Do Selenium Benefits Include Thyroid Health?

Key Takeaways:

  • Selenium is an essential trace mineral that is highly concentrated in the thyroid gland. 
  • You can get selenium from both dietary sources and supplementation.
  • Selenium may have protective benefits for the thyroid and can even help reverse thyroid disease where there is a selenium deficiency present.*

You’ve probably heard of the benefits of minerals like calcium, magnesium, and potassium, but what about selenium? It’s true that we don’t need as much of this trace mineral as we do those other minerals, but this essential nutrient is critical for maintaining a well-functioning thyroid gland. 

In this article, we’ll review the purpose of the thyroid gland, suboptimal thyroid conditions, how selenium interacts with the thyroid, the benefits of selenium and risks of deficiency, and the ways you can get more selenium if you need it, including selenium supplements. 

What does the thyroid do?

Your thyroid is a small, butterfly shaped gland in your neck that wraps around the front of your throat. But its small size belies its power over your energy levels; the thyroid controls your metabolism by producing T3 and T4 hormones, telling the body’s cells how much energy to use. By influencing the metabolism, it also affects: 

  • Body temperature
  • Pulse rate
  • How quickly your body uses energy from food 
  • Brain development in children
  • Growth in children
  • Nervous system activation [1]. 

What happens if your thyroid isn’t working properly? 

There are two typical situations where your thyroid isn’t functioning well: hypothyroidism, when the thyroid doesn’t produce enough hormones, and hyperthyroidism, when it produces too many hormones. 

If your thyroid is underfunctioning (hypothyroid), you’re likely to experience:

  • Fatigue 
  • Sensitivity to cold
  • Muscle weakness, pain, or stiffness
  • Dry skin and thin hair
  • Constipation
  • Weight gain
  • Hoarseness
  • Irregular menstrual cycle
  • Slow heart rate
  • Depression and anxiety [2].

Conversely, if your thyroid is over functioning (hyperthyroid), you might feel:

  • A rapid/irregular heartbeat
  • Fatigue
  • Increased appetite
  • Tremors
  • Sweating
  • Sensitivity to heat
  • More frequent bowel movements
  • Thin skin and hair
  • Anxiety and irritability [3].

Neither of these lists are exhaustive of all possible symptoms, and some symptoms overlap between the two conditions. It’s best to work with your health provider to accurately test your thyroid hormones and other markers that will indicate an over- or underactive thyroid if you suspect one or the other as the root cause of your symptoms. 

In either condition, the thyroid can possibly become enlarged and produce lumps called nodules. These are not usually serious, but you should see your doctor if you notice any changes to your thyroid tissue. 

What is selenium?

Selenium is one of the essential trace minerals we need for cellular function, also serving as a powerful antioxidant.* In the human body, it is found in highest concentrations in the thyroid gland. It also supports reproduction, DNA synthesis, and immune protection. [4]*

Selenium is also a key component of glutathione, the body’s master antioxidant produced in the liver. As a critical component of detoxification, a lot of things can quickly go wrong when we don’t have adequate glutathione in the body. 

How are the two connected?

Selenium is critical to optimal thyroid function. Selenium—along with copper, calcium, iron, and zinc—allows the thyroid to use another key nutrient, iodine, in thyroid hormone production. Through adequate nutritional intake and supplementation, it can also help prevent thyroid disease* [56]. Think of selenium as one of the essential ingredients in the recipe for good thyroid health. 

Other benefits of selenium

Besides thyroid health, adequate selenium levels are associated with brain health and cognitive function, cardiovascular function, and possibly cancer prevention, due to its role as an antioxidant [7].*

It may also help reduce anxiety in those with Hashimoto’s thyroiditis, an autoimmune condition where the immune system mistakenly sees the thyroid as a threat and produces antibodies against it.* Selenium may also help reduce thyroid antibodies [8].*

Is selenium deficiency common?

Selenium deficiency is quite rare in the United States and Canada, but people living in some areas of Eastern Europe and China may have a higher risk of deficiency due to low selenium levels in the soil. So your selenium status is partially dependent on your geographic location. 

However, selenium inadequacy may be much more common, especially in those who have a preexisting condition such as HIV or any condition that leads to malabsorption of nutrients, such as inflammatory bowel disease. Those who follow a vegan or vegetarian diet are also much more likely to have an inadequate amount of selenium, since some of our main food sources of selenium include meat and seafood [9]. 

Risks of selenium deficiency

Risks associated with selenium deficiency and inadequacy are primarily thyroid-related. Inadequate selenium can prevent T3 and T4 hormones from doing their job, slowing down the metabolism and increasing risk of disease manifestation. Specifically, selenium deficiency can have a significant impact on the following conditions.

Graves’ disease

Graves’ disease occurs as a progression of hyperthyroidism, resulting in eye swelling and abnormalities, possibly including vision loss. Like Hashimoto’s disease, it is an autoimmune condition, but the thyroid antibodies cause the thyroid to overproduce instead of underproduce thyroid hormones. 

Naturally, selenium deficiency can worsen Graves’ disease, being one of the key components to healthy thyroid hormone production. Research has found that selenium supplementation in addition to medication may help patients with Graves’ disease support thyroid health status.* It may also support eye health for those with Graves’ ophthalmopathy [1011].* 

Hashimoto's disease

Similar to Graves’ disease, selenium deficiency can also contribute to Hashimoto’s symptoms, but in Hashimoto’s disease, thyroid antibodies cause the thyroid to be underactive, producing the hypothyroid symptoms listed earlier, such as fatigue, muscle weakness, and constipation. 

Many studies have now shown that supplementing selenium can help support thyroid health.* A 2016 study showed that selenium supplementation helped one third of subclinical thyroid patients achieve optimal thyroid health [12].* Another study concluded that selenium supplementation decreased thyroid antibodies in women and may improve the inflammatory response in those with autoimmune thyroiditis [13].* 

How can you increase your selenium levels?

Primarily, we get selenium from our diet. Foods that are abundant in selenium include: 

  • Meat: beef, pork, chicken, liver, kidney, etc.
  • Seafood: tuna, oysters, sardines, halibut, etc.
  • Dairy
  • Grains
  • Brazil nuts [17]. 

As you can see, most of these foods are high in animal protein, but brazil nuts are a remarkably good plant source of selenium. Still, plant foods can be more difficult for the digestive system to extract and absorb nutrients. Those with vegan or vegetarian diets may not be getting enough selenium and may want to consider supplementation. 

Diet may not be enough

In addition to personal dietary choices, allergies or other digestive issues may hinder absorption of selenium through your diet. Selenium in food may also be limited by the health of the soil in which it is grown or pastured, so both plant and animal foods can be affected. 

In the case where you may not have access to selenium-rich food sources, or you simply need to increase your selenium levels, supplementation may be useful. 

Do selenium supplements actually help the thyroid?

In cases where a person is deficient in selenium or may require additional selenium to help regulate thyroid function, selenium supplements can absolutely be useful.* Selenium supplementation may also help prevent thyroid dysfunction, especially if you are predisposed to thyroid disease* [18]. Many studies have shown that selenium can lower thyroid antibodies in autoimmune thyroiditis and help achieve thyroid health [192021].

We developed BodyBio Liquid Selenium to help those who want to increase their selenium levels, simply by adding a few drops in water and consuming daily or as directed by your healthcare provider. Our liquid supplement is easy to add to any beverage and more absorbable than a capsule or pill, which is especially important for people who are already experiencing complications of illness and possible digestive issues. 

Make sure to work with a healthcare professional that can help you measure and track your selenium levels as you supplement and also evaluate your thyroid function to see if the supplementation is having any effect. 

Can you have too much selenium?

Having too much selenium is rare, but it can occur with over-supplementation. This is why working with a healthcare provider and having your selenium levels tested periodically is important. 

Selenosis Symptoms

Symptoms of having too much selenium (selenosis) include:

  • Bad/garlic breath
  • Metallic taste in the mouth
  • Nausea
  • Diarrhea
  • Brittle hair and nails/hair or nail loss
  • Skin rashes
  • Irritability
  • Nervous system abnormalities [22].

You could accumulate toxic levels of selenium by over supplementing, or even by eating too many Brazil nuts (seriously!). Brazil nuts are so high in selenium that you only need one or two per day to get the recommended amount (again, assuming you are digesting and absorbing it) [23]. 

Overall, it pays to be mindful with selenium supplementation; follow your provider’s instructions and monitor your symptoms closely. 

Selenium can benefit both thyroid and overall health

As an essential trace mineral, selenium has wide-ranging health benefits for the human body, but primarily for thyroid health. Along with other inputs like iodine and iron, selenium plays a key role in synthesizing the thyroid hormones that regulate your metabolism. Its deficiency can lead to a number of debilitating symptoms, including exacerbating or even triggering hypothyroidism, a common thyroid condition. 

Fortunately, there is good research on the benefits of selenium supplementation to benefit thyroid health and even help remedy thyroid disease. Learn more about BodyBio Liquid Selenium here, and click here to read more about why minerals are essential to our health.