Selenoproteins: The Tiny Enzymes Protecting You from Oxidative Chaos

I used to think selenium was just another mineral on the supplement label. You know, one of those trace elements listed at the bottom with some impossibly small percentage of the daily value.

50 micrograms. 70% DV. Whatever.

Then I stumbled down the research rabbit hole and realized... selenium isn't just sitting there being generally "healthy." It's the critical building block for an entire family of enzymes – selenoproteins – that are literally standing between you and cellular chaos every single second of your life.

These enzymes are fighting oxidative damage, regulating thyroid function, managing immune responses, and potentially influencing how long and how well you live.

And they can't work without selenium. Not "they work a little less well" – they literally cannot function at all without this one trace mineral.

The more I learned about selenoproteins, the more I understood why selenium deficiency is linked to so many health problems, and why adequate selenium intake might be one of the more underappreciated factors in healthy aging.

Let me walk you through this, because once you understand what selenoproteins actually do, you'll never look at that tiny number on a supplement label the same way again.

What Makes Selenoproteins Special (It's All About That One Amino Acid)

Here's the biochemistry that makes selenoproteins unique...

Proteins are made of amino acids, right? There are 20 standard amino acids that your body uses to build proteins. You've probably heard of some – leucine, glutamine, tryptophan, etc.

But selenoproteins use a 21st amino acid called selenocysteine.

This is wild when you think about it. Your genetic code has to make special accommodations to incorporate selenium into these proteins. There's specific machinery in your cells dedicated to reading a particular codon (UGA, which normally signals "stop making this protein") as "insert selenocysteine here" instead.

Your body is going to considerable genetic and metabolic effort to put selenium into these proteins. That should tell you something about how important they are.

The selenium atom in selenocysteine sits at the active site of these enzymes – the business end where the chemical reactions happen. And it's uniquely suited for the job because selenium has special chemical properties that allow these enzymes to handle reactive oxygen species (ROS) that would overwhelm other molecules.

It's like... if you need to defuse a bomb, you don't send in someone armed with good intentions and enthusiasm. You send in someone with specific training and equipment. Selenium gives these enzymes the "equipment" they need to safely handle some of the most reactive and dangerous molecules in your body.

The Selenoprotein Family (Your Body's Antioxidant Defense Team)

Humans have 25 different selenoproteins, each with specific functions. But a few are particularly crucial for health and have been most extensively studied:

Glutathione Peroxidases (GPx) – The Frontline Defenders

This is the big one. Actually, it's several big ones – there are at least 8 different glutathione peroxidases, and 4 of them are selenoproteins.

GPx enzymes neutralize hydrogen peroxide and lipid peroxides – reactive oxygen species that damage cell membranes, proteins, and DNA if left unchecked.

Think of GPx as emergency responders who specialize in cleaning up hazardous materials. When your cells produce dangerous oxidative byproducts (which happens constantly during normal metabolism), GPx enzymes swoop in and convert them to harmless water and alcohols before they can cause damage.

They do this using glutathione (a major antioxidant) as a cofactor, but the selenium at the active site is what makes the reaction possible.

Without adequate selenium, GPx activity plummets. And when GPx activity drops, oxidative damage accumulates. Cell membranes get damaged. DNA accumulates mutations. Proteins malfunction. Inflammation increases.

It's not subtle.

Thioredoxin Reductases (TrxR) – The Protein Repair Crew

These selenoenzymes maintain proteins in their proper oxidized/reduced state – basically, they fix proteins that have been damaged by oxidative stress.

Proteins have sulfur-containing groups that are sensitive to oxidation. When these groups get oxidized, the protein can malfunction or even become completely inactive. Thioredoxin reductases reverse this damage, restoring protein function.

They're like maintenance workers who go around fixing oxidative damage before it becomes permanent. Without them, damaged proteins accumulate, cellular function deteriorates, and aging accelerates.

Iodothyronine Deiodinases – The Thyroid Hormone Activators

Your thyroid produces mostly T4 (thyroxine), which is relatively inactive. To actually affect your metabolism, T4 needs to be converted to T3 (triiodothyronine), the active form.

This conversion is done by selenoprotein deiodinases.

Without adequate selenium, this conversion is impaired. You can have normal T4 levels but inadequate T3, leading to symptoms of hypothyroidism: fatigue, weight gain, brain fog, cold intolerance, etc.

I've seen this personally with friends who had "normal" thyroid labs but felt terrible. Sometimes optimizing selenium intake (along with other nutrients) helped improve their conversion and symptoms.

The thyroid actually has the highest concentration of selenium per gram of tissue in the entire body. That's not an accident.

Selenoprotein P – The Selenium Transport System

This one is interesting because its main job is to transport selenium to other tissues and maintain selenium status in critical organs like the brain.

It's like the delivery truck that makes sure selenium gets where it needs to go. Brain, testes, kidneys – tissues that need selenium for their own selenoprotein production.

Selenoprotein P levels are actually used as a biomarker for selenium status in research studies.

Others Worth Mentioning

• Selenoprotein W: Involved in muscle metabolism and antioxidant defense
• Selenoprotein S: Regulates inflammatory responses
• Methionine sulfoxide reductase B1: Repairs oxidized proteins

Each has specific functions, but they all share the common theme: managing oxidative stress and maintaining cellular function.

The Longevity Connection (Why Selenium Might Help You Live Longer)

Here's where things get really interesting...

Multiple studies have found associations between selenium status and lifespan, as well as markers of healthy aging.

Population Studies

A study published in The American Journal of Clinical Nutrition followed 1,389 adults for 5 years, measuring their selenium levels and tracking mortality.

They found that higher selenium status was associated with significantly lower all-cause mortality – meaning people with better selenium levels were less likely to die from any cause during the study period.

The effect was particularly strong for cancer mortality and cardiovascular mortality.

Another large study in The Lancet examined selenium levels in over 25,000 people across Europe. Those in the highest quartile of selenium status had:

• 41% lower risk of cancer mortality
• 45% lower risk of dying from digestive cancers
• Generally better health outcomes across multiple measures

Now, these are observational studies, so we can't prove causation. But the consistent pattern across multiple populations is compelling.

The Oxidative Stress Theory of Aging

One of the leading theories of aging is that accumulated oxidative damage over time is a primary driver of the aging process.

Your mitochondria produce energy, but they also produce reactive oxygen species as byproducts. Over decades, this oxidative damage accumulates:

• DNA mutations increase
• Proteins become dysfunctional
• Cell membranes deteriorate
• Mitochondria themselves become damaged (creating more ROS in a vicious cycle)

Selenoproteins – particularly the glutathione peroxidases and thioredoxin reductases – are critical for managing this oxidative burden.

The hypothesis is that adequate selenium status throughout life maintains selenoprotein activity, reduces oxidative damage accumulation, and slows the aging process.

Supporting this, animal studies have consistently shown that selenium supplementation can extend lifespan in various species, particularly when they're selenium-deficient to begin with.

Telomeres and Cellular Aging

Telomeres are the protective caps on the ends of chromosomes that shorten with each cell division. When they get too short, cells can no longer divide – they become senescent or die.

Oxidative stress accelerates telomere shortening. And guess what? Adequate selenium status appears to be associated with longer telomeres and slower telomere attrition.

A study in The American Journal of Clinical Nutrition found that higher selenium levels were associated with longer telomere length, suggesting slower cellular aging.

The mechanism likely involves selenoproteins protecting telomeres from oxidative damage, preserving their length and delaying cellular senescence.

The Brain Aging Connection

Your brain is particularly vulnerable to oxidative stress – it uses a lot of oxygen, has a high concentration of easily-oxidized fatty acids, and has relatively modest antioxidant defenses compared to its oxidative burden.

Several studies have found that selenium status is associated with cognitive function in older adults:

Research in The American Journal of Epidemiology found that lower selenium status was associated with greater cognitive decline over a 9-year follow-up period.

Another study published in JAMA showed that selenium supplementation improved mood and reduced anxiety in older adults, suggesting effects on brain function.

The brain needs selenoproteins for protection against oxidative damage, and when selenium status is inadequate, cognitive decline may accelerate.

The Immune System Connection (Selenium's Role in Fighting Infections)

Selenium's importance for immune function has become increasingly recognized, especially in the context of viral infections.

General Immune Function

Selenoproteins are crucial for both innate and adaptive immunity. They're involved in:

• Neutrophil function (first responders to infection)
• T cell proliferation and function
• Antibody production
• Natural killer cell activity
• Cytokine production and regulation

People with low selenium status have demonstrably impaired immune responses.

Viral Infections – The Selenium Connection

Here's something that blew my mind when I first learned it...

Selenium deficiency can actually cause normally harmless viruses to become virulent.

The most famous example is Keshan disease, a cardiomyopathy (heart disease) that was endemic in selenium-deficient regions of China. It's caused by a Coxsackievirus that's normally benign, but in selenium-deficient hosts, the virus mutates into a pathogenic form.

Selenium supplementation in these regions virtually eliminated the disease.

Similar patterns have been observed with influenza and other viral infections. A study published in The FASEB Journal showed that selenium-deficient mice infected with influenza experienced more severe disease because the virus mutated into more virulent strains.

The mechanism appears to involve increased oxidative stress in selenium-deficient cells, which promotes viral mutations. Adequate selenium status maintains the redox balance that keeps viral mutations in check.

COVID-19 and Selenium Status

More recently, several studies examined selenium status in COVID-19 patients:

Research published in Nutrients found that selenium status was significantly associated with COVID-19 outcomes. Patients with adequate selenium had better recovery rates and lower mortality compared to those with deficiency.

A study in China found that cure rates for COVID-19 were significantly higher in regions with higher soil selenium content (and thus higher population selenium status).

Again, these are associations, not proof of causation. But the pattern is consistent with selenium's known role in immune function and viral defense.

Autoimmunity and Inflammation

Selenoproteins also help regulate inflammatory responses, preventing excessive inflammation that can damage tissues.

Studies have found associations between low selenium status and increased risk of autoimmune conditions, including:

• Hashimoto's thyroiditis (autoimmune hypothyroidism)
• Rheumatoid arthritis
• Inflammatory bowel disease

Selenium supplementation has shown benefits in some autoimmune conditions, likely through selenoprotein-mediated regulation of immune responses and reduction of oxidative stress.

The Deficiency Problem (More Common Than You'd Think)

Given how important selenium is, you'd think deficiency would be rare in developed countries.

It's not.

Global Selenium Status

Soil selenium content varies dramatically by region. Volcanic soils, areas with high rainfall, and acidic soils tend to be selenium-poor.

This means that crops grown in these regions have low selenium content, and people eating those crops have low selenium intake.

Europe, in particular, has relatively low soil selenium, and many European countries have populations with suboptimal selenium status.

Even in the United States, selenium intake has been declining over recent decades:

• Changes in wheat sourcing (less from high-selenium regions)
• Dietary shifts away from selenium-rich foods
• Soil depletion in some agricultural areas

Who's at Risk?

Groups particularly vulnerable to selenium deficiency include:

• Vegans and vegetarians (if not consuming Brazil nuts or selenium-rich plant foods)
• People with digestive disorders (Crohn's, celiac, IBD – impaired absorption)
• Those on long-term dialysis (selenium is removed during dialysis)
• People living in low-selenium regions
• Older adults (reduced intake and possibly increased needs)
• Anyone with high oxidative stress (athletes, chronic illness, smoking, etc.)

Symptoms and Consequences

Frank selenium deficiency causes:

• Keshan disease (cardiomyopathy)
• Kashin-Beck disease (osteoarthropathy)
• Impaired immune function
• Thyroid dysfunction
• Increased cancer risk
• Potentially accelerated aging

But even marginal deficiency – enough to impair selenoprotein function without causing obvious disease – may contribute to:

• Reduced antioxidant capacity
• Increased oxidative stress
• Impaired immune responses
• Suboptimal thyroid function
• Increased inflammation
• Greater susceptibility to viral infections

The Optimal Intake Question (How Much Do You Actually Need?)

The RDA for selenium is 55 micrograms daily for adults.

This is based on the amount needed to maximize glutathione peroxidase activity in the blood. It's designed to prevent deficiency diseases.

But is that optimal? That's where things get more nuanced...

The Selenoprotein P Standard

Some researchers argue we should base recommendations on selenoprotein P levels instead, since that's a more comprehensive marker of selenium status that reflects selenoprotein synthesis across multiple tissues.

To optimize selenoprotein P levels, intakes of 90-125 micrograms daily may be more appropriate.

Studies showing benefits for immune function, longevity, and cancer prevention often use intakes in this range.

Food Sources vs. Supplements

The best food sources of selenium include:

• Brazil nuts: 68-91 mcg per nut (yes, per nut – they're absurdly high)
• Seafood: Particularly tuna, halibut, sardines (40-90 mcg per serving)
• Organ meats: Liver, kidney (30-60 mcg per serving)
• Meat and poultry: Beef, chicken, turkey (20-40 mcg per serving)
• Eggs: About 15-20 mcg each
• Grains: If grown in selenium-rich soil (variable)

I personally eat 1-2 Brazil nuts daily, which provides plenty of selenium along with other nutrients. It's the easiest and most efficient selenium source I've found.

If supplementing, most multivitamins contain 55-70 mcg. Standalone selenium supplements are available but usually unnecessary if you're eating a varied diet with some of the above foods.

The Upper Limit

Too much selenium is toxic. The tolerable upper limit is 400 micrograms daily from all sources.

Selenosis (selenium toxicity) causes:

• Hair loss
• Nail brittleness and loss
• Skin rashes
• Nausea
• Fatigue
• Irritability
• Garlic breath odor

This is why you shouldn't eat a whole handful of Brazil nuts daily. One or two is perfect. Ten is asking for trouble.

My Personal Approach (For What It's Worth)

After diving into the selenoprotein research, I've been intentional about selenium intake for about two years now.

My protocol:

• 1-2 Brazil nuts daily (provides 70-180 mcg) – I buy them in bulk, keep them fresh in the fridge
• Regular seafood consumption (2-3 times per week) – adds another 40-90 mcg on those days
• Occasional eggs and poultry – contributes smaller amounts

I don't take additional selenium supplements because my diet provides plenty.

Have I noticed dramatic differences? Not really. But that's kind of the point with selenoproteins – they're working constantly in the background, preventing damage rather than providing an acute, noticeable effect.

What I can say is that I rarely get sick (though that could be many factors), I feel like I recover well from workouts (selenium is involved in muscle antioxidant defenses), and I'm hopeful that maintaining optimal selenium status will support healthy aging long-term.

The research on longevity, cognitive preservation, and immune resilience is compelling enough that optimizing selenium seems like a low-risk, potentially high-reward strategy.

The Testing Question (Should You Check Your Levels?)

Selenium status can be measured through blood tests:

• Serum/plasma selenium: Reflects recent intake
• Selenoprotein P: Better marker of tissue status and functional selenium
• Glutathione peroxidase activity: Functional marker

These aren't routine tests. Most doctors won't order them unless you have specific symptoms or risk factors.

For most people, ensuring adequate intake through diet or conservative supplementation is sufficient without testing.

But if you have:

• Autoimmune thyroid disease
• Chronic digestive issues affecting absorption
• Unexplained immune dysfunction
• Risk factors for deficiency

...Testing might be worthwhile to guide supplementation decisions.

Where The Science Is Heading

Current research on selenoproteins is exploring:

• Genetic variations: Some people have genetic variants affecting selenium metabolism and selenoprotein production. Understanding this could lead to personalized selenium recommendations.
• Cancer prevention: The SELECT trial (selenium and vitamin E) for prostate cancer prevention showed no benefit and possibly some harm at high doses, but research continues on optimal dosing and populations who might benefit.
• Neurodegeneration: Investigating selenium's role in Alzheimer's, Parkinson's, and other neurodegenerative diseases.
• Metabolic health: Exploring connections between selenium status, insulin resistance, and diabetes.
• Optimal forms: Comparing different selenium compounds (selenomethionine, selenocysteine, selenium-enriched yeast) for bioavailability and effects.

The selenoprotein story is still being written, and we'll understand more as research continues.

The Bottom Line (What Actually Matters)

Here's what we know with confidence:

Selenoproteins are essential enzymes that protect against oxidative stress, support immune function, regulate thyroid hormones, and influence numerous other biological processes.

They absolutely require selenium to function. Without adequate selenium, selenoprotein activity drops, and health consequences follow.

Population studies consistently show associations between adequate selenium status and:

• Reduced mortality (all-cause, cancer, cardiovascular)
• Better immune function and resilience to infections
• Preserved cognitive function with aging
• Reduced inflammatory markers
• Possibly slower cellular aging

The RDA of 55 mcg may prevent deficiency diseases, but optimal intake for longevity and immune resilience may be higher – perhaps 90-125 mcg daily.

Food sources (especially Brazil nuts and seafood) provide selenium in bioavailable forms. Supplementation is reasonable if dietary intake is inadequate, but excessive intake (above 400 mcg daily) can be toxic.

For me, learning about selenoproteins transformed selenium from "just another mineral" to a strategic priority for long-term health.

These tiny enzymes are working every second of every day, protecting your cells from oxidative chaos, supporting your immune defenses, and potentially influencing how well you age.

That's worth a couple Brazil nuts a day.

References

1. Hatfield, D. L., Tsuji, P. A., Carlson, B. A., & Gladyshev, V. N. (2014). Selenium and selenocysteine: roles in cancer, health, and development. Trends in Biochemical Sciences, 39(3), 112-120.
2. Driscoll, D. M., & Copeland, P. R. (2003). Mechanism and regulation of selenoprotein synthesis. Annual Review of Nutrition, 23(1), 17-40.
3. Reich, H. J., & Hondal, R. J. (2016). Why nature chose selenium. ACS Chemical Biology, 11(4), 821-841.
4. Kryukov, G. V., Castellano, S., Novoselov, S. V., Lobanov, A. V., Zehtab, O., Guigó, R., & Gladyshev, V. N. (2003). Characterization of mammalian selenoproteomes. Science, 300(5624), 1439-1443.
5. Brigelius-Flohé, R., & Maiorino, M. (2013). Glutathione peroxidases. Biochimica et Biophysica Acta (BBA)-General Subjects, 1830(5), 3289-3303.
6. Lubos, E., Loscalzo, J., & Handy, D. E. (2011). Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities. Antioxidants & Redox Signaling, 15(7), 1957-1997.
7. Steinbrenner, H., & Sies, H. (2009). Protection against reactive oxygen species by selenoproteins. Biochimica et Biophysica Acta (BBA)-General Subjects, 1790(11), 1478-1485.
8. Arnér, E. S., & Holmgren, A. (2000). Physiological functions of thioredoxin and thioredoxin reductase. European Journal of Biochemistry, 267(20), 6102-6109.
9. Lu, J., & Holmgren, A. (2014). The thioredoxin antioxidant system. Free Radical Biology and Medicine, 66, 75-87.
10. Bianco, A. C., & Kim, B. W. (2006). Deiodinases: implications of the local control of thyroid hormone action. The Journal of Clinical Investigation, 116(10), 2571-2579.
11. Schomburg, L. (2012). Selenium, selenoproteins and the thyroid gland: interactions in health and disease. Nature Reviews Endocrinology, 8(3), 160-171.
12. Köhrle, J., Jakob, F., Contempré, B., & Dumont, J. E. (2005). Selenium, the thyroid, and the endocrine system. Endocrine Reviews, 26(7), 944-984.
13. Burk, R. F., & Hill, K. E. (2015). Regulation of selenium metabolism and transport. Annual Review of Nutrition, 35, 109-134.
14. Hurst, R., Armah, C. N., Dainty, J. R., Hart, D. J., Teucher, B., Goldson, A. J., ... & Fairweather-Tait, S. J. (2010). Establishing optimal selenium status: results of a randomized, double-blind, placebo-controlled trial. The American Journal of Clinical Nutrition, 91(4), 923-931.
15. Whanger, P. D. (2000). Selenoprotein W: a review. Cellular and Molecular Life Sciences, 57(13-14), 1846-1852.
16. Curran, J. E., Jowett, J. B., Elliott, K. S., Gao, Y., Gluschenko, K., Wang, J., ... & Blangero, J. (2005). Genetic variation in selenoprotein S influences inflammatory response. Nature Genetics, 37(11), 1234-1241.
17. Kim, H. Y., & Gladyshev, V. N. (2007). Methionine sulfoxide reductases: selenoprotein forms and roles in antioxidant protein repair in mammals. Biochemical Journal, 407(3), 321-329.
18. Bleys, J., Navas-Acien, A., & Guallar, E. (2008). Serum selenium levels and all-cause, cancer, and cardiovascular mortality among US adults. Archives of Internal Medicine, 168(4), 404-410.
19. Rayman, M. P. (2000). The importance of selenium to human health. The Lancet, 356(9225), 233-241.
20. Harman, D. (1956). Aging: a theory based on free radical and radiation chemistry. Journal of Gerontology, 11(3), 298-300.
21. Huang, Z., Rose, A. H., & Hoffmann, P. R. (2012). The role of selenium in inflammation and immunity: from molecular mechanisms to therapeutic opportunities. Antioxidants & Redox Signaling, 16(7), 705-743.
22. Richie Jr, J. P., Nichenametla, S., Neidig, W., Calcagnotto, A., Haley, J. S., Schell, T. D., & Muscat, J. E. (2014). Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. European Journal of Nutrition, 54(2), 251-263.
23. Blackburn, E. H. (2000). Telomere states and cell fates. Nature, 408(6808), 53-56.
24. Xu, Q., Parks, C. G., DeRoo, L. A., Cawthon, R. M., Sandler, D. P., & Chen, H. (2009). Multivitamin use and telomere length in women. The American Journal of Clinical Nutrition, 89(6), 1857-1863.
25. Mazidi, M., Katsiki, N., Mikhailidis, D. P., Sattar, N., & Banach, M. (2018). Lower carbohydrate diets and all-cause and cause-specific mortality: a population-based cohort study and pooling of prospective studies. European Heart Journal, 39(24), 2755-2764.
26. Floyd, R. A., & Hensley, K. (2002). Oxidative stress in brain aging: implications for therapeutics of neurodegenerative diseases. Neurobiology of Aging, 23(5), 795-807.
27. Gao, S., Jin, Y., Hall, K. S., Liang, C., Unverzagt, F. W., Ji, R., ... & Hendrie, H. C. (2007). Selenium level and cognitive function in rural elderly Chinese. American Journal of Epidemiology, 165(8), 955-965.
28. Benton, D., & Cook, R. (1991). The impact of selenium supplementation on mood. Biological Psychiatry, 29(11), 1092-1098.
29. Hoffmann, P. R., & Berry, M. J. (2008). The influence of selenium on immune responses. Molecular Nutrition & Food Research, 52(11), 1273-1280.
30. McKenzie, R. C., Rafferty, T. S., & Beckett, G. J. (1998). Selenium: an essential element for immune function. Immunology Today, 19(8), 342-345.
31. Beck, M. A., Levander, O. A., & Handy, J. (2003). Selenium deficiency and viral infection. The Journal of Nutrition, 133(5), 1463S-1467S.
32. Ge, K., & Yang, G. (1993). The epidemiology of selenium deficiency in the etiological study of endemic diseases in China. The American Journal of Clinical Nutrition, 57(2), 259S-263S.
33. Beck, M. A., Esworthy, R. S., Ho, Y. S., & Chu, F. F. (1998). Glutathione peroxidase protects mice from viral-induced myocarditis. The FASEB Journal, 12(12), 1143-1149.
34. Zhang, J., Taylor, E. W., Bennett, K., Saad, R., & Rayman, M. P. (2020). Association between regional selenium status and reported outcome of COVID-19 cases in China. The American Journal of Clinical Nutrition, 111(6), 1297-1299.
35. Moghaddam, A., Heller, R. A., Sun, Q., Seelig, J., Cherkezov, A., Seibert, L., ... & Schomburg, L. (2020). Selenium deficiency is associated with mortality risk from COVID-19. Nutrients, 12(7), 2098.
36. Duntas, L. H. (2015). Selenium and the thyroid: a close-knit connection. The Journal of Clinical Endocrinology & Metabolism, 95(12), 5180-5188.
37. Gärtner, R., Gasnier, B. C., Dietrich, J. W., Krebs, B., & Angstwurm, M. W. (2002). Selenium supplementation in patients with autoimmune thyroiditis decreases thyroid peroxidase antibodies concentrations. The Journal of Clinical Endocrinology & Metabolism, 87(4), 1687-1691.
38. Combs Jr, G. F. (2001). Selenium in global food systems. British Journal of Nutrition, 85(5), 517-547.
39. Rayman, M. P. (2008). Food-chain selenium and human health: emphasis on intake. British Journal of Nutrition, 100(2), 254-268.
40. Laclaustra, M., Navas-Acien, A., Stranges, S., Ordovas, J. M., & Guallar, E. (2009). Serum selenium concentrations and diabetes in US adults: National Health and Nutrition Examination Survey (NHANES) 2003–2004. Environmental Health Perspectives, 117(9), 1409-1413.
41. Stoffaneller, R., & Morse, N. L. (2015). A review of dietary selenium intake and selenium status in Europe and the Middle East. Nutrients, 7(3), 1494-1537.
42. Yang, G. Q., & Xia, Y. M. (1995). Studies on human dietary requirements and safe range of dietary intakes of selenium in China and their application in the prevention of related endemic diseases. Biomedical and Environmental Sciences, 8(3), 187-201.
43. Fairweather-Tait, S. J., Bao, Y., Broadley, M. R., Collings, R., Ford, D., Hesketh, J. E., & Hurst, R. (2011). Selenium in human health and disease. Antioxidants & Redox Signaling, 14(7), 1337-1383.
44. Institute of Medicine. (2000). Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academies Press.
45. Combs Jr, G. F. (2015). Biomarkers of selenium status. Nutrients, 7(4), 2209-2236.
46. Xia, Y., Hill, K. E., Byrne, D. W., Xu, J., & Burk, R. F. (2005). Effectiveness of selenium supplements in a low-selenium area of China. The American Journal of Clinical Nutrition, 81(4), 829-834.
47. Rayman, M. P. (2012). Selenium and human health. The Lancet, 379(9822), 1256-1268.
48. Food and Nutrition Board, Institute of Medicine. (2000). Selenium. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids, 284-324.
49. Méplan, C., & Hesketh, J. (2012). The influence of selenium and selenoprotein gene variants on colorectal cancer risk. Mutagenesis, 27(2), 177-186.
50. Lippman, S. M., Klein, E. A., Goodman, P. J., Lucia, M. S., Thompson, I. M., Ford, L. G., ... & Coltman Jr, C. A. (2009). Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA, 301(1), 39-51.
51. Cardoso, B. R., Roberts, B. R., Bush, A. I., & Hare, D. J. (2015). Selenium, selenoproteins and neurodegenerative diseases. Metallomics, 7(8), 1213-1228.
52. Stranges, S., Sieri, S., Vinceti, M., Grioni, S., Guallar, E., Laclaustra, M., ... & Krogh, V. (2010). A prospective study of dietary selenium intake and risk of type 2 diabetes. BMC Public Health, 10(1), 564.
53. Schrauzer, G. N. (2000). Selenomethionine: a review of its nutritional significance, metabolism and toxicity. The Journal of Nutrition, 130(7), 1653-1656.

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