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Selenium Status and Mortality Risk

All-cause mortality, cancer mortality, and cardiovascular disease mortality are all three significantly associated with selenium status in the blood. Higher selenium status correlates with lower mortality risk. In particular, the inverse relationship with all-cause mortality was strong among different study populations in different countries and in different study regions. The inverse relationship was strong with different selenium measurement methods, with different study recruitment years, and with different study sizes and study follow-up lengths [Cui 2025].

Grave of Edith Piaf in the Pere Lachaise cemetery
Nearly a billion people in the world live in selenium-poor regions. Low selenium status in humans is strongly associated with an increased mortality risk.

These are the conclusions from a systematic review and meta-analysis of 20 observational studies that enrolled 67,534 study participants. The studies included 17 studies of all-cause mortality, 7 studies of cancer mortality, and 9 studies of cardiovascular disease mortality. The review shows that a concentration increase of one standard deviation in serum or plasma selenium biomarkers was associated with 13% lower all-cause mortality, 15% lower cancer mortality, and 11% lower cardiovascular mortality [Cui 2025]. read more

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Selenium and Skeletal Muscle Energy Generation

Selenium is an essential mineral for humans and animals. Selenium deficiency can occur at low dietary intake levels. Sub-optimal and deficiency levels of selenium are associated with negative health outcomes [Wesolowski 2022; Bomer 2020].

Woman exercising
Not much research has been done on the role of selenium in skeletal muscle mitochondria beyond investigations of selenium’s antioxidant roles. Some evidence indicates that selenium may influence mitochondrial bio-genesis and function in skeletal muscle.

Selenium is best known for its biological role as a component of antioxidant selenoproteins, in particular the glutathione peroxidases and the thioredoxin reductases. These antioxidant enzymes protect against
oxidative stress, reduce the extent of systemic inflammation, and regulate
cell death [Wesolowski 2022].

In addition, selenium as a constituent of some 25 known selenoproteins has a variety of physiological functions beyond the antioxidant capabilities. One of the more interesting roles of selenium is the promotion of mitochondrial bio-genesis in skeletal muscle [Wesolowski 2022]. read more

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Selenium and Selenoprotein P

In humans, Selenoprotein P is the selenium-dependent compound that serves as the primary selenium transport protein in the blood circulation. Selenoprotein P, abbreviated SELENOP, is synthesized in the liver. From the liver, then, it carries selenium out to the peripheral cells and tissues. In this way, it is responsible for ensuring selenium homeostasis throughout the body [Schomburg 2022].

Trace element selenium
Selenoprotein P transports selenium from the liver to the other tissues and organs, with high priority to the brain and the testes. SELENOP helps maintain selenium homeostasis in the body. SELENOP also serves as a useful biomarker of selenium status.

In addition, SELENOP plays a role in the antioxidant defense of the organism. It acts as a scavenger of harmful free radicals. It also supports the activity of the glutathione peroxidases and the thioredoxin reductases. These selenium-dependent enzymes have a major role in the antioxidant protection of the cells. Given its antioxidant effects, SELENOP helps to modulate immune system responses [Schomburg 2022]. read more

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Selenium and Heart Failure and Immune Function

Selenium has beneficial effects on the prevention and treatment of heart failure. Higher serum selenium levels are associated with a lower risk of new-onset heart failure and with a lower risk of mortality. Now, data from a 2024 cohort study suggest that strengthened immune system function may be a mechanism that explains the positive effect of selenium [Al Mubarak 2024].

Depiction of human heart
Good heart health depends in part on adequate intake of selenium. Serum selenium status below 70 mcg/L connotes deficiency status. Selenium status below 100 mcg/L is sub-optimal status. The best estimate is that serum selenium status should be in the range of 125-135 mcg/L.

In the study, Al Mubarak et al analyzed the data from a cohort of 2,328 patients diagnosed with heart failure. Heart failure is the medical term to describe patients with a heart muscle that cannot pump as much blood out to the tissues and organs as it should. The heart is too weak or too stiff to fill up with blood and pump out blood optimally. Heart failure is frequently associated with a build-up of fluid in the lungs – causing shortness of breath – and in the lower extremities. The bottom line is that heart failure can be life-threatening [Mayo Clinic Staff 2025]. read more

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Selenium Health Benefits

Selenium is an essential trace element. For our bodies and our immune systems to function well, we need adequate intakes of selenium. Our bodies cannot produce selenium. We need to get it in our diets [Cleveland Clinic 2023].

Selenium properties
Selenium is a trace element that is essential to human health. It has key physiological roles in antioxidant defense, immune function, protection against heavy metal toxicity, reproductive health, and thyroid hormone metabolism.

Who might need a selenium supplement? The answer depends where one lives. It depends upon how selenium-rich or selenium-poor the soil and the foodstuffs are in the local region. In much of North America, for example, the inhabitants generally do not need a selenium supplement. The reason: the soil and the food grown in the soil in much of North America provide adequate amounts of selenium [Cleveland Clinic 2023].

Conversely, there is a greater likelihood that people living in much of Europe and in some Middle Eastern countries will need a selenium supplement. In a systematic review, Stoffaneller & Morse documented widespread sub-optimal selenium intake and status throughout Europe, the UK, and the Middle East [Stoffaneller & Morse 2015]. read more

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Selenium and Thyroid Function

Data from a 2025 KiSel-10 sub-study analysis suggest that serum CD5L levels may be an additional biomarker for improved thyroid function. Serum CD5L levels may also be a suitable biomarker for adequate selenium status and for reduced mortality risk.

Illustration of thyroid gland
Adequate selenium intake is necessary for good thyroid function. Selenium is a component of the deiodinase enzymes that help convert inactive T4 thyroid hormone to active T3 thyroid hormone. Some selenoproteins act as antioxidants to protect the thyroid against oxidative damage. Selenium may help reduce the risk of autoimmune thyroid disorders.

Combined supplementation of elderly citizens with selenium and Coenzyme Q10 for 48 months significantly increased the level of circulating CD5L. The supplementation was associated with improved health-related quality of life and improved survival odds. Meanwhile, in the study’s placebo group, significantly higher cardiovascular mortality within 10 years was associated with low levels of circulating CD5L. The combined selenium and Coenzyme Q10 supplementation reduced the mortality risk. The active treatment in the KiSel-10 clinical trial was 200 mcg of selenium from selenium-enriched yeast and two times 100 mg of ubiquinone Coenzyme Q10 daily [Alehagen 2025]. read more

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Selenium and Heart Failure

Heart failure is a condition in which the heart no longer performs as well as it should. It affects millions of people in the United States and Europe. Heart failure is characterized by the following symptoms:

• shortness of breath
• build-up of congestion in the lungs
• accumulation of fluid in the lower extremities

What do we know about selenium status and the risk of heart failure?

Prof Urban Alehagen selenium and heart disease researcher
Prof Urban Alehagen’s KiSel-10 studies and sub-analyses have shown that selenium supplementation of elderly citizens low in selenium reduces the risk of heart disease mortality.

Low serum selenium levels are associated with increased risk of heart failure [Al-Mubarak 2021; Bomer 2020].

  • Selenium status below 70 mcg/L is regarded as selenium deficiency status [Al-Mubarak 2021; Bomer 2020].
  • Selenium status below 100 mcg/L is regarded as suboptimal status [Al-Mubarak 2021; Bomer 2020].
  • Both selenium deficiency and suboptimal selenium status are associated with increased risk of cellular dysfunction, oxidative stress, and chronic low-grade inflammation [Al-Mubarak 2021; Bomer 2020].

    • What do we know about selenium supplementation and heart failure?

    • Selenium supplementation of individuals with low selenium status may improve heart function and may reduce the need for hospitalization [Alehagen 2022].
    • Selenium supplementation of individuals with low selenium status may reduce the oxidative stress and systemic inflammation that increase the risk of heart failure [Alehagen 2022].

    Selenium and the Risk of Cardiomyopathy

    Myocardium is the medical term for the heart muscle. Cardiomyopathy is a disease or disorder of the heart muscle, often of unknown cause. Keshan disease is a form of cardiomyopathy that develops as a result of selenium deficiency and exposure to a strain of the coxsackievirus. The disease takes its name from Keshan County in northeastern China Its symptoms were first observed there. Keshan disease can result in heart failure [Zhou 2018]. read more

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    Selenium and Healthy Aging

    Healthy aging. How can we slow down and delay the aging process? Certainly, nutrition is one factor in anti-aging. Specifically, adequate intakes of the micronutrient selenium may prevent disease and may enhance healthy aging. Inadequate intakes of selenium, on the other hand, may result in diminished immune function and may accelerate the aging process [Bjorklund 2022].

    Professor Alehagen lectures about selenium and aging
    Professor Urban Alehagen was the lead researcher on the KiSel-10 study of the effect of combined selenium and CoQ10 supplementation on cardiovascular health in elderly citizen low in both substances.

    To a considerable extent, aging is associated with the oxidative damage caused by harmful free radicals to cells and DNA and proteins. Selenium through the work of antioxidant selenoproteins, e.g., the glutathione peroxidases and the thioredoxin reductases, improves our bodies’ antioxidant defenses against free radical damage [Bjorklund 2022; Avery & Hoffmann 2018]. read more

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    Selenium and Pregnancy

    During pregnancy, women need an increased intake of the trace element selenium. Low selenium intake and status in the pregnant mother will be reflected directly in poor selenium status in newborns [Filipowicz 2022].

    Newborn children can be low in selenium
    There is a strong correlation between the mother’s selenium status during pregnancy and the selenium status of the newborn child.

    Women living in regions with low selenium content in the soil and in the food most likely need a selenium supplement. A study conducted in selenium-poor central Poland has revealed that supplemental selenium in a dosage greater than 55 mcg/day can improve pregnant women’s selenium status [Filipowicz 2022].

    In the Polish study, one-third of the mothers reported self-initiated additional selenium intake. For the most part, these women took a multi-vitamin and mineral supplement. The tablet added, on average, 42 mcg of selenium to their diets daily. Even so, 79% of these women had serum selenium concentrations below 70 mcg/L (selenium deficiency levels). Moreover, 22% had serum selenium concentrations below 45.9 mcg/L (severe selenium deficiency levels) [Filipowicz 2022]. read more

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    Low Selenium Status in Elderly Adults

    Many elderly adults have low serum selenium concentrations. This is especially true in the United Kingdom and much of Europe and the Middle East [Stoffaneller & Morse 2015].  Now, a published report shows that over 80 % of the 85-year-old adults in a study in northeastern England had suboptimal serum selenium and selenoprotein P concentrations. Over 40 % had deficient selenium status, judged by reference values derived from studies of healthy adults in all age categories [Perri 2024].

    Elderly man
    Elderly study participants in England, men especially, were found to have suboptimal (80%) or deficient (40%) serum levels of selenium.

    Suboptimal serum selenium status was defined as 70 mcg/L or lower. Serum selenium deficiency was defined as 45 mcg/L or lower.

    The researchers observed a linear association between serum selenium levels and serum selenoprotein P (SELENOP) levels. SELENOP is the primary transport protein carrying selenium from the blood to the peripheral tissues. The findings in this study indicate that most study participants had suboptimal selenium intakes and status. Their diets were not sufficient to saturate the level of circulating SELENOP [Perri 2024]. read more