My integrative medicine approach to Hypothyroidism

The thyroid is the butterfly-shaped gland at the base of your neck that produces hormones important for regulating metabolism, body temperature, energy, heart rate, menstrual cycle, mood, and hair and nail growth.

Hypothyroidism is associated with a deficiency in the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Since these hormones influence every cell in the body, hypothyroidism can have wide-reaching impacts, including slowing metabolic processes. This can result in fatigue, weight gain, decreased body temperature, hair thinning, constipation, brain fog, and fluid retention.

Untreated or inadequately managed hypothyroidism can lead to more serious health concerns such as cardiovascular issues and neurological and musculoskeletal symptoms.

The thyroid functions within a complex system of signals coordinated by the brain, interacting with several nutrients and other hormones. The hypothalamus in the brain is responsible for managing hunger, thirst, sleep, hormones, and body temperature and monitors the level of thyroid hormone in the blood. When it detects the need for increasing metabolism and energy, it releases Thyroid Releasing Hormone (TRH) to signal the pituitary gland at the base of your brain to release Thyroid Stimulating Hormone (TSH).

TSH acts directly on the thyroid, stimulating it to produce and release thyroid hormones. To do this, the thyroid uses the amino acid tyrosine and iodine to manufacture and convert thyroid hormones T4 and T3.

• T4: a storage form of thyroid hormone that circulates throughout the blood and is stored in tissues for when it is needed
• T3: the active form of thyroid hormone

When different parts of the body need active T3, they convert the storage T4 to active T3 using an enzyme called deiodinase. T3 can then act on cells to support energy production and regulate metabolism.

When the thyroid does not produce enough hormones or the hormones it produces cannot act effectively, this impacts cells throughout the body, causing symptoms such as:

• Fatigue
• Weight gain
• Headaches and migraines
• Thinning or dry hair, nails, and skin
• Brittle nails
• Feeling cold all the time and decreased body temperature
• Irregular periods
• Puffiness or fluid retention
• Slowed heart rate
• Fertility problems
• Low libido
• Slow digestion and constipation
• Brain fog
• Depression
• Aching muscles and joints
• Loss of muscle strength and tone

Especially early on in the condition, these symptoms may be vague and seem common in our busy society, delaying diagnosis.

Over time, untreated hypothyroidism can lead to additional complications, including:

• Elevated cholesterol
• Heart disease and heart failure
• High blood pressure
• Problems during pregnancy
• Myxedema, a rare, serious condition where the body’s functions slow down significantly

Hypothyroidism can result when the thyroid gland is underactive and not producing enough thyroid hormones, or the thyroid hormones cannot work properly in the peripheral tissues. This can happen for several reasons.

• The pituitary gland malfunctions and does not send enough Thyroid Stimulating Hormone (TSH) to the thyroid.
• TSH levels are normal, yet the thyroid does not produce enough T4 and T3 to adequately stimulate cells due to nutritional deficiencies, malfunction, or other factors.
• The peripheral receptors do not respond appropriately to thyroid hormones.

Autoimmunity

In iodine-sufficient countries like the United States, Hashimoto’s, an autoimmune thyroid disorder, is the most common cause of hypothyroidism, impacting many Americans, primarily women. This is an autoimmune condition where the body produces antibodies that affect the thyroid gland, impairing the thyroid’s ability to produce thyroid hormone over time.

Some of the main factors contributing to autoimmunity and the development of Hashimoto’s disease include imbalances in gut health, nutrition, infections, environmental exposures, and genetics.

Iodine Deficiency

Globally, low iodine in the diet is a leading cause of an under-functioning thyroid gland. Iodine is a trace mineral found in seafood, seaweed, plants grown in iodine-rich soil, and iodized salt and is needed for the production of thyroid hormones. Too little iodine can lead to hypothyroidism since the gland cannot adequately produce T3 and T4.

*It’s important to note that too much iodine can also affect hypothyroidism in people who already have the condition, so it’s vital to work with your provider before supplementing iodine.

Environmental Factors

Environmental factors such as heavy metals and endocrine-disrupting chemicals (EDCs), often found in foods, food packaging, water, and personal care products, can interfere with thyroid gland functioning and thyroid hormone transport through multiple mechanisms.

Past or ongoing exposures to heavy metals, mercury, arsenic, cadmium, solvents, plastics, and pesticides may contribute to an imbalance of gut bacteria (dysbiosis), inflammation, and autoimmunity by affecting the body’s detoxification, digestive, nervous, and endocrine systems.

Certain chemicals such as fluoride and bromine in municipal water supplies, flame retardants, and some baked goods can directly compete with iodine in the thyroid gland, impacting its functioning.

Postpartum Thyroiditis

Postpartum thyroiditis happens when a woman’s thyroid gland becomes inflamed after having a baby. Postpartum thyroiditis may first make your thyroid overactive (hyperthyroidism), but over time the condition leads to an underactive thyroid (hypothyroidism). Postpartum thyroiditis affects some women in the first year after giving birth. The condition is typically temporary, but it’s essential to screen thyroid function in women during and after pregnancy.

Chronic Dieting (particularly when paired with excessive exercise)

Extended periods of low-calorie diets are associated with increased stress hormones and decreased thyroid hormone, resulting in less-than-optimal thyroid function and its symptoms. While exercise is essential to a healthy lifestyle, the “dose” matters, and it’s vital to fuel the body appropriately.

Radioactive iodine or anti-thyroid medications are often used to manage hyperthyroidism when too much thyroid hormone is produced. If hyperthyroidism is over-corrected, it can lower thyroid hormone production too much, resulting in hypothyroidism.

Drug-Induced Hypothyroidism

Drug-induced hypothyroidism is when a medication you’re taking affects your thyroid gland, producing less thyroid hormone. It’s important to find a balance where your levels aren’t too high or too low and discuss with your doctor if you start noticing hypothyroid symptoms after starting a new medication.

Thyroid Surgery or Radiation

Removing all or a large portion of the thyroid gland via surgery or affecting it via radiation treatments can lead to hypothyroidism.

A failure of the pituitary gland to produce enough thyroid-stimulating hormone (TSH) results in the thyroid gland not producing enough thyroid hormones. This usually occurs due to a benign pituitary gland tumor, inflammation of the pituitary gland, or elevated pressure in the brain that affects the pituitary gland.

Functional medicine testing can help identify the underlying factors contributing to hypothyroidism. This includes assessing the functioning of the thyroid, measuring thyroid-supporting nutrients, and evaluating factors that play a role in immune system function to uncover the causes of the autoimmunity leading to Hashimoto’s disease when that is the cause.

Thyroid function and Autoantibodies

To assess the state of thyroid function, a Complete Thyroid Panel including thyroid-stimulating hormone (TSH), T3 (free and total), T4 (free and total), reverse T3, and thyroid peroxidase (TPO) and anti-thyroglobulin (TG) and antibodies should be assessed using functional medicine ranges.

Compared to conventional lab ranges, which are based on results from the overall population, functional medicine thyroid lab ranges are tailored to detect thyroid issues prior to the onset of more advanced thyroid disease.

• TSH measures how the pituitary gland in the brain is communicating with the thyroid and is indicative of hypothyroidism when elevated. A normal TSH does not rule out thyroid issues on its own since it is an indirect but specific measure of thyroid function.
• Free T4 measures the bioavailable or unbound thyroid hormone and is a marker of low thyroid function when decreased.
• In the peripheral tissues, T4 is converted to T3. A low level of T3 can indicate low thyroid function or a problem with conversion, which often occurs with chronic stress, inflammation, or a high toxic burden.
• Some T4 is also converted to reverse T3, which serves as a “brake” since it competes with free T3 for cell receptor sites. High levels of reverse T3 can be associated with hypothyroidism and usually reflect a systemic issue like chronic inflammation.
• In addition, thyroid antibody testing for thyroid peroxidase (TPO), anti-thyroglobulin (TG), and antibodies are key for assessing Hashimoto’s disease.
• In addition to elevated TPO antibodies, typically found in Hashimoto’s disease, thyroglobulin antibodies may also be high, although commonly, these antibodies are associated with Grave’s disease or autoimmune hyperthyroidism.

Micronutrients

Micronutrient testing analyzes vitamins, minerals, and other nutrients required for proper immune function and thyroid health. Nutrients including iodine, iron, tyrosine, zinc, selenium, magnesium, and vitamins E, B2, B3, B6, C, and D all contribute to the proper production of thyroid hormones, and some of these, including zinc and selenium, are also important for supporting the conversion of T4 to T3. Other nutrients like vitamin A improve cellular sensitivity to thyroid hormones.

*Iodine can also be assessed in the urine.

Gut Health

Since dysbiosis and leaky gut are factors in developing autoimmune diseases like Hashimoto’s and overall inflammation that can impact the thyroid, assessing gut health can help provide targeted interventions.

A Comprehensive Stool Test measures amounts of healthy and unbalanced gut bacteria (dysbiosis), inflammatory markers, leaky gut, parasites, and yeast to assess the state of the gut and guide approaches aimed at restoring balance.

Additional testing for gluten sensitivity or celiac disease and evaluation of the leaky gut marker zonulin can also help to guide approaches.

Food sensitivities can contribute to increased intestinal permeability, inflammation, and autoimmunity. Foods to which an individual is sensitive can be identified with ELISA testing.

Factors that Influence Detoxification

An individual’s ability to detoxify and effectively clear toxins from the body can impact thyroid function.

Methylation, detoxification capacity, and glutathione production can be assessed with specialized labs to understand an individual’s genetic susceptibilities and current detoxification capacity. This can help to pinpoint areas that can be supported to bring the body and metabolism back into balance.