Many of the clients we see in clinic have suboptimal function of the thyroid. The thyroid is a butterfly-shaped gland located in the lower front of the neck and it’s functions include:
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Regulating metabolism
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Heart function
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Digestion
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Muscle control
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Bone maintenance
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Mood regulation
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Brain development
Several nutrients contribute to thyroid health – here I am discussing Selenium and Zinc.
Selenium
Selenium is an essential mineral that must be obtained through the diet. It is required in small amounts but plays a crucial role in important bodily processes, including metabolism and thyroid function. You can find selenium in Brazil nuts, fish, ham, pork, beef, turkey, chicken, eggs, brown rice, mushrooms, oatmeal, spinach, lentils, cashews, bananas, dairy products, and enriched food products.
Selenium acts as a powerful antioxidant, which protects against oxidative damage and infections and helps defend your body from chronic conditions, such as heart disease and cancer. It is important to monitor selenium levels, especially for those with digestive issues such as Celiac disease or Crohn’s disease, who may have difficulty absorbing nutrients. Including foods rich in selenium in your diet can help reduce levels of oxidative stress and inflammation.
Selenium and Thyroid
Selenium is also vital to thyroid health and the proper functioning of your thyroid gland. Thyroid tissue contains a higher amount of selenium than any other organ in the human body. Selenium is a mineral that works together with iodine to activate three different selenium-dependent iodothyronine deiodinases. These deiodinases can then activate or deactivate thyroid hormones. This process is crucial for normal growth, development, and metabolism. Not having enough selenium can cause hypothyroidism, Hashimoto’s, an enlarged thyroid (goiter), thyroid cancer, and Graves’ disease. (1)
A study with 1900 participants found that there is an inverse relationship between serum selenium concentrations and thyroid volume. The study also observed that selenium has a protective effect against goiter and thyroid tissue damage. However, these results were significant only for the women participants. (2)
Other research was conducted on the effects of selenium on Graves’ orbitopathy, a thyroid eye disease that occurs due to an overactive thyroid gland. The study compared the effects of selenium treatment with the effects of pentoxifylline, an anti-inflammatory drug. The group treated with selenium reported an improvement in their quality of life, a reduction in ocular involvement, and a slower progression of Graves’ orbitopathy as compared to the group treated with pentoxifylline (3).
Zinc
Zinc is another trace element that is essential for growth, development, and a healthy immune system. Zinc also has a major impact on the nervous and reproductive systems (4).
Zinc is naturally found in a wide variety of both plant and animal foods including beef, lamb, pork, shellfish, legumes, hemp seeds, pumpkin seeds, squash seeds, sesame seeds, pine nuts, peanuts, cashews, almonds, eggs, whole grains, potatoes, green beans, kale, dark chocolate, and dairy products.
Zinc and the Thyroid
Zinc is important for the proper functioning of the thyroid gland. At the same time, thyroid hormones are needed for the absorption of zinc in the body. Hypothyroidism, a condition where the thyroid gland does not produce enough hormones, can lead to zinc deficiency. This, in turn, worsens the functioning of the thyroid gland, leading to a vicious cycle of lower zinc levels. Even when hypothyroid clients are treated with thyroid replacement hormones, they may still experience hair loss. To improve their condition, zinc supplements may be needed in addition to hormone therapy. (5)
Testing for Thyroid Health
To maintain optimal thyroid health, we recommend assessing not only thyroid hormones but also the key nutrients that influence their production and conversion. Selenium and zinc play a critical role in supporting T4 to T3 conversion and regulating thyroid function at a cellular level.
We can work with you to identify any deficiencies and supplement strategically, ensuring levels are optimised without exceeding safe thresholds. Supporting selenium and zinc appropriately can have a meaningful impact on thyroid physiology and overall metabolic health.
For a more complete picture, we also offer the PCH Comprehensive Blood Panel.
This panel covers the full thyroid assessment I use in clinic:
• TSH
• Free T4
• Free T3 (FT3)
• Thyroid antibodies
Free T3 and thyroid antibodies are not routinely included in standard NHS thyroid screening, yet they are essential for understanding production, conversion and potential autoimmune drivers.
Beyond thyroid markers, the panel also evaluates key metabolic and inflammatory indicators that influence thyroid physiology, including fasting insulin, hs-CRP, full iron studies, liver and kidney function, vitamin D and a complete cholesterol profile.
Thyroid function does not operate in isolation. Testing comprehensively allows us to understand what is truly driving your physiology and tailor support accordingly.
For more information, and to book, go to the PCH Comprehensive Blood Panel, or to speak with a practitioner for advice on which test is right for you, please arrange a new client consultation
Consider supplementing with PCH Meta-Boost which contains Selenium, Zinc, Vitamin B6 and Iodine to support thyroid hormone production and regulation for optimal metabolic function.
References:
https://pubmed.ncbi.nlm.nih.gov/19594417/
https://pubmed.ncbi.nlm.nih.gov/12611611/
https://pubmed.ncbi.nlm.nih.gov/21591944/
