© Shutterstock

An essential mineral -

Selenium is an essential mineral. It's used in the body to carry out processes, helping several systems function properly.

© Shutterstock

DNA synthesis -

Selenium plays a critical role in DNA synthesis. It acts as an antioxidant, helping to protect cells from oxidative damage.

© Shutterstock

Healthy hair and nails -

Selenium is needed to support healthy hair and nail growth. While white spots on the nails indicate zinc deficiency, white lines on the nail bed indicate selenium deficiency.

© Shutterstock

Thyroid function -

The thyroid has the highest concentration of selenium in the body per weight of body tissue. It's needed for thyroid hormone metabolism in the body.

© Shutterstock

Poor nutrition -

Poor nutrition can be a cause of selenium deficiency, as it's a trace mineral found only in certain, mostly unprocessed, foods. As soils are impacted by climate change, more minerals are being leached, so this could also have an impact on the amount of selenium available for absorption from our food in the future.

© Shutterstock

Risk factors for deficiency -

People with gastrointestinal issues including Crohn's disease or ulcerative colitis could suffer deficiency even if they're eating the right foods, as their digestion doesn't absorb as easily as for others.

© Shutterstock

Fatigue -

One of the most common signs of selenium deficiency is feeling fatigued or constant tiredness, that you can't seem to shake off.

© Shutterstock

Metabolism -

This is due to the role selenium plays in healthy metabolism, as it helps with converting food into energy. This symptom is also a sign of iron deficiency, so you might need to rule that out, too.

© Shutterstock

Constant illness -

Selenium plays an active role in the immune system, contributing to its normal functioning to make you a lot less susceptible to infection or illness.

© Shutterstock

Constant illness -

If your selenium levels are insufficient, you could find your immune system is constantly battling new viruses or illnesses, as it's weakened.

© Shutterstock

Fertility issues -

Selenium plays a role in spermatogenesis, AKA the maturation of sperm cells. Selenium is also present in the tail of the cells.

© Shutterstock

Fertility issues -

Low selenium can lead to decreased fertility, as selenium protects sperm from damage in the development stages. Tests are ongoing to understand if selenium deficiency also affects female fertility.

© Shutterstock

Muscle wastage -

Thyroid synthesis and metabolism affects the rest of the body in different ways. Difficulty with this process, caused by selenium deficiency, can lead to muscle weakness.

© Shutterstock

Muscles need energy to function -

This is because without gaining enough energy from the food that you eat, your muscles won't be supplied with enough energy to function.

© Shutterstock

Hair loss in clumps -

Selenium helps the thyroid convert T4 hormone to an active type called T3. T3 is responsible for growth and development functions in the body.

© Shutterstock

Hair loss in clumps -

If your selenium is low, this process is disrupted and you could have the symptoms of hypothyroidism. One of these is experiencing hair falling out in clumps.

© Shutterstock

Dandruff and itchy scalp -

The antioxidant effects of selenium help to prevent dandruff. If you're not getting enough, you might suffer from excess flaking and an itchy scalp.

© Shutterstock

Weight gain -

Unexpected weight gain is usually not something we welcome. If you haven't made changes to your diet or lifestyle, you'll want to get to the root cause.

© Shutterstock

Weight gain -

As you rule out causes for the weight gain, selenium deficiency might be considered a potential cause. Again, the optimal functioning of the thyroid affects your metabolism, and if that's slowed it can lead to putting on some extra weight.

© Shutterstock

Shortness of breath -

Selenoproteins, the active form of selenium present organically in the human body, are antioxidant warriors with another special role: to protect your heart.

© Shutterstock

Shortness of breath -

Shortness of breath is associated with cardiac health, and low selenium levels are associated with a higher risk of heart disease.

© Shutterstock

Brain fog -

Selenoproteins aren't just used by the heart. They also directly support normal cognitive functioning.

© Shutterstock

Brain fog -

A lack of available selenium to make these proteins can lead to mental fog and difficulty concentrating, making it hard to complete even routine tasks.

© Shutterstock

Increased risk of cancer -

Research from 2014 observed the relationship between selenium and cancer. It found a 31% lower risk where there was higher selenium exposure, notably stomach, bladder, and prostate cancer.

© Shutterstock

Inconclusive overall -

However, other cancer trials have failed to show a benefit from selenium. Nonetheless, eating a diet of selenium-rich foods is probably the safest way to ensure you're getting enough of the mineral.

© Shutterstock

Selenium-rich diet -

Foods like tofu, eggs, tuna, halibut, tinned sardines, baked beans, and meats including beef steak, beef liver, turkey, and chicken are all high in selenium.

© Shutterstock

Brazil nuts -

But the most selenium-rich food of all is the Brazil nut. Just one ounce of them will give you 700% of the recommended daily amount of the mineral.

© Shutterstock

Supplementation -

You can increase your selenium levels by taking a selenium supplement. Some multivitamins contain selenium as an ingredient, but it's available as a standalone product, too.

© Shutterstock

Supplementation -

However, too much selenium can cause toxicity, so do not take more than 400 mcg. A safe dose of selenium supplement should contain no more than 100 mcg.

© Shutterstock

Testing for selenium deficiency -

Selenium deficiency is tested in the nails and scalp hair. It can also be diagnosed by blood testing. If you think you might be deficient, talk to your doctor.

Sources: (Healthline) (The Healthy) (BetterYou) (Holland & Barrett)

See also: Why you need magnesium now

© Shutterstock