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Selenium Benefits for Health, Plus Dosage Recommendations

By Jillian Levy, CHHC

April 3, 2022

Original article and page source found here.

Selenium is a vital mineral for the human body that has numerous roles.

What is selenium used for? It increases immunity, takes part in antioxidant activity, defends against free radical damage and inflammation, and plays a key role in maintaining a healthy metabolism.

According to studies, consuming foods with selenium — such as Brazil nuts, eggs, liver, tuna, cod and sunflower seeds — and/or taking a daily selenium supplement can have positive antiviral effects, support fertility and reproduction, and may even reduce the risk of some types of cancer, autoimmune diseases and thyroid disorders.

What Is Selenium?

Selenium is a trace mineral that’s found naturally in the soil and in certain foods. There are even small amounts in the water you drink.

What is selenium good for in the body? Something that makes it valuable is its role in antioxidant activity.

As a component of antioxidant enzymes, particularly glutathione reductase, it supports maintenance of healthy tissues throughout the body.

Because it both increases antioxidant capabilities and the quality of blood flow, it can help enhance resistance against diseases and negative effects of stress. Its ability to fight oxidative stress and inflammation is thought to be due to different types of selenoproteins found in this mineral.

Among healthy people in the U.S., a selenium deficiency is believed to be uncommon. However, people with certain health conditions — such as HIV, Crohn’s disease and other disorders that impair nutrient absorption — are at increased risk of having low selenium levels.

Top 8 Selenium Benefits

What are the health benefits of taking selenium? Here’s more about the roles that this essential mineral has:

1. Acts as an Antioxidant and Defends Against Oxidative Stress

This mineral helps fight the aging process and supports a strong immune system by reducing free radical damage.

It has a synergistic effect with other antioxidants like vitamin E, enabling the body to defend against oxidative stress. Stress, of course, contributes to many conditions, including heart disease, neurological conditions and some cancers.

For example, a 2016 review found that having a higher level of selenium exposure could offer protection against breast, lung, colon, gastric, esophageal and prostate cancers.

As an essential component of glutathione peroxidase, selenium also helps carry out important enzyme processes that protect lipids (fats) in cell membranes. It’s needed to fight oxidative degradation of cells and protect against mutation and DNA damage that can cause disease.

2. May Help Defend Against Cancer

Selenium may be especially helpful if you have a weakened immune system or a history of cancer in your family. Taking high dose selenium supplements has been shown to potentially have anti-cancer effects.

According to studies, it may be effective at reducing the risk of cancer incidence, cancer-caused mortality and severity of some types of cancer — specifically in the liver, prostate, colorectal and lungs.

Because it has the special job of activating selenoproteins, this mineral acts in an enzymic role that helps antioxidants to do their job best. There is evidence that it may also help slow down existing cancer progression and tumor growth.

Studies have shown that a high dose can be effective in protecting DNA, which can reduce the risk for cell mutation and cancer development.

Other studies show that in areas of the world where the soil is lowest in selenium, cancer risk is increased when compared to areas that have higher levels naturally available.

3. Can Help Boost Immunity Against Viruses

Selenium supports immunity because it’s needed for the proper functioning of the immune system — plus it’s a key nutrient in counteracting the development of viruses, including HIV.

In patients who have already contracted HIV, it’s been shown to be useful in slowing down the progression of the disease into AIDS.

4. Improves Blood Flow and May Lower Risk for Heart Disease

Low selenium levels are associated with an increased risk of developing cardiovascular disease, potentially along with suffering from a stroke or heart attack. Supplements, or an increase of selenium-rich foods, may be able to help prevent coronary heart disease by protecting arteries against plaque buildup and damage.

It’s believed that dietary selenium may benefit heart health due to its ability to fight inflammation, increase blood flow, reduce free radical oxidative stress and help with antioxidant activity.

5. Helps Regulate Thyroid Function

Is selenium good for your thyroid? Yes, because this mineral acts as a catalyst for the production of active thyroid hormones.

Research now suggests that there is a link between thyroid metabolism and selenium deficiency. Having too little in your diet can impair how your thyroid, and therefore metabolism, works.

The thyroid gland controls numerous important everyday body functions, including appetite, sleep, temperature, weight, energy and more. A problem with proper thyroid function can result in negative symptoms, such as irritability, muscle weakness, fatigue, weight gain or loss, trouble sleeping, and many other reactions.

Acquiring proper amounts of selenium helps the thyroid and body in many important ways:

  • It acts as a powerful protector of the thyroid.

  • It regulates the production of reactive oxygen within the gland.

  • It protects the thyroid gland from antibodies that can create thyroid disease.

For these reasons, selenium may be able to help those with Hashimoto’s disease, Grave’s disease and pregnant women with anti-TPO antibodies.

Does selenium cause weight gain? It shouldn’t. In fact, because it can help with thyroid function, research suggests it supports a normal metabolism and can aid in weight maintenance.

If you’re deficient, it might lead to a sluggish thyroid, which can sometimes cause weight gain.

One study even found that selenium helps protect against obesity — and that higher intake led to significant increases in lean body and muscle mass, along with significant decreases in “hunger hormones” after three months of use among overweight adults.

6. May Help Increase Cognitive Health Into Older Age

Certain studies have investigated the use of selenium supplements for the treatment of dozens of conditions that range from asthma to arthritis, thyroid disorder and Alzheimer’s. The risk of these conditions increase as we age, but high-antioxidant intake and consumption of essential vitamins and minerals can help defend the body and may contribute to a longer life.

For example, a number of studies suggest that higher intake of selenium (and other antioxidants) offers protection against cognitive decline and conditions such as Alzheimer’s disease. A 2019 meta-analysis uncovered evidence for a significant decrease of selenium status in adults with Alzheimer’s compared to to those without it, supporting the mineral’s antioxidant role and the involvement of oxidative stress in neurological impairment.

7. Helps Reduce Asthma Symptoms

Observational studies have demonstrated that patients with chronic asthma may have lower amounts of selenium in their diets and therefore may be prone to deficiency. According to studies, when people with asthma take selenium supplements, they experience less asthma-related symptoms than those who take placebos.

Experts think that supplementation may be a useful add-on treatment to medication for patients with chronic asthma. However, more research is needed before this becomes a regular practice, as researchers have yet to determine the mineral’s full effect on lung function.

8. Can Help Boost Fertility

Selenium benefits fertility because it is required for proper sperm motility and also increases blood flow. These are two key components involved in conception and beating infertility.

This mineral is incorporated into the sperm’s mitochondria capsule and may affect the behavior and function of the sperm as they move through the vaginal canal.

It appears that both low and high selenium concentrations can have a negative influence on the number of sperm, therefore aiming to meet the recommended dietary intake, but not to far exceed it, is important for fertility.

Some studies also show that meeting the recommended dietary intake may even potentially reduce the risk of miscarriage, but more data is still needed.

Supplements and Dosage

Selenium is a trace mineral, meaning we only need a small amount of selenium from our diets each day. However, the body is able to flush it out of your system somewhat quickly since it plays an actionable role in many important body functions — therefore it’s important to consume it regularly.

It’s particularly important maintain normal selenium levels as you age in order to take advantage of its antioxidant benefits.

Some doctors, such as naturopaths, may recommend selenium supplements to treat:

  • acne

  • asthma

  • tendinitis

  • male infertility problems

  • postmenopausal disorders in women

  • and other conditions

It is important to note that if you already consume the proper amount of selenium from a healthy diet, consuming more may not be beneficial. High doses reaching 400 micrograms can even be harmful.

The recommended daily allowance for selenium depends on your age and is as follows, according to the USDA:

  • Children 1–3: 20 micrograms/day

  • Children 4–8: 30 micrograms/day

  • Children 9–13: 40 micrograms/day

  • Adults and children 14 and up: 55 micrograms/day

  • Pregnant women: 60 micrograms/day