A Better Way To Treat Selenium Deficiency In Thyroid Patients

selenium deficiency

In recent years selenium got more attention as a hypothyroidism and Hashimoto’s treatment option because of its involvement in the thyroid hormone pathway and protective role against autoimmune thyroid disease.

In fact, selenium concentration is higher in the thyroid gland than in any other organ in the body making it an important factor in thyroid hormone production and metabolism.

Many research studies demonstrated benefits of selenium for thyroid health and showed that it can help improve thyroid function in people who were already diagnosed with hypothyroidism and autoimmune Hashimoto’s thyroiditis.

I would like to share

7 Ways How Selenium Can Benefit Your Thyroid

selenium benefits1.Adequate selenium levels can protect against autoimmune thyroid disease and goiter development in adults. There is an inverse relationship between selenium status and thyroid volume, risk of goiter and risk of thyroid tissue damage in people with mild iodine deficiency.

2. Selenium supports efficient thyroid hormone conversion and metabolism. There are 11 selenoproteins and enzymes that are essential for the peripheral conversion of T3. Severe selenium deficiency alone can result in hypothyroid symptoms due to impaired conversion of T4 to its active T3 form.

3. Selenium protects the thyroid gland from damage that can be caused by excessive iodine exposure.

4. Selenium acts as an immune system modulator. Selenium deficiency results in a compromised immune system and increased inflammatory response.

5. There is a connection between selenium and reverse T3 (rT3): low levels of selenium can result in increased rT3 while adequate selenium levels can lower the rT3.

6. Supplementing with selenium can reduce inflammation in Hashimoto’s which also means less damage to the thyroid gland and prevention of thyroid tissue damage.

7. Selenium supplementation with selenomethionine for 6-12 months reduces TPO antibodies and decreases the severity of Hashimoto’s disease in some patients.

Why Hashimoto’s Patients Are Prone To Selenium Deficiency?

Despite all these benefits not everyone who has Hashimoto’s has a selenium deficiency and needs to take selenium supplements. As a matter of fact, selenium deficiency is often a sign of another more serious imbalance in your body that needs to be corrected.

Ignoring it means that most of your symptoms will be just masked and not completely reversed by taking selenium supplements.

Research shows that some people affected by Hashimoto’s are more likely than others to have low selenium levels. They include patients with digestive disorders, specifically IBS, celiac and Crohn’s disease as well as severe intestinal inflammation due to a chronic infection.

Thyroid patients with any of these disorders have 3 things in common:

  1. A poor absorption of nutrients
  2. Substantial intestinal damage
  3. Leaky gut syndrome

As a result people who experience these digestive issues are more likely to have low selenium levels and Hashimoto’s disease induced by selenium deficiency.

As you may already know, leaky gut is often a missing link in thyroid autoimmunity and Hashimoto’s treatment. High intestinal permeability opens the door to all kinds of health issues, conditions and symptoms that may even not respond to medication unless the intestinal damage is completely healed.

Hashimoto’s disease is not an exception and this is one of the reasons why so many hypothyroid patients continue to struggle with multiple symptoms even after their thyroid levels become normal.

The good news is that by healing your digestive system and intestinal damage you can reverse selenium deficiency and eliminate your need for selenium supplementation. In some people this alone can lead to Hashimoto’s remission.

Dangerous Side Effects Of Selenium Supplementation

selenium side effects

While selenium supplementation could be effective for some people with Hashimoto’s and low thyroid function, it can also have dangerous side effects.

Early indicators of excessive selenium consumption are a garlic odor in the breath and a metallic taste in the mouth. Hair and nail loss or brittleness are the most common clinical signs of too high selenium intake.

Other possible side effects include gastrointestinal upset such as nausea and diarrhea, skin rashes, mottled teeth, irritability, fatigue and mild nerve damage.

Selenium induced toxicity can occur when it is taken in doses higher than 900 mcg per day over a long period of time.

Acute selenium toxicity can cause myocardial infarction, kidney failure, cardiac failure, acute respiratory distress syndrome, severe gastrointestinal and neurological symptoms, hair loss, muscle tenderness, tremors, lightheadedness, facial flushing and in rare cases, death.

The National Institutes of Health Office of Dietary Supplements suggests that adults should not take more than 400 mcg of selenium per day from both food and supplement sources.

However, some research studies raised a concern that even selenium intake above the Recommended Dietary Allowance of 55 mcg for adults can put you at risk for type 2 diabetes and high blood pressure.

Supplementing selenium may not always bring positive results when you have an underlying thyroid condition. This is especially true when a patient has selenium and iodine deficiency at the same time. In this case taking selenium supplements alone can actually aggravate hypothyroidism.

It is not a good idea to supplement with selenium when you don’t need it if you are a male. Results of a large clinical trial show that male participants who had normal or high selenium status prior to the study experienced a significant increase in the risk of prostate cancer after taking 200 mcg of selenium supplement per day.

What This Research Findings Mean For You?

1.If you have hypothyroidism and/or Hashimoto’s and your hypothyroid symptoms haven’t completely resolved with an optimal dose of thyroid medication consider get a test for selenium deficiency. This test is especially important for Hashimoto’s patients with IBS, Crohn’s, celiac, infections and intestinal inflammation.

It is also a good idea to check iodine levels to make sure that in case you need to supplement with selenium it won’t make your thyroid condition worse. If there is a deficiency, both must be supplemented with a low dose and you should work with a skilled and knowledgable practitioner.

2. If your test results show selenium deficiency talk to your doctor about a short-term supplementation with selenomethionine. This form of selenium was used in the research studies and was proven to bring positive results in Hashimoto’s patients with selenium deficiency when taken at a therapeutic dose of 200 mcg for 6-12 months. In addition, selenomethionine has the best bioavailability with an absorption rate of 90% among selenium supplements.

Seleno-Methionine for Hashimoto's disease

However, keep in mind that despite lower levels of TPO antibodies and better T4 to T3 conversion after using selenium supplements, research studies didn’t observe any improvements in T4 and TSH levels. This means that positive effects of selenium most likely won’t show up on standard thyroid lab tests.

3. If you take selenium supplements, ensure that you are on a safe dose to avoid an overdose and watch for the side effects mentioned above.

4. Alternatively, look into getting adequate amounts of selenium with your diet. Here is a great Thyroid Cookbook that has 100 thyroid-supportive recipes that will provide you with all nutrients your thyroid need.

Here are the top 6 selenium rich foods for your thyroid:

  1. Meats: lamb, chicken and turkey
  2. Fish: salmon, tuna, halibut and cod
  3. Seafood: oysters, scallops, crab and shrimp
  4. Mushrooms: crimini and shiitake
  5. Brazil nuts (it only takes one or two per day due to their high selenium content)
  6. Eggs

Selenium Foods For Thyroid

5. Remember that supplementation with selenium is not generally recommended for all patients with autoimmune thyroid disease. If you don’t have low selenium levels it means that you don’t need to supplement it. In this case possible side effects can outweigh the benefits.

Some studies show that not all Hashimoto’s patients benefit equally from selenium supplements. This fact can be explained when you look into what actually causes low selenium levels in thyroid patients.

6. A better way of dealing with selenium deficiency is to heal leaky gut and repair intestinal damage because the majority of selenium is absorbed in the small intestine. “Sealing your gut” will improve selenium absorption and as a result naturally restore selenium related imbalances in your thyroid hormone pathway.

In addition, healing leaky gut can help you to get rid of many other nutritional deficiencies and triggers of thyroid autoimmunity that come with hypothyroidism and Hashimoto’s disease. Ultimately, it will also mean a symptom relief and a reduced need or, even better making selenium and many other supplements unnecessary.

The subject of leaky gut became so popular in the last years because more and more practitioners and patients realize that this is the root cause of many health conditions and symptoms including Hashimoto’s.

Sadly, many practitioners offer a very restrictive diet, too expensive healing programs and recommend to replenish deficiencies with more supplements that are just not only unaffordable for most people but also not the best way of addressing this issue.

I would like to introduce you to a leaky gut healing program offered by a Functional medicine practitioner Karen Brimeyer who has a different treatment approach that is very affordable and doesn’t involve going on a very restrictive diet and spending hundreds of dollars on supplements. Furthermore, she uses a special technique that helps to reduce her client’s healing time in half.

Learn about her 4 key concepts you need to understand in order to heal leaky gut and restore your selenium levels naturally by clicking here

P.S. If you truly want to experience hypothyroidism and Hashimoto’s symptoms relief your thyroid treatment shouldn’t be limited to only taking thyroid medication and supplements. Dig deeper. Long-lasting symptom relief is so worth it!

P.P.S. Do you like what you read and would like to learn more? Get my free Hypothyroidism Diet Guide


Selenomethionine treatment in patients with autoimmune thyroiditis: a prospective, quasi-randomised trial. Int J Clin Pract. 2012 Apr;66(4):378-83.

Influence of physiological dietary selenium supplementation on the natural course of autoimmune thyroiditis. Clin Endocrinol (Oxf). 2010 Oct;73(4):535-9.

No immunological benefit of selenium in consecutive patients with autoimmune thyroiditis. Thyroid. 2008 Jan;18(1):7-12.

Effects of 12 months treatment with L-selenomethionine on serum anti-TPO Levels in Patients with Hashimoto’s thyroiditis. Thyroid. 2007 Jul;17(7):609-12.

Serum selenium concentrations and hypertension in the US Population. Circ Cardiovasc Qual Outcomes.2009 Jul;2(4):369-76.

A prospective study of dietary selenium intake and risk of type 2 diabetes. BMC Public Health. 2010 Sep 21;10:564.

Selenium status, thyroid volume, and multiple nodule formation in an area with mild iodine deficiency. Eur J Endocrinol 2011;164:585-90.

Association of selenium with thyroid volume and echostructure in 35- to 60-year-old French adults. Eur J Endocrinol 2003;148(3):309-15.

About Marina Gutner, PhD

Marina Gutner, PhD, researcher, medical writer, thyroid blogger, founder and Admin of Outsmart Disease who writes about life-changing treatments for hypothyroidism, Hashimoto's thyroiditis and autoimmune disease and how to balance hormones in women