What is selenium?
Selenium helps boost immunity, participates in antioxidant activity that fights free radical damage and inflammation, and plays a crucial role in maintaining a healthy metabolism.
You can see why low selenium intake can be problematic.
According to studies, consuming enough natural selenium has positive antiviral effects. It is essential for successful fertility and reproduction and reduces the risk of cancer, autoimmunity, and thyroid disease.
Selenium deficiency is considered relatively uncommon in healthy populations in the United States. However, people living in certain places and those with existing health conditions — such as HIV, Crohn’s disease, and other conditions that impair nutrient absorption — are at greater risk for low selenium levels.
What is Selenium Deficiency?
Selenium deficiency occurs when the amount of selenium in a person’s body falls below the appropriate level.
Selenium is a trace mineral that occurs naturally in soil and some foods high in selenium, even in small amounts of water. Humans and many other animals require trace minerals for optimal health.
What are the benefits of selenium for the body? That is mainly due to its role as an antioxidant.
Selenium benefits include:
- Protection against oxidative stress, heart disease, and cancer.
- Boosting immunity.
- Regulating thyroid function.
- Preventing cognitive decline and increasing fertility.
What happens when you’re deficient in selenium?
Selenium is required for the synthesis of selenocysteine and for the production of selenoproteins and the enzymes and catalysts needed to activate thyroid hormones and antioxidants such as glutathione peroxidase.
Your metabolism, heart, and brain are all affected due to the many functions of selenoproteins. When intake is low, thyroid hormone production is involved, and the immune system is less able to fight off viruses and infections.
The body may be more susceptible to diseases, including cancer, because selenium is needed to control the production of natural killer cells, T cells, antibodies, and macrophages.
Additionally, when deficient, cells are more susceptible to the harmful effects of oxidative stress and exposure to heavy metals such as lead, cadmium, arsenic, mercury, etc. Because selenium is essential for brain health, selenium deprivation may lead to cognitive decline, potential Alzheimer’s disease, depressed mood, and more hostile behavior.
Symptoms of Selenium Deficiency
What are the main symptoms of selenium deficiency?
The most common symptoms of selenium deficiency include the following:
- reproductive problems
- muscle weakness
- brain fog
- Thyroid insufficiency
- Mood-related problems, including depressed mood, anxiety, and hostility
- hair loss
- brittle nails
- A weakened immune system leads to disease susceptibility
- Confusion and Cognitive Changes
Low selenium status has also been linked to obesity and increased risk of several health problems, including inflammation, infertility, immunocompromised function, cognitive decline, and potential mortality from certain types of cardiovascular disease and cancer.
Selenium deficiency and health Iodine deficiency are also common in people affected by Keshan disease, cardiovascular disease, and Kashin-Beck disease, a chronic bone, joint, and cartilage disorder most common in parts of Asia.
Causes and Risk Factors
According to a report in a 2017 article, “Insufficient Selenium Intake Estimated to Affect Up to 1 Billion People Worldwide,” published in the journal PNAS, the risk of selenium deficiency is also expected to increase under future climate change.
Specific populations are more likely to be deficient in selenium due to factors such as the quality of the soil in which they live, medical history, genetics, and how well they absorb selenium.
The RDA for selenium in adults is 55 μg/day. In comparison, the average daily selenium intake in the United States and some developed countries are believed to be 125 μg/day, exceeding the daily requirement. However, some people consume or absorb less due to diet and gastrointestinal health.
Some factors that can lead to low selenium levels include:
1. Low selenium content in the soil
The amount of selenium in the soil varies by location due to rainfall, evaporation, and pH.
For example, some studies have shown concern that parts of Eastern Europe and Africa have low levels of selenium in their soils and that populations living in these areas may suffer from weakened immunity. A review found that intake and status were “sub-optimal” in European and Middle Eastern countries, especially Eastern European countries.
According to research, populations in the Northwest, Northeast, Southeast, and Midwest of the United States may have the lowest levels of selenium due to the soils in these areas. These populations consumed an average of 60 to 90 micrograms of selenium per day, which is still considered adequate but lower than other populations with soils rich in selenium.
Selenium levels are generally adequate in the Great Plains and the Southwestern United States soils.
2. Low intake of food sources
Selenium levels in foods are deficient and largely depend on soil conditions, so even within the same food, selenium levels can vary widely. That means crops grown in some places have higher concentrations of selenium than others.
Infrequent consumption of selenium-containing foods, such as meat, fish, or poultry, also increases the risk of low selenium levels (meaning vegetarians and vegans may be at increased risk).
Some research has also shown that selenium deficiency is linked to vitamin E deficiency, meaning that getting these two nutrients from a healthy diet can prevent symptoms.
3. Health conditions that affect fitness levels
Kashin-Beck disease is a chronic bone disorder associated with deficiency. Having kidney dialysis and HIV infection also increases the risk of low selenium levels. A digestive condition like Crohn’s disease or colitis can also lower its levels.
Liver cirrhosis is another risk factor because the liver metabolizes selenium.
Of all the essential elements, selenium has the narrowest range between dietary deficiency and toxic levels, according to a study published in Essentials of Medical Geology. The body tightly controls selenium levels, so too much or too little can be problematic.
According to the USDA, the recommended daily allowance for selenium depends on your age, as follows:
- Children 1-3 years old: 20 micrograms/day
- Children 4-8 years old: 30 micrograms/day
- Children aged 9-13: 40 micrograms/day
- Adults and children 14 years and older: 55 mcg/day
- Pregnant women: 60 micrograms/day
- Lactating women: 70 micrograms/day
Suppose your condition puts you at risk for selenium deficiency. In that case, you should have your selenium levels tested to see if you can reap the additional benefits of selenium by taking a supplement. You can have your doctor do a blood or hair test to find out your current selenium levels.
Your doctor will also discuss any symptoms of selenium deficiency you may be experiencing, such as hair loss, fatigue, etc. Also, you will want to have your glutathione peroxidase levels tested, as this is required to maintain normal selenium levels.
Remember, blood tests will only show how much selenium you have recently consumed. The accuracy of hair tests is not very consistent because minerals are stored differently in different organs and systems.
For example, your thyroid stores more selenium than anywhere else in your body because selenium plays an essential role in metabolic processes.
Conventional and Natural Remedies
The good news: Is that experts don’t usually find selenium deficiency in people who aren’t generally malnourished or immunocompromised. It’s believed that as long as you’re getting natural sources of selenium regularly in your diet and are otherwise healthy. Yes, you are less likely to be malnourished.
Here are a few ways to help prevent and treat selenium deficiency:
1. Eat foods high in selenium
What foods are high in selenium? The most crucial selenium foods to include in your diet include Brazil nuts, eggs, liver tuna, cod and other fish, sunflower seeds, type A poultry, certain meats, barley, and mushrooms.
Whole foods are the best sources of selenium, primarily if these foods are handled and prepared with care, as selenium can be destroyed during processing and high-temperature cooking.
Obtaining selenium from food is the safest way to prevent low-level intake, as consuming large amounts of selenium through supplements may cause side effects. Consuming more than 900 micrograms per day can be toxic, but finishing this amount from food alone is highly unlikely.
In the future, we may see more countries fortify soils with additional selenium (like yeast) to help improve food supply levels. Selenium-fortified eggs, meat, and dairy products are available in many countries.
2. Consider taking a selenium supplement
Selenium is found in vitamin supplements, including many multivitamins. Adults should consume up to 55 micrograms of selenium per day, such as selenomethionine or selenite. Comparatively, pregnant women can consume up to 60 micrograms per day, and breastfeeding women can consume up to 70 micrograms per day.
While 55 mcg/day is the standard recommended amount, some experts believe supplementation should aim for 70 to 90 mcg/day for adults.
According to research studies, selenium is found in plant foods in organic forms, such as selenomethionine. That has a very high bioavailability. Inorganic forms, such as selenate and selenite, are also available, which have a high bioavailability.
It is important to note that you are already getting the right amount of selenium from a healthy diet. Consuming more selenium may not be beneficial, and high doses above 400 to 900 micrograms may even be harmful as this can lead to selenium toxicity. Therefore, stay within recommendations by supplementing with very high doses without consulting your doctor.
Excess selenium may cause bad breath, fever, nausea, potential liver complications, and even kidney and heart problems. However, these problems only occur in very high levels of selenium that reach a “toxic” state.
Selenium is a trace mineral occurring naturally in soil, food, and water.
Selenium benefits the body in many ways, such as by fighting oxidative stress, inflammation, heart disease, infertility, asthma, and even cancer.
Deficiencies of this mineral are relatively rare but are more likely to affect people with certain health conditions, those with compromised immunity, those who do not eat foods with selenium, and those who live in certain parts of the world whose soils have low levels of the mineral.
Symptoms of selenium deficiency include hair loss, reproductive problems, muscle weakness, fatigue, brain fog, and thyroid dysfunction.
Include selenium foods in your diet to help boost selenium levels. The best sources include Brazil nuts, eggs, sunflower seeds, liver, fish, turkey, chicken breast, sunflower seeds, and mushrooms.