Get to Know Selenium – An Essential Trace Mineral

by Melissa Chichester

Have you ever heard of selenium?

A lot of people don’t think about this mineral, but it is very important. Selenium is an essential trace mineral. This means that the body needs a small amount of it daily. The Recommended Dietary Allowance (RDA) for adult men and women over 19 years old is 55 micrograms per day – that is less than 1 milligram! That might seem insignificant, but selenium plays an important role in health and well-being. 

The history of selenium

World-renowned Swedish chemist Jöns Jacob Berzelius discovered selenium in 1817. Berzelius named it after the Greek word for “moon:” selènè. Widely used in industrial applications, selenium has been an important element for photocopying, plumbing brass, and as a semiconductor in electronic devices. Selenium is most commonly used in glass manufacturing to create red and pink shades. 

It wasn’t until 1957 that selenium’s importance in nutrition became known. German biochemist Klaus Schwarz published a paper comparing the presence of liver necrosis in rats eating two different types of protein diets. Ultimately, Schwarz’s study revealed that the rats deficient in selenium developed liver injuries. This paper led to selenium being recognized as essential for health through a large number of studies that took off after his initial research.

Selenium in the body 

According to the National Institutes of Health Office of Dietary supplements, 28% to 46% of the body’s selenium stores are in skeletal muscles. However, the highest concentration of selenium in one place is in the thyroid, according to the Harvard T.H. Chan School of Public Health. 

Foods that contain selenium 

The best way to obtain selenium is through food. By eating just one Brazil nut per day, you are getting the RDA of selenium. One Brazil nut contains, on average, 96 micrograms of selenium. Other foods that contain selenium include:

  • Seafood (tuna, halibut, shrimp)
  • Enriched grains (macaroni, bread, oatmeal, rice)
  • Meat (ham, beef, beef liver) 
  • Poultry (chicken, turkey)
  • Dairy (yogurt, milk)
  • Vegetables (carrots, lettuce)
  • Legumes (lentils, nuts, and seeds)
  • Fruit (bananas, peaches) 

As you can see, selenium is available in a variety of foods. 

Selenium supplements

Supplements are another way to receive adequate selenium. Here are some of our favorite supplements that contain selenium:

Always consult your personal healthcare practitioner before using any kind of supplement.

Selenium benefits 

Selenium is a critical component of several enzymes and proteins and is involved in several processes in the body. For example, selenium (55 mcg daily) supports the immune system.**

It also assists with the proper use of iodine in thyroid function.** Iodine is an essential trace element that is required by the thyroid.** Selenium also has antioxidant properties.** 

As you can see, although the daily requirements for selenium are small, this mineral is important for health and well-being.