Selenium is a trace element that is incredibly important for health. However, in Sweden, the soil is selenium-deficient, and most Swedes unfortunately do not reach the recommended intake levels.
Selenium – The Moon Mineral
Selenium is an essential element needed for healthy joints and muscles, a strong immune system, and normal reproductive function. It was discovered in 1817 by the Swedish chemist Jacob Berzelius and named after the Greek word for the moon, "selene." This was because selenium resembles another element Berzelius had also discovered, which he named after the Earth, "tellur."
It took a long time to understand the vital role selenium plays in human health. In the late 1950s, researcher Klaus Schwarz noticed that his lab rats developed liver disease when fed a specific type of yeast. When he switched to brewer's yeast, the liver issues disappeared. The missing link turned out to be the trace element selenium, which was only present in brewer's yeast.
When Should You Take Selenium?
Swedish soil is selenium-deficient, so selenium should be a staple supplement for everyone. Fortunately, selenium is included in all our multivitamin-mineral products. Selenium is particularly important if you are trying to conceive or are pregnant, have thyroid issues, a weakened immune system, hair loss, or brittle nails.
Symptoms of Selenium Deficiency
There are six primary symptoms of selenium deficiency:
- Fatigue – Mineral deficiencies, including selenium, can lead to persistent fatigue that sleep cannot remedy.
- Brain fog, impaired memory, and difficulty concentrating.
- Weakened immune system – Selenium deficiency negatively affects immune function.
- Muscle weakness – A lack of selenium impacts the entire muscular system.
- Hair loss – Selenium deficiency often leads to hair loss due to its critical role in thyroid hormone function.
- Infertility – Selenium deficiency is a factor that affects fertility. Ensuring no nutritional deficiencies, including selenium, is crucial when trying to conceive or during pregnancy due to its importance for thyroid function and fertility.
Benefits of Selenium
Selenium is vital for health:
- Selenium helps protect cells from oxidative stress.
- Selenium supports normal immune function.
- Selenium contributes to normal spermatogenesis.
- Selenium supports normal thyroid function.
- Selenium helps maintain normal hair and nails.
Growing Pains May Be Linked to Selenium Deficiency
This discovery led to selenium being classified as an essential nutrient for animals and eventually for humans in 1979. Today, we know selenium is present in all our cells and is critical for several bodily functions, including energy production at the cellular level – especially in muscle cells and the heart, which requires a lot of energy. Studies have shown that selenium combined with coenzyme Q10 improves heart function and enhances quality of life in people with heart problems.
Muscle symptoms such as calf cramps, restless legs, and growing pains may sometimes indicate selenium deficiency. According to a study conducted by Swedish pediatricians, severe growing pain improved significantly in children given selenium supplements. However, it’s important to confirm with a doctor that the symptoms are due to selenium deficiency before taking higher doses, especially in children.
Selenium in Organic and Inorganic Forms
Selenium exists in both inorganic and organic forms. Inorganic selenite and selenate are found in soil and absorbed by plants, which convert them into organic selenocysteine and selenomethionine. The inorganic form conducts electricity and is used in the electronics industry, as well as for making pigments, glass colors, and photoreceptors.
A Powerful Antioxidant
Selenium is a component of selenoproteins, many of which act as powerful antioxidants. They protect against oxidative stress and the cell damage it can cause. Additionally, they work synergistically with other antioxidants, particularly coenzyme Q10 and vitamin E. Selenium enhances vitamin E’s antioxidant effect but has approximately 1,000 times greater antioxidant activity. However, without Q10, the body cannot effectively utilize selenium.
Selenoproteins also help the body eliminate toxins such as arsenic, cadmium, and mercury and ensure the immune system functions properly. They are also essential for normal sperm production in men and proper thyroid function. Without selenium, the thyroid hormone thyroxine cannot convert into its active form, triiodothyronine. Selenium deficiency can therefore cause symptoms similar to iodine deficiency, which is also critical for thyroid health.
Swedish Soil Lacks Selenium
Unfortunately, the distribution of selenium is highly uneven across the globe. In some areas, such as North America, selenium levels are higher, while countries like Sweden, Finland, and several other northern European nations have selenium-deficient soil.
Finland and New Zealand address this issue by adding selenium to fertilizers. However, this requires vast amounts of the mineral, which is already becoming scarce due to its use in electronics and the effects of climate change and modern farming practices. A better solution is to include selenium in animal feed, as is done in Sweden, and to take selenium as a dietary supplement.
Our Intake Is Not Optimal
According to the Nordic Nutrition Recommendations, women need 50 micrograms of selenium per day, while men, pregnant women, and breastfeeding women require 60 micrograms. The Swedish Food Agency reports that adult Swedes consume about 40–50 micrograms of selenium per day. The best dietary sources are beef, poultry, eggs, garlic, lentils, and Brazil nuts. A single Brazil nut can contain up to 95 micrograms of selenium, but its content depends on the selenium levels in the soil where the plants are grown (including animal feed) and processing and cooking methods.
"Most Swedes do not reach the recommended intake, but there is a wide range between optimal intake and deficiency. We do not see deficiency symptoms in the population," says Åsa Brugård Konde, a nutritionist at the Swedish Food Agency, in an interview with GöteborgsPosten.
Dr. Mikael Björnstedt, a selenium researcher, notes that while acute selenium deficiency is rare in Sweden, our intake is not optimal. He himself takes supplements and points out that consuming less than 20 micrograms daily can lead to illness.
Excessive selenium intake is not advisable, as it can lead to toxicity. In the Nordic countries, the upper limit for selenium intake is 300 micrograms per day, compared to 400 micrograms in the USA. Studies have shown that up to 800 micrograms daily do not cause toxicity, but in selenium-rich regions of China, where intake reaches 850 micrograms daily, residents have experienced issues such as brittle nails, diarrhea, skin rashes, "garlic breath," and mental problems like fatigue and irritability.
Increased Lifespan with Optimal Selenium Levels
A nine-year study of older French individuals found that those with optimal selenium levels – neither too high nor too low – at the start of the study were more likely to be alive at its conclusion. Participants with the lowest selenium levels had a 54% higher risk of death during the study period. Similar results were observed in a study of 14,000 Americans, where those with up to 130 ng/ml (1.65 μmol/l) of selenium in their blood lived the longest. Mortality increased again at higher levels.
Another example of selenium's role in longevity comes from a Chinese study of 208 centenarians and 238 individuals aged 90–100. Researchers found that the oldest participants had the highest levels of selenium and other minerals like zinc.
The best way to obtain selenium is through food, but as diets often lack sufficient amounts – especially in strict vegetarian diets without Brazil nuts – taking a supplement containing 50–100 micrograms of selenium daily may be appropriate. Food-based supplements with organic forms of selenium are preferable, as they are almost entirely absorbed by the body, unlike inorganic selenium, which is harder to assimilate.
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