Selenium: Important Facts You Need to Know

What is Selenium?  

It is a mineral that our body needs for good health. This mineral is an important component of some proteins and enzymes.  As an essential mineral, selenium is in the foods you eat.  It is also a trace mineral, which means your body does not require large amounts. 

A well-balanced diet will provide all you need to stay healthy.  There are many foods that are naturally selenium rich.  Supplements are also an option if dietary restrictions make it difficult to consume enough.   

Why is selenium important, and what does it help?

Selenium is a nutrient the human body needs to remain healthy.  It plays a pivotal role in protecting your body from damage caused by free radicals.  The nutrient also helps to fight off infection.  Selenium is good for reproduction, thyroid hormone metabolism function and DNA production.   

How much selenium do you need?

The recommended daily allowance for selenium varies depending on age.  See the chart below for a breakdown of RDA.  The National Institutes of Health set the recommended daily allowances.  Refer to chart below. 

What are the signs of selenium deficiency?

First, always keep in mind that symptoms do show a variety of medical issues.  If you suspect a selenium deficiency, consult with your doctor.  

The soils in most North American regions are selenium rich.  This has led to a minimal risk of selenium deficiency in the region.  Even if you are living in an area with soil that is less rich in selenium, foods are imported from many other regions as well.  There are also selenium fortified foods.  

Who is at risk of selenium deficiency?

Fortunately, there are not vast amounts of the American Culture that are at risk.  

• HIV patients
  • HIV patient’s experience malnourishment because of various factors. Malabsorption, infections of the gut and altered metabolism are a few additional reasons.  

• Kidney failure – dialysis patients 
  • Doctors have discovered that antioxidants, like selenium, are impaired by kidney failure from oxidative stress.  Dietary restrictions during dialysis and kidney failure also lead to reduced selenium levels. 

• Regional risks.
  • People living in an area with soil that have low selenium levels and they only consume foods from that single region.  This situation is very rare in the United States.  There are regions around the world that do experience it.  

What happens if your selenium level is low?

Aside from the decreased thyroid function, compromised immune system and diminished DNA production, a selenium deficiency can lead to an array of serious medical conditions.

• Cancer:
  • More studies are necessary, but there is a widespread belief in the scientific community that decreased levels of selenium affect the risk factors of cancer.  A consumer fact sheet produced by the National Institutes of Health suggests that selenium affects an array of cancers: Bladder, colon, esophagus, lung, rectal, skin or stomach.

• Cardiovascular Disease:
  • One study showed that the patients decreased the risk of heart disease by 24% when they increased selenium consumption by 50%.  
  • A second study concluded that oxidative stress was reduced with the use of selenium supplements.  Decreasing this stress also decreased the risk of heart disease.  

• Thyroid Disease
  • The thyroid gland uses high amounts of selenium.  Low levels of it would then lead to a poorly functioning thyroid gland.  
  • One study concluded that selenium “is a prerequisite not only to prevent thyroid disease but also to maintain overall health.”

What is the form of selenium to take?

Selenium comes in various forms.  It is available in selenomethionine, selenate, and selenocysteine.   The gut absorbs selenomethionine and selenocysteine more easily.  

Selenium Rich Foods

There is a large variety of selenium rich foods to choose from.  When you need more information about the nutritional value of any food, the internet has many sites to choose from.  For this chart we used  https://nutritiondata.self.com.  

Like anything else you eat, you can have too much.  Selenium toxicity is a concern to keep in mind.  This is not something that you will need to worry about with one meal that exceeds the recommended daily amount.  We develop it over a longer time period.  

Can selenium cause hair loss?

A healthy head of hair will lose 50 to 100 hairs per day.  These are quickly replaced with new growth.  On average, a person will grow about six inches of new hair each year.  

An excess amount of this trace element increases risk of hair loss.  New hair growth uses selenium, but if there is an excess the hair will become brittle, break off and even thin.    

Can selenium cause weight gain or weight loss?

Because of the effect that selenium has on the thyroid hormone metabolism function weight is impacted.  If the levels are low, then the thyroid may become underactive.  This leads to weight gain from the slower metabolism.  

More research is necessary, but there are studies that show selenium affecting weight loss.  There is potential that the increased levels will cause the hormone metabolism to be overactive.  

Can selenium be dangerous?

Used properly, selenium is a safe nutrient.  However, taking high doses for an extended time period may lead to complications.  Taking doses that are higher than the RDA may also lead to diabetes.

It is possible to develop selenium toxicity if high doses are taken for a long time.  It is always best to discuss any new medications or supplements with your doctor or other medical professional before starting it.  You may have a medical condition or current medication that will interact with anything new.      

Stop taking selenium supplements and contact your doctor if you suspect toxicity.  Keep in mind that it can take at least six weeks for your body to return to normal levels.  

What are the signs of selenium toxicity?

Although not common, this is a concern for anyone that regularly consumes excessive amounts of selenium.  One common food that can lead to toxicity is Brazil nuts.  Just one nut nearly doubles the amount of recommended daily allowance.  Always eat these in moderation.  

Another cause is overusing a selenium supplement.  This poisoning from long-term high doses mimics the effects of arsenic poisoning.  In the most severe cases, toxicity can lead to heart or kidney failure or respiratory distress.  

Summary

Selenium is a required nutrient for a healthy functioning thyroid.  A balanced diet with adequate selenium is the ideal way to maintain your levels of selenium.  Supplements are safe when taken in the correct amounts. 

Always discuss any new medications or supplements with your doctor before starting.  

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