Thyroid imbalance is one of the most common imbalances seen in my practice. Thyroid labs can be confusing. In this article, we dive deep into thyroid biology so you can develop a deeper understanding of thyroid biology, what to test and important nutritional factors for a healthy thyroid.

What is your thyroid?

Your thyroid is a butterfly shaped gland which sits in front of your neck, and releases thyroid hormone. Thyroid hormone impacts almost every cell in your body. It’s function is far and wide:

  • Regulates your metabolism (how you burn your food and produce energy)
  • Impacts your digestive function (fast or slow)
  • Influences neurological and brain function (mood, concentration, focus)
  • Impacts your cardiovascular system
  • Regulates your bone and tissue growth
  • and many many more things!


Your thyroid hormone is a very important hormone in the body. And it is very commonly out of balance.


Signs of thyroid imbalance.


How your thyroid hormone is regulated.

Your thyroid hormone is a tightly regulated pathway. It depends on communication between your brain and thyroid gland. It all starts in the brain:

  1. Hypothalamus (brain):  Produces TRH (“thyrotrophin releasing hormone”) and sends it to your pituitary gland.
  2. Pituitary gland (brain): Activated by TRH, and releases TSH (“thyroid stimulating hormone”). TSH is sent to your thyroid gland.
  3. Thyroid gland: TSH binds to receptors on the thyroid gland and stimulates the production of T4 (thyroxine) and T3 (triiodothyronine). T4 and T3 are then released into the blood.
  4. Cells: T4 and T3 bind to receptors on your cells and can now preform its designated function.
    • T4 is converted into T3 inside the cell.
    • T3 is the active form of thyroid hormone.
  5. Regulation: When sufficient amounts of thyroid hormone are produced, there is more T4 and T3 present in the blood.
    • This is detected by the brain (your hypothalamus and pituitary), and causes them to release less TRH and TSH.
    • A reduction in TRH and TSH results in less stimulation of your thyroid gland and therefore a reduction in thyroid hormone production. 
    • As blood levels of thyroid hormone decreases, your brain can detect this and fine tune how much TRH and TSH are released, thus regulating the thyroid levels.

thyriod biology


Labs to test thyroid function.

Standard thyroid labs typically only look at TSH. Now that you have an understanding of thyroid biology, you can see that simply testing TSH misses a large portion of the picture. TSH tells us how your brain is communicating to your thyroid gland. However, it does NOT tell us how your thyroid is RESPONDING to that signal. It also does NOT tell us if there are possible inflammatory issues also impacting your thyroid balance.

Thyroid panel

A thyroid panel looks at TSH, free T4, free T3 and anti-TPO. This provides a comprehensive look at how your brain, thyroid gland and cells are working together. We are able to see if your thyroid gland is responding to the brain signal (TSH), and if your cells are doing a good job at converting T4 into the active form, T3. It also looks at one autoimmune marker (anti-TPO), implicated in two common autoimmune thyroid conditions, Hashimoto’s thyroiditis and Graves disease. 

Finding your “normal” thyroid level

Reference range to determine “normal vs abnormal” thyroid levels are widely debated and VERY person-dependant. Two people can have the same levels of thyroid hormone (based on their lab results), but can have widely different symptoms. This is why as a naturopathic doctor, I never treat the labs, I treat the person. 

health continuum




Nutrients that support your thyroid gland.

There are several nutrients that are required for the production of thyroid hormone. These include:

  • Selenium: This mineral is required for support thyroid conversion (T4 to T3) and reducing oxidative stress within the thyroid gland. Sources: brazil nuts – all it takes is 2 per day!
  • Iodine: This mineral is the backbone of thyroid hormone; it’s needed to produce T4 and T3. Deficiency in North America is less common but on the rise. Overconsumption of iodine may cause either too low or too high thyroid hormone production, so supplementing must be done under the supervision of your doctor. Best sources are foods from the sea: kelp, seaweed, nori, wakame, fish and shrimp.
  • Iron: Adequate levels required for thyroid hormone production and conversion. Iron levels can be challenging to bring up (if you’re deficient) and may need to be supplemented. Best sources are from animal protein.
  • Zinc: Another important mineral for thyroid hormone production, and commonly deficient! Sources: pumpkin seeds, shellfish, animal protein, lentils.
  • Vitamin D: Vitamin D deficiency is seen in those with hypothyroidism. Deficiency is especially common here on the pacific northwest. Vitamin D levels may be something you want to get tested, when treating thyroid disorders. Sources: sun exposure or supplementation.

Some of these deficiencies can take time to rebuild and may require temporary supplementation under the supervision of your doctor. It’s important to determine the root cause of your thyroid imbalance (nutrition imbalance, stress, autoimmune disease etc.) in order to find sustainable solutions.


If you feel your thyroid is out of balance, or would like to learn more, book in for a free 15 minute phone consult.


In health,

Dr. Ashley Damm
Naturopathic Doctor – Vancouver, BC