Home » Plankton Nutrients » Minerals » Symptoms Selenium Deficiency?


Selenium (also known as Seleen) is a trace element that functions as an antioxidant in the human body. Selenium helps to reduce the harmful aspects of heavy metals that sometimes end up in our food. It’s essential for the functioning of multiple processes in our bodies, like cognition, a healthy immune system, and fertility. Selenium contributes to the hormonal metabolism of the thyroid and the DNA-synthesis. It also helps to protect us from infections and oxidative damage according to the United States Office of Dietary Supplements.

Selenium is a important trace element to the human body. Since our body is unable to create this trace element itself, we need to get selenium from our foods. Selenium naturally appears in cereals, dairy products, brown rice, mushrooms, bananas, eggs, Brazilnuts, spinach, fish and plankton.

In the U.S., it rarely happens that someone suffers from a selenium deficiency. However, according to a study from 2017, about one billion people worldwide suffer from a shortage of selenium (1).

The same research predicted that the effects of the current climate change will decrease the selenium concentrations in our soil in different places around the world, including southwest America.

There are certain groups of people that have a higher risk of creating a selenium deficiency. Those people may benefit from using selenium supplements next to their daily meals. It is, however, important to note that if you suspect you have a shortage of selenium, you should always consult a doctor before taking any supplements.

People with a higher chance of having a shortage of selenium are:

- People with AIDS or HIV,
- People with dialyzes or kidney dialyzes,
- People with a chronic bowel disease, like Crohn’s disease,
- People that consume foods from selenium-deficient soils.

A shortage of selenium can be recognized by the following symptoms. If you recognize one or more, please consult your physician. 


Adding sufficient amounts of selenium to your diet can help to pass the winter and flu-season without any issues. According to laboratory research at the University of North Carolina, viruses can inflict more damage when they enter a body with a low level of selenium. (2)(3).

It’s only natural that people that consume too little nutrients get sick more easily. However, the research shows that even a small shortage of one specific nutrient can already allow the virus to evolve into something even more dangerous. After this evolution, it can also affect healthy people. Previous studies show that the same dangers apply to people with vitamin E deficiency (4).

In short: when you have too little selenium in your body, you are more susceptible to viral illnesses. This effect, however, strengthens when you also have a vitamin E deficiency.


The cleaning effect of selenium may help reduce the risk of cognitive or mental decline when people age. The results from various studies, however, vary, and selenium supplements are therefore not yet prescribed for people at risk for Alzheimer's (5). However, it could be that selenium possesses preventative effects that are currently still under investigation (6).

In short: antioxidants are essential for our brain. A deficiency of selenium causes a reduction in antioxidants in the body, including the brain. This can have adverse effects on the brain.


If you are concerned about your fertility, you are certainly not the only one. Fertility complaints among men are widespread. A 2017 study indicates that the male's sperm count has been reduced by 50% in the last 40 years (7).

Selenium is essential for the functioning of the sperm. Selenium not only contributes to the physical development of sperm but also to the motility, which means that it helps to allow the sperm cells to swim. These properties are crucial for regular fertilization. Selenium also protects sperm against free radicals within the body, because like all other cells, sperm cells are susceptible to oxidative damage.

A 2011 study looked at the effects of selenium in combination with vitamin E in 690 different men for 100 days. The results showed that the mobility, size, and shape of the sperm cells were improved by 52%. There was also an increase in the number of successful pregnancies by as much as 10.8% (8).

A recent study found that men from an infertile couple had reduced antioxidant values and selenium counts in their sperm. Although it is rare today, some people have low amounts of selenium in their bodies, such as vegetarians and vegans. The current recommended daily intake is 75 mg per day for men and 60 mg per day for women (9).

In short: selenium is essential for developing well-swimming and healthy sperm cells and helps protect them against oxidative damage. Selenium deficiency weakens sperm cells, thereby reducing male fertility.


A Dutch study from 2019 shows that a selenium deficiency increases the risk of heart failure because the body is less able to defend itself against diseases. Patients with heart failure due to a selenium deficiency also are at risk of intolerance for exercise, an increased mortality rate of up to 50%, and a reduced quality of life, says Nils Bömer of the UMCG (10). A quarter of heart failure patients were found to have a selenium deficiency, according to the European Cohort with a total of 2500 patients from eleven different countries.

During his research, Bömer investigated whether there was a connection between these two properties. To do that, he cultivated myocardial cells (heart muscle cells) and tested their responses to a selenium deficiency.

The research showed that a too low level of selenium not only increases the risk of a heart attack, but it also makes the effects of such an attack even worse. In general, different antioxidants get activated when someone has a heart attack. A deficiency of selenium weakens this process and the myocardial cells do not produce enough energy to function. As a result, the mortality rate of the patients increases and their exercise tolerance decreases.

However, it is challenging to overdose on selenium because it is an essential micronutrient. It is an important building block of selenoproteins (proteins) that help regulate inflammation, cancer, and thyroid hormones (11).

In short: : a recent study has shown that a lack of selenium in the body is associated with an increased risk of heart failure. In addition to that, a deficiency of selenium can also cause a more severe reaction to a heart attack.


Selenium is needed for the synthesis and metabolism of the thyroid hormones. During a 1991 study, researchers Benton and Cook conducted a randomized controlled crossover-trial with 100mcg of selenium and a placebo in 50 people for 5 weeks. This was followed by a 6-month washout, after which they continued with the crossover-trial. Selenium was found to be linked to increased mentions in a self-reported state of mind.

This same study tells us that when it comes to a deficiency of selenium, the brain is the last place where selenium levels fall, indicating that selenium is vital for the brain (12)(13).

In short: selenium can have a positive effect on the state of mind of the human being. Also, it is an essential substance for the brain, which means that these levels will decrease last in the event of a deficiency.


Selenium performs an essential task in our body. The selenoproteins regulate the reacting oxygen species (ROS) and the oxidative damage within the cells. This shows that selenium has a strong influence on inflammation and the immune system (14).

However, there is not enough evidence that selenium has an effect on multiple functions of the immune system. For example, the supplementation of selenium has little or no impact on people with asthma, while selenium does counteract oxidative damage within cells (15). A 2008 study shows that selenium from animal milk products would have a better effect on the immune system than regular selenium supplements (16).

The same research indicates that within mice, a deficiency of selenium is often associated with an increased risk of viral diseases such as Influenza, HIV, and the Coxsackie virus. However, there appeared to be no difference in antibodies against these diseases. The mice with low selenium content had more oxidative damage and therefore experienced more physical stress that made them more susceptible to viral infections. It turned out that mice with sufficient selenium had a more significant TH-1 response. These are helping T cells that attack foreign cells (17).

In short: selenium has several positive effects on the immune system. This protects against oxidative damage and inhibits inflammation. Besides, a deficiency of selenium makes you more susceptible to viral diseases.


When we think of our muscles, we often think of our skeletal muscles, while we tend to forget about our heart muscles. A 2003 study by Chariot suggests that various skeletal muscle disorders that cause muscle weakness, pain, and fatigue can be linked to low selenium levels.

However, a deficiency of selenium is also associated with the heart muscles. This disorder is also called Kashan disorder. Muscle weaknesses can also occur in patients who are fed via IV tubing. This is because liquid food generally contains little selenium (18).

In short: selenium is essential for the muscles. Selenium deficiency, therefore, can cause muscle weakness in both the skeletal muscles and the heart muscles.


Although fatigue is a common symptom for multiple disorders, there is often a mention of the impact of a selenium deficiency on human energy levels. This may have to do with the fact that selenium plays a significant role in the functioning of the thyroid gland. When a selenium deficiency develops, the hormones in this muscle can no longer function properly, weakening the metabolism and reducing the amount of oxygen pumped through the blood. Eventually, that causes you to feel tired (19).

In short: selenium has been associated with fatigue in several instances. This association may have to do with the influence that selenium has on the thyroid gland.