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Hormones: Thyroid Hormones

Free Book Excerpt: Your Blood Never Lies by James LaValle
August 1, 2016 (Updated: August 3, 2021)
James LaValle

An excerpt from the book, “Your Blood Never Lies: How to Read a Blood Test for a Longer, Healthier Life” by James B. LaValle, RPh, CCN, ND. Read additional excerpts or buy the whole book.

Located in the neck, the thyroid gland produces hormones that control metabolism and energy production. These hormones regulate how each cell converts food into calories and utilizes stored fat to create energy. They influence weight control, nerve and gastrointestinal health, nutrient absorption, and
oxygen use. Initiated by thyroid-stimulating hormone (TSH) from the pituitary gland, thyroid hormone production includes two principal types: the active hormone triiodothyronine (T3) and the inactive hormone thyroxine (T4), which is converted to T3.

In addition to a TSH count, thyroid hormone measurements can include levels of total T3 and T4, and free T3 and T4. Free levels refer to the amount of circulating hormone available for use by your cells, while total levels also include the amount of hormone bound to proteins. Typically, free T3 and T4 readings are considered more reliable indicators of thyroid disturbances than total readings. If your doctor suspects thyroid damage, which is commonly associated with autoimmune conditions such as Hashimoto’s thyroiditis, the lab may test for thyroglobulin antibodies, thyroglobulin AB, or thyroid peroxidase (TPO), which helps convert T4 to T3. Another thyroid hormone called reverse T3, which is typically produced in greater amounts when chronic stress is present, may also be measured. Reverse T3 binds to T3 receptors but does not have any effect. Normal ranges for the main thyroid hormones are listed below.

Thyroid Hormone Normal Range
Thyroid-stimulating hormone (TSH) 0.45 to 4.5 mcIU/mL (microinternational units per milliliter)
Free triiodothyronine (T3) 200 to 440 pg/dL (picograms per deciliter)
Total triiodothyronine (T3) 71 to 180 ng/dL (nanograms per deciliter)
Free thyroxine (T4) 0.82 to 1.77 ng/dL (nanograms per deciliter)
Total thyroxine (T4) 4.5 to 12 mcg/dL (micrograms per deciliter)
Thyroid peroxidase (TPO) 0 to 34 IU/mL (international units per milliliter)

Most doctors request only TSH and T4 levels, following up with a T3 reading if results fall outside out of the normal ranges. Some doctors place great importance on free T3 levels right away, as it is the most active thyroid hormone. If T3 levels are low compared to T4 and TSH levels, it may signify low thyroid function even if the labs otherwise appear normal.


Normally, thyroid levels rise slightly during pregnancy. This is a good thing, as thyroid hormone is critical to the development of a baby’s brain and nervous system. There are, however, unwanted reasons behind elevated thyroid hormones, also called hyperthyroidism, including:

  • Environmental toxins, especially mercury, lead, and cadmium
  • Estrogens
  • Excess iodine in diet
  • Graves’ disease
  • Oral contraceptives
  • Pituitary gland disorder
  • Stress
  • Thyroid nodules
  • Thyroiditis

In addition, certain medications may raise thryoid hormone levels. These substances include:

  • Clofibrate (Atromid-S)
  • Opiate pain relievers like morphine, demerol, and oxycodone

High thyroid hormone levels have been linked to heart disease, osteoporosis, eye problems, and skin conditions. If elevated thyroid hormones are a result of drugs, your doctor will determine how to address the problem. If your thyroid hormones are high, it is essential for you to be evaluated by an endocrinologist.


Symptoms of elevated thyroid hormones include bulging eyes, goiter, irregular heartbeat, anxiety, hand tremors, difficulty sleeping, weight loss, diarrhea, moist skin, muscle weakness, light or missed menstrual periods, and infertility.


High thyroid hormones are a serious issue that will most likely be treated by pharmaceuticals prescribed by your physician. Although it is not often performed unless the situation is unmanageable, the surgical removal of the thyroid gland known as a thyroidectomy may be suggested. While there are lifestyle adjustments that may help alleviate the problem, these will likely be complementary to the treatment recommended by your doctor.


You may wish to consider the following supplements to lower your thyroid hormone levels. Always talk to your physician about possible interactions between supplements and thyroid-reducing drugs. In addition, since bone loss is a common problem in hyperthyroidism, you should ask your doctor about taking a multiple mineral supplement containing calcium and magnesium, as well as vitamin D.

Supplement Dosage Considerations
L-carnitine 2 to 4 g once a day to start; for maintenance, 1 to 2 g once a day. Can help lower triglycerides because it helps move fat into cells for the purpose of energy production. Also supports demineralization and has been reported to reverse and prevent symptoms related to hyperthyroidism. Food sources of the substance are meat, poultry, and dairy products.
Moducare 40 mg (2 capsules) twice a day. Taken if thyroid antibodies are present.
Vitamin D (vitamin D3, or cholecalciferol) 1,000 to 4,000 IU once a day. Vitamin D is necessary for proper calcium absorption. Inform your doctor if you are taking any drug that can deplete vitamin D, such as anticonvulsants, cholesterol- lowering medications, anti-ulcer drugs, or mineral oil. People with kidney disease or atherosclerosis should not take vitamin D. Excessive intake can increase the risk of hardened arteries and high blood calcium levels. People with sarcoidosis, tuberculosis, hyperparathyroidism, and lymphoma should use vitamin D only as directed by a physician. The tolerable upper limit for vitamin D intake is 4,000 IU per day. Higher dosages may be used to treat vitamin D deficiencies, but must be short term and medically supervised.


In the face of high thyroid production, you should stop eating foods that increase inflammation, including fried foods, refined sugar and carbohydrates, preserved or processed foods, artificial sweeteners, dyes or chemical additives, and saturated fats founds in fatty meats and dairy. Additionally, increase your intake of anti-inflammatory omega-3 fatty acids found in low-mercury fish like salmon (pregnant women have to be particularly vigilant when it comes to mercury levels in fish), walnuts, and wild game. Limit exposure to pesticides, antibiotics, and hormones by eating organic produce and free range organic meats. Fruits and vegetables should be favored in your diet. Also consider being tested for food intolerances or beginning an elimination diet to limit exposure to the foods to which your body may be sensitive. This might be a substantial step in taking a proactive approach to managing your thyroid condition, as Hashimoto’s food antigen-induced thyroiditis, for example, is fairly common. You should also be tested for gluten intolerance and celiac disease, as gluten sensitivity is directly associated with an increased risk of both high and low thyroid function.

Because certain chemicals may leach out of products and into your body, do not microwave or drink out of plastic containers, which may have been made with bisphenol A, and do not use personal care products such as shampoos and face creams that contain phthalates. And while drinking two liters of filtered water a day is recommended, stay away from water supplies that contain fluoride or chlorine. Do not smoke, and drink only in moderation. Decrease stress by getting thirty to sixty minutes of exercise three to four times a week. Simply walking, doing yoga, or even gardening can be helpful. Finally, get six to eight hours or uninterrupted sleep per night.

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Chronic Inflammation Decoded


While chronic stress can lower thyroid hormone levels (particularly T3 levels), also called hypothyroidism, often the problem is the result of a more serious factor such as:

  • Environmental toxins, especially mercury
  • Hashimoto’s disease
  • Hypothalamic disease
  • Iodine deficiency in diet
  • Pituitary disease

Pharmaceuticals that can prevent the thyroid gland from functioning properly include:

  • Anabolic steroids (testosterone)
  • Beta blockers
  • Interferon alpha
  • Lithium
  • Phenytoin (Dilantin)
  • Thalidomide

If you notice any symptoms of low thyroid, a blood test is needed to evaluate the reason behind the problem.


A decreased amount of thyroid hormones can result in symptoms that include goiter, chills, cold hands and feet, muscle and joint pain, constipation, depression, weight gain, difficulty losing weight, decline in cognitive function and memory, fatigue, brittle hair and nails, and even hair loss.


In a traditional setting, hypothyroidism is most commonly treated with synthetic thyroid hormones. Low levels of selenium, iodine, tyrosine, and chromium can all play a role in reduced thyroid production, as can low iron and ferritin levels. If dietary changes, nutritional support, and lifestyle adjustments do not help, pharmaceutical options should be considered. Finding a doctor who is knowledgeable about managing thyroid balance can be tricky, so look around your community to locate a doctor with a strong reputation. A doctor worth consulting is one who considers all aspects of thyroid function, including food intolerance—particularly gluten intolerance and celiac disease—environmental burden, micronutrient status, and lifestyle factors such as stress and sleep.


The main drug used to treat low thyroid hormone levels is a synthetic form of thyroxine called levothyroxine (see the table below). Doctors who practice integrative medicine prefer the use of gland-based thyroid extracts because they provide all thyroid hormones in a single compound. However, if you have thyroid antibodies you will not be able to use natural thyroid. Another option is compounded T4 and T3 combined to personalize the thyroid prescription.

Drug Considerations
Armour Thyroid
(prescription thyroid derived from glandular extracts)
Temporary hair loss may occur. See your doctor if you experience symptoms such as increased sweating, sensitivity to heat, tremors, shortness of breath, diarrhea, or mood changes.
Levoxyl, Synthyroid
Must first be converted to T3 in the body, which many doctors see as a shortcoming of the drug. Hair loss may occur at the beginning of treatment and last for a few months. If you experience increased perspiration, sensitivity to heat, tremors, mood swings, shortness of breath, or diarrhea, see your doctor right away.
Triiodothryonine (T3)
Temporary hair loss may occur. See your doctor if you experience symptoms such as increased sweating, sensitivity to heat, tremors, shortness of breath, diarrhea, or mood changes.


The supplements in the table below may combat low thyroid production. If you have hypothyroidism, your doctor will likely prescribe some type of thyroid hormone. Do not take any supplement in combination with this pharmaceutical without first speaking to your physician.

Supplement Dosage Considerations
Fucus (seaweed) 300 to 600 mg once a day. Dosage should contain no more than 150 mcg of iodine a day. Use high quality sea vegetables that have been tested for heavy metals and other contaminants. Do not use if you are pregnant or breastfeeding, or trying to become pregnant. Stop taking at least two weeks before any surgery. Avoid if you have an iodine allergy.
GTF (Glucose Tolerance Factor) chromium 500 mcg twice a day. Helps improve the conversion of T4 to T3. Chromium is also important for blood sugar and insulin regulation. Additionally, people who have a diet high in refined carbohydrates like sugar may also be low in chromium. Use under a doctor’s supervision if you are diabetic, as it may affect medication dosage. Do not use if you have kidney or liver problems, chromate or leather contact allergy, or a behavioral psychiatric condition such as schizophrenia or depression.
Iodine 150 mcg once a day. Clinicians may prescribe higher doses of iodine, but this should be done only under a doctor’s supervision.
Moducare 40 mg (2 capsules) twice a day. Taken if thyroid antibodies are present.
Selenium 100 to 200 mcg once a day. Has been reported to help protect the kidneys. Selenium also helps protect the body against mercury toxicity, which can damage the liver and kidneys. Never take more than the recommended dose. Symptoms of selenium toxicity include vomiting, stomach pain, hair loss, brittle nails, and fatigue.
7-Keto-DHEA 75 to 100 mcg twice a day. Helps improve the conversion of T4 to T3 in tissues.
Tyrosine 250 to 500 mg twice a day. Do not use if you are pregnant or breastfeeding unless under a doctor’s supervision.


Many of the dietary guidelines recommended to fight high thyroid hormone levels also apply to low thyroid hormone levels, such as avoiding foods that cause inflammation, increasing intake of anti-inflammatory foods, eating organic meats and produce, and drinking water that does not contain fluoride or chlorine. Because thyroid production depends on iodine, make sure you get enough iodized salt in your diet, and eat more seafood like shrimp and oysters. Don’t overdo it, though, as too much salt can lead to high blood pressure and heart disease. Add more calcium-rich items to your meals, including leafy green vegetables and organic milk and cheese. Foods that contain selenium and iron may also help. Selenium can be found in whole grains, Brazil nuts, poultry, vegetables, beans, and shellfish.  Foods high in iron include liver, beef, oysters, and turkey.

Do not use plastic containers or personal care items that contain bisphenol A or phthalates, as these chemicals disrupt hormone levels. Reduce stress by exercising for thirty minutes a day three to four times a week, and sleeping for six to eight hours a night.


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