cancer was notably lower in the group given selenium supplements.

Free radicals are made naturally by the body’s immune system and help destroy invading organisms, but can also harm healthy tissue leading to arthritis. It is therefore believed that Selenium, as an antioxidant, may help to relieve symptoms of arthritis by controlling levels of free radicals. Several surveys indicate that individuals with rheumatoid arthritis, a chronic disease that causes pain, stiffness, swelling, and loss of function in joints, have reduced selenium levels in their blood.

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Who need to consume or not consume Selenium?

Three specific diseases have been associated with selenium deficiency:

  • Keshan Disease, which results in an enlarged heart and poor heart function, occurs in selenium deficient children.
  • Kashin-Beck Disease, which results in osteoarthropathy
  • Myxedematous Endemic Cretinism, which results in mental retardation

Selenium deficiency is rare, even in New Zealand and Finland, where selenium intake is much lower than in the United States and Canada. In China, where selenium intake is even lower, selenium deficiency occurs in association with Keshan disease, a viral disease that affects mainly children and young women. Keshan disease damages the heart, resulting in cardiomyopathy.

In selenium deficiency, antioxidants are lacking in the heart and muscles. As a result, cardiomyopathy and muscle weakness may occur.

Doctors suspect selenium deficiency on the basis of the person's circumstances and symptoms. Treatment with a selenium supplement may result in a complete recovery.

There is evidence that selenium deficiency may contribute to development of a form of heart disease, hypothyroidism, and a weakened immune system. There is also evidence that selenium deficiency does not usually cause illness by itself. Rather, it can make the body more susceptible to illnesses caused by other nutritional, biochemical or infectious stresses.

Severe gastrointestinal disorders may decrease the absorption of selenium, resulting in selenium depletion or deficiency. Gastrointestinal problems that impair selenium absorption usually affect absorption of other nutrients as well, and require routine monitoring of nutritional status so that appropriate medical and nutritional treatment can be provided.

Can you use too much Selenium?

It was found that taking more than 1 milligram of a nonprescription selenium supplement each day can have harmful effects. Typical symptoms include nausea and vomiting, loss of hair and nails, a skin rash, and nerve damage. The diagnosis is based on symptoms, particularly rapid hair loss. Treatment involves reducing selenium consumption.

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How much is usually taken?

The most recent RDA by (the Food and Nutrition Board (FNB) of the Institute of Medicine) is based on the amount of dietary selenium required to maximize the activity of the antioxidant enzyme glutathione peroxidase in plasma

Recommended Dietary Allowance (RDA) for Selenium (mcg/day)


  • 0-6 months - 15 (AI) for Males and 15 (AI) for Females
  • 7-12 months - 20 (AI) for Males and 20 (AI) for Females


  • 1 - 3 years - 20 (AI) for Males and 20 (AI) for Females
  • 4 - 8 years - 30 (AI) for Males and 30 (AI) for Females
  • 9 - 13 years - 30 (AI) for Males and 30 (AI) for Females


  • 14 - 18 years - 55 (AI) for Males and 55 (AI) for Females


  • 19 years and older - 55 (AI) for Males and 55 (AI) for Females


  • All ages - 60 (AI) for Females


  • All ages - 70 (AI) for Females

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