Skip to main content

Climate changes cause selenium deficiencies

- that are a threat to public health

Climate changes cause selenium deficienciesClimate changes and soil depletion increase the risk of selenium deficiency, especially in Europe as shown by Swiss scientists. Selenium is an essential nutrient, and existing studies clearly show that low selenium intake increases the risk of cancer, metabolic disorders, impaired immunity, poor sperm quality, and atherosclerosis. Selenium deficiencies are therefore to be taken seriously and should be prevented one way or another. A good way to get enough of the nutrient is by taking a high-quality selenium supplement.

The selenium content in crops depends on the selenium levels in the soil in which they have grown. Scientists estimate that around one billion people worldwide lack selenium, and it appears that the problem is about to become even worse. Scientists from the Swiss Federal Institute of Aquatic Science and Technology base their assumptions on an array of analyses of climate and soil conditions, which tell them that different types of change may reduce soil selenium levels even more in the future.

Selenium leaches from the soil, and the problem is worst in Europe

During the period 1994 to 2016, the scientists analyzed 33,241 top soil samples from all parts of the world to measure selenium concentrations. Using 26 different environmental variables such as soil leaching and altering pH values, the researchers could determine how the natural selenium content in soil would change from now until the end of this century.
Their calculations show that farming methods and climate changes will cause additional selenium loss in 66% of the farmlands, and the problem will especially affect soils of Europe, India, China, South America, the southern part of Africa, and the southwest regions of the United States.

Selenium is removed from the soil in the following ways:

  • Harvesting of crops
  • Grazing
  • Leaching – especially as a result of large amounts of rain and drainage
  • Acid rain - contains sulfur that may convert selenium to volatile gases
  • Approved antifungal sulfur compounds may also supplant selenium

Scientists warn against selenium deficiencies

According to the Swiss scientists, their calculations concerning the reduced selenium levels in soil may serve as an early warning to agriculture and humanitarian organizations. The entire problem with selenium deficiency is already known to the public. The British biochemist, Margaret Rayman, has addressed the topic on numerous occasions and expressed concern over the low selenium intake and the increased prevalence of cancer, infertility, rheumatism, and other diseases.

Adding selenium to fertilizers

European soil is generally rather low in selenium, especially in Finland where blood samples showed extremely low selenium status in the population over 40 years ago. Because there was also a high rate of cardiovascular disease, the Finnish government decided to add selenium to agricultural fertilizers back in the 1980s. As a result of the mandatory selenium enrichment, selenium levels in crops went up quite fast, and the Finns’ selenium status increased as well.
Nonetheless, there are disadvantages with adding selenium to fertilizers. The plants only absorb a certain amount of the selenium, and since selenium is scarce, it is vital to avoid waste. Scientists believe the world’s selenium reserves could run out within the next 40 years or so. Therefore, it may be prudent to consider other strategies that make better use of our limited selenium reserves.

Farm animals get selenium supplements, and humans belong to the same food chain

Since 1975, it has been standard procedure for farmers to give extra selenium to animals to prevent various deficiency diseases like impaired fertility, joint inflammation, and cardiovascular problems. Although we humans belong to the same food chain, many are still unable to get enough of this vital nutrient.

Nutritional supplements – a better and faster solution

An estimated 20% of the Danish population gets less selenium than recommended. The daily reference intake (RI) is 55 micrograms. In other countries such as the United States and Japan, the natural selenium intake from the diet is close to 200 micrograms because the soil contains more selenium.
In countries like Denmark where the soil contains very little selenium, supplements of selenium can compensate for the low intake of this nutrient. Organic selenium yeast that contains a variety of different organic selenium compounds provide the same natural variety as you get by eating a balanced diet with many different selenium sources.

Although we eat a balanced diet, it may be a challenge to get enough selenium

Selenium is primarily found in fish, shellfish, organ meat, eggs, dairy products and Brazil nuts (the best selenium source). Surprisingly, a Danish study has demonstrated that even if you eat fish and shellfish five days a week, you are unable to get enough selenium.

100 micrograms of selenium daily saturates an important selenoprotein

Selenoprotein P (or SelP) is a selenium-containing protein that is used as a marker for selenium status in the blood. Studies show that it requires at least 100 micrograms of selenium every day to saturate this important selenoprotein.

Why is selenium essential?

In order to understand selenium’s importance in human health, we need to look at things from a cellular level. Selenium is a part of more than 25 different selenoproteins (selenium-containing enzymes). Some are important for our energy metabolism, while other help break down waste compounds, protect cells against oxidative damage, and support the immune system. Selenoproteins are involved in a large number of vital processes that keep our cells and tissues healthy and well functioning.
It is because of selenium’s omnipotent role in human health that we need to take the scientists seriously in their warnings about future selenium deficiencies.


Jones GD et al. Selenium deficiency risk predicted to increase under future climate change. Proceedings of the National Academy of Sciences 2017

Editorial team. Selenium deficiency promoted by climate change. ETHzüric 2017

Margaret Rayman: Dietary selenium: time to act. British Medical Journal. 1997.
Lutz Shomburg. Dietary Selenium and Human Health. Nutrients 2017

  • Created on .