What is selenium All about this trace element

What is selenium ? All about this trace element

Selenium is a trace element essential to the body. This bioelement intervenes in the body through many metabolic reactions. It is a powerful antioxidant that is able to detoxify the body of heavy metals and preserve the heart. Selenium intake, however, must be highly controlled because of its potential toxicity.

Characteristics of Selenium:

  • Anti-oxidant trace element essential to the body
  • Mostly found in seafood
  • Supports immune and cardiovascular systems
  • Selenium deficiency can lead to serious heart failure or death
  • In excess, selenium is toxic and causes selenosis

Why consume foods rich in selenium?

Selenium: health benefits and roles in the body


Selenium is one of the molecules with antioxidant power. It enters, indeed, in the composition of several enzymes charged to neutralize the free radicals in excess and thus the oxidation in the organism. In addition, selenium participates in the regeneration of vitamins themselves antioxidants (vitamins C and E). As a result, a good intake of selenium makes it possible to fight against oxidative stress and against premature cellular aging.

Detoxifies the body of heavy metals

Selenium is known for its depurative properties. It cleans the body of toxic and foreign molecules including heavy metals such as mercury or lead.

Heart Health

Selenium deficiency can cause severe cardiomyopathies that can lead to death. This trace element intervenes, indeed, in the regulation of the cardiac rhythm and participates in the prevention of the diseases of the heart.

Selenium, Beauty of Hair and Skin

This trace element has a beneficial role on the quality of the integuments (hair, nails) and the skin. Yeasts and supplements based on selenium are also known to promote the brightness of the skin and the strength of the hair.

20 foods rich in selenium

Selenium is found in significant quantities in seafood, organ meats, meat and oilseeds. A balanced diet must cover the needs of the body in this trace element.

Foods Servings (μg)
Dehydrated Brazil nuts1/4 cup (60 mL)681 μg
Pacific Oysters, Raw or Steamed100 g (2 to 4 means)77-154 μg
Canned tuna100 g60-80 μg
Offal of turkey or chicken, braised100 g58-60 μg
Swordfish or plaice, baked or grilled100 g58-61 μg
Atlantic herring, pickled100 g59 μg
Atlantic sardines, canned100 g53 μg
Mixed nuts, including peanuts, roasted1/4 cup (60 mL)51 μg
Canned clams100 g (13 medium)49 μg
Cooked pork chops100 g48 μg
Tuna, halibut, cod, redfish, haddock, salmon, baked or grilled100 g40-47 μg
Dried shiitake mushrooms10 mushrooms (36 g)46 μg
Crab or lobster, boiled or boiled100 g32-45 μg
Salmon, baked or preserved100 g38-43 μg
Raw or cooked shrimps100 g38-40 μg
Lamb, shoulder, braised100 g31 μg
Beef100 g27 μg
Duck100 g22 μg
Regular ham (11% fat), roasted100 g20 μg
Poached egg1 big17 μg

How to use selenium properly?

Use of selenium

Daily Needs

Recommended Dietary Allowance (ANC)
Babies 0-6 months15 μg *
Babies 7-12 months20 μg *
Children 1-18 years old1 μg per kilo
Men 19-50 years old70 μg
Women 19-50 years old70 μg
Men 50 and over80 μg
Women 50 and over80 μg
Pregnant women80 μg
Nursing women80 μg

* Sufficient contributions

Food supplements based on selenium

They are often indicated to remove heavy metal residues in the body, to maintain the heart system or to preserve the beauty of the hair and skin. Selenium supplementation can also help fight oxidative stress and strengthen the immune system. The dosage varies according to the problem and the context. Ask your doctor for advice and do not exceed 150 micrograms per day without medical check-ups.

Use of selenium and zinc rich yeast

Brewer’s yeast, in powder or capsule form, is a concentrate of B vitamins, selenium and zinc. It can be helpful in meeting the needs of the body and keeping skin and hair healthy.

Undesirable effects of selenium

Is selenium dangerous in excess?

At very high doses selenium is responsible for selenosis. This excess of intake results in intense fatigue, hair loss and extreme dryness of the skin. People suffering from selenosis have a characteristic breath (smell of garlic) and suffer from digestive problems (nausea, bloating, etc.). In France, the competent authorities recommend not to consume more than 150 micrograms of selenium per day.

Consequence of selenium deficiency

Selenium deficiency can result in decreased immune defenses, cardiac arrhythmias or anemia. It may, to a lesser extent, induce thyroid disturbances, intense fatigue and generalized weakness. In the most severe cases, and in the absence of supplementation, she may be responsible for Keshan’s disease. It is a heart disease due to selenium deficiency and can lead to death.

Interactions with other nutrients

Excess dietary fiber tends to prevent proper assimilation of selenium. The same goes for phosphorus and heavy metals such as mercury.

On the contrary, zinc and selenium have a synergistic action in the body. A good intake of these two nutrients makes it possible to benefit from an optimal antioxidant effect.

Chemical Properties of Selenium

The selenium symbol is Se, its atomic number is 34. This trace element has an atomic mass of 78.971 u and a density of 4.79 g.cm-3. This is a non-gray metal. Selenium shares many chemical properties with sulfur. Indispensable in small quantities, this bioelement can be very toxic for the body when it is consumed in excess.

Selenium disulfide is a salt composed of sulfur and selenium. Its crude formula is SeS2 and its molar mass is 143.09 g / mol. It is an excellent antimycotic and antifungal used therapeutically to treat fungal infections and certain other skin conditions.

Nutrient History

Selenium is well studied for its many interventions in metabolic reactions. Currently, numerous studies are underway to establish the potential beneficial effects of selenium in the prevention of certain cancers (prostate, digestive, etc.). These studies are particularly delicate because of the high toxicity of selenium at doses easily attainable by a drug supplementation.