Skip to content
Selenium and Thyroid Health: Essential Guide

Selenium and Thyroid Health: Essential Guide

Selenium and Thyroid Health: Essential Guide


Nestled at the base of your neck, just beneath the Adam's apple, sits the thyroid gland—a small, butterfly-shaped organ that serves as the mastermind behind the body's metabolic processes. By secreting two essential hormones, thyroxine (T4) and triiodothyronine (T3), the thyroid regulates metabolism and energy production, playing a crucial role in selenium and thyroid health. It is pivotal in guiding the body's overall growth and development, including brain development. Your thyroid produces and releases these hormones and parathyroid hormone, which regulates blood calcium levels and maintains adequate calcium stores in the bloodstream to protect bone health. This makes the thyroid a crucial gland for maintaining overall health and wellness. However, if your thyroid is not functioning correctly, surgery may be required to remove it. This surgery called a thyroidectomy, can be done in two main ways: with an incision on the front of your neck or with an incision in your armpit.

The pituitary gland masterfully orchestrates thyroid function, dispatching thyroid-stimulating hormone (TSH) like a messenger, signaling the thyroid to generate and disseminate its vital hormones. These hormones profoundly impact a myriad of bodily functions—they control the pace of your heartbeat, regulate body temperature, manage weight, and determine how swiftly your body consumes oxygen and energy, also known as the metabolic rate. However, when the thyroid is affected by diseases such as goiter, thyroid nodules, or thyroid cancer, it can disrupt the delicate balance of these hormones and lead to various health issues. One treatment option for these conditions is radioactive iodine, which damages thyroid cells and can lead to the destruction of the thyroid gland. The good news is that there are alternative treatments available and steps you can take to keep your thyroid healthy, such as ensuring adequate iodine intake.

However, this intricate system is not impervious to disruption. Dysfunctions within the thyroid can manifest as a range of disorders, prominently hypothyroidism, and hyperthyroidism. Hypothyroidism, a state of deficient hormone production by the thyroid, manifests through symptoms such as persistent fatigue, weight gain, and an intolerance to cold temperatures. Conversely, hyperthyroidism is marked by an excessive production of thyroid hormones, leading to weight loss, an accelerated heart rate, and an increased sensitivity to heat. Both of these conditions fall under the umbrella of thyroid disease, which can significantly impact overall health and well-being. It is important to note that hypothyroidism occurs when the thyroid gland does not make enough thyroid hormone, also known as underactive thyroid. This condition can lead to other health problems if left untreated, including Hashimoto’s thyroiditis, making it crucial to understand the causes of hypothyroidism and address them accordingly.

Common Thyroid Disorders

Thyroid ailments can be traced back to a multitude of triggers, with each specific cause often aligning with different types of thyroid disorders. To leverage clarity, let's explore some key causes associated with a range of thyroid conditions:


  • Hashimoto's Thyroiditis (Autoimmune thyroiditis): Known as the most prevalent cause of hypothyroidism, this is a condition where the immune system erroneously targets and attacks the thyroid gland. This onslaught leads to inflammation and potential damage to the gland, thereby suppressing its ability to produce essential hormones.
  • Iodine Deficiency: Insufficient intake of iodine—essential for thyroid hormone production—can precipitate hypothyroidism. However, this is less commonly observed in regions where salt is iodized routinely or where diets are naturally iodine-rich.


  • Graves' Disease: This autoimmune disorder prompts the immune system to hyperstimulate the thyroid gland, producing excessive thyroid hormone production.
  • Toxic Nodular Goiter: Abnormal nodules or lumps in the thyroid gland can cause unregulated hormone production, resulting in hyperthyroidism.

Thyroid Nodules

  • Benign or Malignant Tumors: Nodules within the thyroid could be either non-cancerous (benign) or cancerous (malignant). While most thyroid nodules are benign, some can disrupt normal thyroid function or even give rise to cancer.


  • Viral or Bacterial Infections: Specific infections can initiate thyroid gland inflammation, termed thyroiditis. This condition can be either temporary or chronic and inevitably impacts thyroid function.

Congenital Factors

  • Certain thyroid complications can originate from birth, often attributable to inherited genetic factors or developmental anomalies.

Impact of Medications and Treatments

  • Specific medications, such as lithium and amiodarone, can have a profound interference with thyroid function.
  • Exposure to radiation therapy, particularly in the head or neck area, can potentially distress the thyroid gland.

Pregnancy-related Factors

  • Some women may encounter the onset of thyroid conditions during or after pregnancy, a notable example being postpartum thyroiditis.

Heavy Metal Toxicity

  • Specific heavy metals—such as mercury, cadmium, uranium, and even halogens like fluoride, bromide, and chloride—can potentially damage or disrupt the thyroid, impairing its ability to produce adequate hormones or function effectively.

Nutrients Essential for Thyroid Health

The thyroid gland depends on a symphony of nutrients to maintain its critical role in regulating metabolism and hormone production. Let's delve into the essential elements required for the thyroid to function at its best:


  • Iodine is indispensable as a foundational building block of thyroid hormones. The thyroid employs iodine to craft thyroxine (T4) and triiodothyronine (T3). Yet, striking a delicate balance is essential since insufficient and excessive iodine intake can lead to thyroid complications.


  • This mineral is a catalyst for transforming T4 into the active form T3. Beyond its role in hormone conversion, selenium is akin to a shield, defending the thyroid against oxidative harm.


  • Integral to the synthesis and metabolic action of thyroid hormones, zinc assists in the transition from T4 to active T3 and is a pillar in maintaining the structural integrity of the thyroid gland.


  • Iron’s role in thyroid health is multifaceted—it supports the synthesis of thyroid hormones and is critical for optimal gland function. Insufficient iron can ripple into thyroid dysfunction, potentially leading to hypothyroidism.

Vitamin D

  • Though famed for its bone health benefits, vitamin D also governs immune function, which can be particularly relevant in autoimmune thyroid disorders. It stands as an ally in fostering overall thyroid well-being.

Vitamin A

  • In the production circuit of thyroid hormones, vitamin A ensures the thyroid tissue remains healthy, aiding in the gland's normal functioning.

Vitamin B12

  • Essential for numerous physiological processes, vitamin B12 influences the effective functioning of the thyroid and the effective conversion of T4 to T3, marking its importance in thyroid health.

Vitamin E

  • Known for its antioxidant prowess, vitamin E helps combat oxidative stress, a silent adversary of the thyroid gland.

Ensuring an adequate supply of these nutrients through a balanced diet or supplements, where necessary, can contribute to preserving the health and operative balance of the thyroid gland.

Selenium and Its Role in Thyroid Function

In this article, we spotlighted the mineral selenium, which is paramount in thyroid function.

We have previously expounded upon selenium as an essential factor that enables the conversion of the thyroid hormone thyroxine (T4) into its more biologically active twin, triiodothyronine (T3). The latter assumes the lion's share of effects on tissues and organs across the entire body, rendering the role of selenium in this metabolic process invaluable. Yet, selenium's functionality in the thyroid is multifaceted, extending far beyond its pivotal role in hormone conversion. Selenium is crucial for maintaining a healthy thyroid, as research shows it can help prevent an underactive thyroid and associated symptoms like fatigue, weight gain, and depression. With its essential role in thyroid function and its potential benefits in preventing or treating thyroid disease, additional research, including clinical trials, is needed to fully understand the impact of selenium on thyroid health and its possible role in reducing the risk of heart disease.

Facilitation of Enzyme Activity

  • Selenium manifests in the body as a vital component of selenoproteins, including a class of enzymes known as deiodinases. Deiodinases take the helm in converting T4 into T3 by cleaving off an iodine atom. This biochemical conversion underpins the balance of thyroid hormones within the body, an aspect crucial to smooth metabolic functioning.

Defense Against Oxidative Stress

  • As an antioxidant, selenium provides a shield, protecting the thyroid gland from oxidative destruction. Given the thyroid's susceptibility to oxidative stress, selenium's antioxidant capabilities become critical in preserving the integrity and function of thyroid cells.

Support for the Immune System

  • Selenium also plays a directorial role in immune system modulation. Sufficient levels of selenium can help guard against or moderate autoimmune thyroid conditions. Autoimmune mechanisms drive disorders such as Hashimoto's thyroiditis and Graves' disease, in which the body mistakenly targets its cells. Selenium could temper the severity of these conditions by contributing to regulating these immune responses.

Thus, a zenith focus on ensuring optimal selenium levels could support overall thyroid health and well-being.

Signs of Selenium Deficiency

Though selenium is theoretically accessible through various dietary sources—such as Brazil nuts, seafood, and organ meats, considered the wealthiest food sources—there's a growing concern that many people may not get enough of this critical nutrient. This deficiency is often attributed to suboptimal farming and agricultural practices, which impair the selenium content in the soil, subsequently affecting the selenium levels in plants and animals and, ultimately, the amount of selenium we consume in North America. The ramifications of selenium deficiency in North America are becoming increasingly apparent, manifesting in several health problems, highlighting the importance of meeting the recommended dietary allowance for selenium.


  • Selenium is integral in synthesizing and regulating thyroid hormones and is pivotal for energy metabolism. Deficiencies in selenium could contribute to a noticeable decrease in energy levels and pervasive fatigue.

Muscular Weakness and Pain

  • Given selenium's significance in muscle function, insufficient levels may result in muscular weakness and pain, compromising physical performance and overall well-being.

Cognitive Challenges

  • Emerging research hints at a potential association between selenium deficiency and cognitive decline, though definitive conclusions require further, more comprehensive studies.

Deterioration of Hair and Nail Health

  • A scarcity of selenium can precipitate adverse changes in hair and nails, including hair loss, thinning of hair, and the emergence of brittle or discolored nails, reflecting its broader impact on overall health.

Thyroid Dysfunction

  • Selenium's central role in converting thyroxine (T4) into the more active triiodothyronine (T3) is essential in maintaining thyroid health. A deficiency might hinder this conversion, ushering in a cascade of symptoms related to thyroid imbalance, such as unexpected weight gain, intolerance to colds, and alterations in skin and hair texture.

Diminished Immune Responsiveness

  • Selenium's involvement in immune regulation means a deficiency could dampen immune function. This weakening of immune defenses may leave individuals more vulnerable to infections and slower recovery times.

Reproductive Health Concerns

  • Selenium not only bolsters general health but also plays a crucial role in reproductive health for both men and women. In men, a deficiency could impact sperm motility, whereas in women, it might affect fertility.

Addressing selenium deficiency by incorporating selenium-rich foods into the diet or considering supplementation (after consulting with a healthcare professional) can help mitigate these risks, highlighting the importance of this micronutrient in our overall health strategy.


In conclusion, understanding the pivotal role of the thyroid gland in regulating metabolic processes underscores the importance of maintaining its health. Disorders such as hypothyroidism and hyperthyroidism highlight the delicate balance required for thyroid hormone production and the wide range of factors that can disrupt this balance—from autoimmune diseases to nutrient deficiencies and even environmental toxins. Selenium, in particular, emerges as a crucial nutrient for thyroid health, supporting hormone conversion, providing antioxidant defense, and modulating immune function. Despite its availability in various foods, the widespread issue of selenium deficiency due to suboptimal dietary intake necessitates a greater awareness. As advised by health professionals, recognizing the signs of selenium deficiency and ensuring adequate intake through diet or supplementation can contribute significantly to thyroid health and overall well-being.

Consider undergoing a Hair Tissue Mineral Analysis (HTMA) to determine if you're facing a deficiency. This screening is considered one of the most precise ways to assess the body's mineral composition.

Moreover, it's important to note that a lack of selenium in your diet isn't the sole concern. Heavy metals, particularly mercury, can displace selenium or interfere with its absorption in your system. Thankfully, testing for mercury levels is also possible through HTMA.

If you're interested in exploring your selenium status further or considering a direct approach to supplementation, schedule your HTMA with us. Also, discover more on how to enhance your selenium intake with our specialized Upgraded Selenium supplement today.

Barbara Madimenos

Hair Tissue Mineral Analysis Practitioner
Functional Diagnostic Nutrition Practitioner
Integrative Nutrition Coach

Older Post
Newer Post
Close (esc)


Use this popup to embed a mailing list sign up form. Alternatively use it as a simple call to action with a link to a product or a page.

Age verification

By clicking enter you are verifying that you are old enough to consume alcohol.


Shopping Cart