Selenium and Kidneys…Spotlighting This Super Supplement

What is selenium?

We’ve spoken about Selenium and Kidneys a few times because as far as supplements for kidney issues go, it’s one of the best. Today we’re going to take a more thorough look at Selenium and specifically Selenium and how it effects the kidneys. Selenium is a trace mineral that occurs naturally and is found in many foods; it is also sold as a dietary supplement. Selenium is essential for humans because it plays a vital role in hormonal function, reproduction, infection prevention, and protection from oxidative damage. Humans usually acquire selenium through diet. Once absorbed in the body, the highest stores are found in muscle. Selenium deficiency is not common because only trace amounts are needed. However, if deficiency is suspected, levels of selenium can be measured in the blood. Here’s everything you should know about selenium and kidneys.


How much selenium is required?

For most adults, one needs 50-80 micrograms per day, whereas children need half that amount.


What are the sources of selenium?

For humans, the major source of selenium comes from foods like nuts, meat, seafood, dairy products, eggs, cereals, and whole grains. The amount of selenium is very low and not enough to meet nutritional requirements. The amount of selenium in plant food is variable and depends on the type of soil and the pH. Overall, the levels of selenium in plant foods do vary depending on the geographical location; hence one should not rely on the consumption of plant foods to derive their daily selenium requirements.


What are the benefits of selenium?

Selenium may be a trace mineral with only minimal daily requirements, but it is vital for the body. Evidence collected over the years shows that it may be playing a significant role in the following disorders:

  • Heart disease: Selenium has been shown to decrease inflammation and prevent the oxidative modification of lipids and platelets from aggregating. For these reasons, experts suggest that selenium supplements may lower the risk of heart disease. 


  • Cancer prevention. Because selenium has the ability to repair DNA and has antioxidant properties, it is believed that it may be useful in preventing some cancers. Laboratory work does reveal that it can prevent the uncontrolled multiplication of rogue cells. Clinical observation has shown that high levels of selenium are associated with low levels of many cancers including prostate, colon, lung, skin, and the bladder. However, more research is needed to confirm the relationship between selenium concentrations and cancer risk. In the meantime, the public should eat a healthy diet, not smoke and exercise regularly.


  • Thyroid disease. The highest concentration of selenium occurs in the thyroid gland, where the mineral plays a role in hormone synthesis. Again, observation studies indicate that there is a relationship between selenium levels and the thyroid gland but whether selenium supplements can prevent thyroid disease is not known.


  • Dementia. It is well established that serum selenium concentrations decline with age. Some reports suggest that low or marginal selenium levels may be associated with age-related decline in brain function, possibly due to a decrease in selenium’s antioxidant activity. 


Are selenium supplements available?

Selenium is also widely sold in combination with multivitamins and a stand-alone supplement. For most people, though, there is no need to take selenium supplements if they eat a healthy diet


Selenium Deficiency

When selenium deficiency occurs, it often results in biochemical dysfunction. For example, it may make the individual more prone to infections. Others may develop infertility and joint pain. Unfortunately, healthcare workers do not usually measure selenium levels in the body. Moreover, selenium deficiency rarely occurs alone; it is usually in combination with deficiencies of vitamins and other minerals.


Who is at risk for selenium deficiency?

Selenium deficiency is rare in North America and in isolation, it rarely causes any major health issues. Individuals most prone to developing selenium deficiency include the following:

  • Individuals living in areas where there is selenium deficiency


  • Individual whose diet consists primarily of vegetables grown in selenium poor soil


  • The highest rates of selenium deficiency are seen in China, where the population is heavily dependent on vegetarian foods that are growing in selenium-deficient soil. In addition, the average intake of selenium is low in several European nations, especially in the population that primarily eats a vegan diet


What is the role of selenium in people with kidney disease?

In individuals with chronic kidney disease, there is continual inflammation and stress, leading to the generation of free radicals that damage the tissues. In addition, advancing age, fluid retention, and hemodialysis also increase the levels of reactive oxygen species, which can damage the kidney. Over the past few years, many studies have shown that the use of antioxidants like selenium can help reduce free radicals in chronic kidney disease. 

Suboptimal values of selenium have been observed in individuals with chronic kidney disease prior to dialysis. Besides, it is well established that selenium levels are significantly lower in individuals with kidney disease undergoing hemodialysis. It is believed that during hemodialysis, all the selenium in the blood is removed. Another cause of low selenium in individuals with kidney disease include a poor diet. Often these individuals have no appetite or have dietary restrictions and consequently, the levels of selenium are low.


Overcoming low selenium levels in kidney disease

  • Regular selenium supplements in individuals with chronic kidney disease have been shown to increase the levels of selenium in blood as well as increase the number of red blood cells.


  • Recently another study from Italy has shown that the use of statin drugs can help prevent loss of selenium in individuals with chronic kidney disease. It is believed that statins also have antioxidant properties that spare reserves of selenium. But statins should not be taken solely to increase levels of selenium; instead, the individual should obtain selenium from the diet.


  • Another study has shown that regular consumption of brazil nuts can also increase levels of selenium in people with chronic kidney disease. Brazil nuts are rich in selenium and contain 5 times the daily recommended intake. 



Today, in order to prevent selenium deficiency in chronic kidney disease, many kidney doctors recommend selenium supplementation for individuals on hemodialysis as the positive correlation between taking selenium and kidneys remaining well-supported is widely known. Supplementation with selenium, by either taking a supplement or consuming brazil nuts has been shown to be effective in increasing selenium status and glutathione peroxidase activity. Additionally, those individuals prescribed statins may be less likely to need selenium supplementation; as these medications are known to spare the body stores resulting in higher selenium status.

However, a word of caution. It is important for individuals with chronic kidney disease not to over-consume selenium supplements as this can result in toxicity. Plus, it is vital that one buy selenium supplements from a reputable seller as fake and counterfeit products are common. For more on Selenium and kidneys, be sure to check out our YouTube video about the subject.