Excerpt from WHAT YOU MUST KNOW ABOUT WOMEN’S HORMONES
–by Pamela Wartian Smith, MD
Your thyroid gland is your body regulator. Therefore, an imbalance of your thyroid hormone can affect every metabolic function in your body. Your thyroid gland has a lot of important functions.
Functions of the Thyroid Gland and Thyroid Hormone in Your Body
- Affects tissue repair and development
- Aids in the function of mitochondria (energy makers of your cells)
- Assists in the digestion process
- Controls hormone excretion
- Controls oxygen utilization
- Modulates blood flow
- Modulates carbohydrate, protein, and fat metabolism
- Modulates muscle and nerve action
- Modulates sexual function
- Regulates energy and heat production
- Regulates growth
- Regulates vitamin usage
- Stimulates protein synthesis
THYROID HORMONE AND IODINE
Iodine, a chemical element, is particularly important when considering thyroid function. Iodine is an antibacterial, anticancer, antiparasitic, antiviral, and mucolytic agent. Iodine is needed to maintain healthy breast tissue and nerve function, and it protects against toxic effects from radioactive material. According to the World Health Organization, up to 72 percent of the world’s population is affected by an iodine deficiency disorder.
Causes of Iodine Deficiency
- Diets high in pasta and breads (which contain bromide)*
- Diets without ocean fish or sea vegetables (such as seaweed)
- Flouride use, which inhibits iodine binding
- Foods that interfere with iodine: Cabbage, Cauliflower, Rutabaga, Soybeans
- Soil that is depleted in iodine
- Inadequate use of iodized salt (sea salt is not rich in iodine)
- Some medications: Atrovent inhaler (contains bromide), FLONASE (contains fluoride), Flovent (contains fluoride), Ipratropium nasal spray (contains bromide), Pro-Banthine (contains bromide)
- Splenda, a sugar substitute, which contains chlorinated table sugar
- Vegan and vegetarian diets
*Bromide binds to the iodine receptors and displaces the iodine
Contrary to the foods that interfere with iodine, there are plenty of foods that are useful sources of iodine.
Food Sources of Iodine
- Beef liver
- Bread, whole wheat
- Cheese, cheddar
- Cheese, cottage
- Green peppers
- Sardines (canned)
- Tuna (canned)
Be aware, however, that if you intake too much iodine you can get acne. Too much iodine can also cause thyroiditis, an inflammation of the thyroid gland that results in overproduction of the thyroid hormone. Your healthcare practitioner can measure your iodine levels with a urine test.
If you need iodine replacement, it will most likely contain iodine and iodide. Iodine replacement comes in both a liquid and tablet form. Lugol’s solution is a liquid iodine replacement. Iodoral is a tablet that replaces both iodine and iodide. About one-third of people treated for low thyroid function will need to have a lower dose of thyroid medication when the iodine deficiency is corrected.
TYPES OF THYROID HORMONE
It is common for thyroid problems to appear at menopause. Your ovaries have thyroid receptors, and your thyroid gland has ovarian receptors. Therefore, the loss of estradiol (E2) and testosterone from your ovaries that occurs at menopause can have an effect on your thyroid. There are a few different types of thyroid hormones that your body produces.
- Diiodothyronine (T2)
- Thyroid Stimulating Hormone (TSH), which is made in your pituitary gland located in your brain
- Thyroxine (T4), which is made in your thyroid gland
- Triiodothyronine (T3), which is made in other tissues
T4 is 80 percent of the thyroid gland’s production. Most of T4 is converted into T3 in your liver or kidneys. T3 is five times more active than T4.
T4 can also be converted into reverse T3, which is an inactive (stored) form. Taking too much T4 is the most common reason for this.
Additionally, T2 increases the metabolic rate of your muscles and fat tissues.
HYPOTHYROIDISM (LOW THYROID FUNCTION)
Since your thyroid is important to so many functions in your body, it may seem natural that many side effects could result if your thyroid levels aren’t at their optimal amounts.
Symptoms of Low Thyroid Production (Hypothyroidism)
● Agitation ● Allergies ● Anxiety/panic attacks ● Arrhythmias (irregular heart rhythm) ● Brittle nails ● Carpal tunnel syndrome ● Coarse, dry hair ● Cold hands and feet ● Constipation ● Decreased cardiac output ● Decreased memory ● Decreased sexual interest ● Deposition of mucin in connective tissues (this helps the tissues move well) ● Depression ● Diffuse hair loss ● Dizziness/vertigo ● Down-turned mouth ● Drooping eyelids ● Dry, itchy ear canals ● Dull facial expression ● Elbow keratosis ● Endometriosis ● Excess formation of cerumen (ear wax) ● Fat buildup at the clavicle (collar bone) ● Fatigue ● Fibrocystic breast disease (noncancerous changes in the breast tissues) ● Fluid retention ● Gallstones ● Headaches ● High blood pressure ● High cholesterol ● High insulin levels ● Hoarse, husky voice ● Hypoglycemia (low blood sugar) ● Inability to concentrate ● Increase in blepharospasm (eye spasm) ● Increased appetite ● Increased risk of developing asthma ● Increased susceptibility to bruising ● Infertility ● Insomnia ● Intolerance to cold temperatures ● Iron deficiency anemia ● Irregularities in menstrual cycle ● Joint pain or stiffness ● Loss of hair (varying amounts) from legs, arm pit, and arms ● Loss of the lateral (outer) one-third of the eyebrows ● Loss or thinning of eyelashes ● Low blood pressure ● Low body temperature ● Mild elevation of liver enzymes, which affects liver function ● Morning stiffness ● Muscle and joint pain ● Muscle cramps ● Muscle weakness ● Muscular pain ● Nocturia (urinary frequency during the night) ● Nutritional imbalances ● Painful menstrual cycles ● Parathesias (numbness and tingling of the extremities) ● PMS ● Poor circulation ● Poor night vision ● Produces abnormal waves on EEG ● Puffy face ● Recurrent miscarriages ● Reduced heart rate ● Rough, dry skin ● Sleep apnea ● Slow movements ● Slow speech ● Slower reflexes ● Swollen body, especially the legs, feet, hands, and abdomen ● Swollen eyelids ● Tinnitus (ringing in ears) ● Vitamin B12 deficiency ● Weight gain ● Yellowish coloring of the skin
Low thyroid levels can lead to other ailments and problems. For example, low thyroid hormone levels directly affect pregnenolone levels in hypothyroid patients. Mild thyroid dysfunction is also associated with heart disease.
Additionally, thyroid hormones also affect muscle metabolism. If your thyroid is not functioning optimally, you won’t build muscle. As you are likely aware, your muscles are a major part of your body. Some muscles, like the heart, work within the body to pump blood, keeping the body functioning. Other muscles, like the bicep and triceps (in your arms) or the quadriceps (in your leg) serve locomotive purposes, causing movement.
Diseases and Conditions Associated With Hypothyroidism
- Ankylosing spondylitis, a disease where the spine becomes fused and the sufferer has a hard time moving
- Chronic fatigue/fibromyalgia
- Congestive heart failure
- Elevated cholesterol
- Heart disease
- High C-reactive protein
- Increased homocysteine levels
- Insulin resistance
Reverse T3 is a measurement of inactive thyroid function. Reverse T3 has only 1 percent of the activity T3 does. It is an antagonist of T3, which means that the higher your reverse T3 level is, the lower your T3 level will be. T3 and reverse T3 bind to the same receptor sites, so they cannot both occupy these sites at the same time. This situation occurs due to a malfunction of the metabolism of T4. When your reverse T3 is high this is a medical syndrome now called “reverse T3 dominance.”
The most common reason that reverse T3 levels become elevated is stress. When you are stressed, your cortisol levels rise. If you stay stressed all the time your cortisol levels will stay elevated. This phenomenon can cause your body to produce more reverse T3.
Causes of Reverse T3 Dominance
- Autoimmune disease
- Exposure to electromagnetic radiation
- Exposure to environmental toxins such as chemical pollutants, pesticides, mercury, or fluoride
- Food deprivation
- High levels of stress
- Hormonal imbalances (such as high estrogen levels)
- Nutritional deficiencies
- Poor liver function
When you have a high reverse T3 level, you can have any or all of the symptoms of hypothyroidism (low thyroid function) that have been discussed in this chapter. The most common symptom that I see in my practice in patients who have high reverse T3 levels is weight gain. It is very difficult to lose weight and keep it off if your reverse T3 levels remain elevated. Unfortunately, weight gain is also very discouraging. It may make dealing with other problems seem more difficult.
Additionally, when your reverse T3 level is high your body temperature goes down. This slows the action of many enzymes in your body, which can lead to a syndrome called “multiple enzyme dysfunction.”
Symptoms of Multiple Enzyme Dysfunction
- Fluid retention
- Migraine headaches
Consequently, it is very important to have your reverse T3 levels measured. Some scientists believe that the best indicator of thyroid function is the ratio between T3 and reverse T3 since this ratio measures the tissue levels of thyroid hormone.
High levels of reverse T3 can be treated nutritionally. Taking the nutrients that aid the conversion of T4 to T3 is very helpful. Selenium, zinc, vitamins B6 and B12, iron (if levels are low), vitamin D, and iodine have all been found to be helpful. If you are taking T4 supplementation, discontinuing it can also increase T3 and lower reverse T3 levels. However, do not do this without the aid of a physician. Taking a T3 prescription will also increase T3 levels and decrease reverse T3. Furthermore, if you have elevated cortisol levels, lowering them to normal will also diminish your reverse T3.
Decreased production of T3 can cause high cholesterol, because low levels of T3 cause less cholesterol to be removed from your blood. This causes an increase in bad cholesterol. People who have low thyroid levels have cholesterol levels that are 10 to 50 percent higher than people with normal thyroid function.
Inadequate thyroid function can stimulate CYP3A4, a part of the P450 system in the liver, which can cause an increase in production of 16-hydroxy estrone. It can also lead to a decrease in SHBG, which increases the bioavailable amount of E2 and testosterone in the body. Decreased thyroid levels can be caused by a variety of factors.
Sometimes, a deficiency of certain minerals can lead to low thyroid production. There are many elements that can have similar consequences when they are not at their proper levels.
Nutritional Deficiencies That Can Cause a Decrease in T4 Production
- Vitamins A, B2, B3, B6, and C
T4 to T3 Conversion
Your body also needs to be able to convert T4 to T3. T3 is the more active form of thyroid hormone. This conversion requires an enzyme called 5´diodinase.
The inability to convert T4 to T3 will lead to symptoms of thyroid hormone loss. As discussed earlier, T4 also sometimes converts into reverse T3, which can also lead to symptoms of thyroid loss.
Effects of Decreased T3 (or Increased Revere T3)
- Chronic fatigue
- IL-6, TNF-alpha, IFN-2 (immune system factors)
- Increased catecholamines (epinephrine and norepinephrine)
- Increased free radicals
- Prolonged illness
- Toxic metal exposure
- Yo-yo dieting
As mentioned, the conversion of T4 to T3 cannot take place without 5´diodinase, an enzyme. There are many factors that can affect your body’s production of this enzyme.
Factors That Affect 5´diodinase Production
- Cadmium, mercury, or lead toxicity
- Chronic illness
- Decreased kidney or liver function
- Elevated cortisol
- Estrogen excess
- Herbicides, pesticides
- High carbohydrate diet
- Inadequate protein intake
- Oral contraceptives
- Polycyclic aromatic hydrocarbons
- Selenium deficiency
There are other factors besides insufficient 5´diodinase levels that can lead to an inability to convert T4 to T3.
Additional Factors That Cause an Inability to Convert T4 to T3
- Alpha-lipotic acid (too much)
- Calcium excess
- Certain medications: Beta-blockers -Birth control pills -Chemotherapy -Estrogen -Lithium -Phenytoin -Theophylline
- Copper excess
- Deficiency in the following nutrients: Iodine -Iron -Selenium -Vitamins A, B2, B6, and B12 -Zinc
- Dietary factors: Cruciferous vegetables (too many) -Excessive alcohol intake -Low carbohydrate diet -Low fat diet -Low protein diet -Soy -Walnuts
- Inadequate production of adrenal hormones (DHEA, cortisol)
- Phtalates (chemicals added to plastics)
Iron deficiency and physical inactivity impair your body’s response to T3. These factors will also cause you to have symptoms of low thyroid. On the contrary, there are factors that will increase the conversion of T4 to T3 if there is not enough T3 being made by your body.
Factors That Increase the Conversion of T4 to T3*
- Growth hormone
- High protein diet
- Vitamins A, B2, and E
* You may notice that some of the same things that decrease the conversion of T4 to T3 also increase it. This is due to the fact that it is important to have the right amount of these nutrients, herbs, and hormones in your body. Too much or too little will affect thyroid production and subsequently function.
When your doctor sends you for thyroid studies, your entire thyroid panel should be measured—this includes your free T3, reverse T3, free T4, TSH, and your thyroid antibodies. (Tests for T1 and T2 are still in experimental stages and are not available.) If your antibodies are too high, they can stop the thyroid hormone from attaching to the thyroid receptors. Consequently, you can get symptoms of decreased thyroid function—even when your blood levels are adequate.
Thyroid antibodies can be elevated due to trauma, poor function of your gut, inflammation, and thyroid degeneration. Thyroid antibodies are measured by blood. They include thyroid peroxidase antibody (TPOab), thyroglobulin antibody (Tgab), and thyroid stimulating hormone receptor antibody (TRab). If your antibodies are elevated and you have hypothyroidism, this is called “Hashimoto’s thyroiditis,” which is an autoimmune disease. Autoimmune diseases occur when the body is trying to attack itself. With Hashimoto’s thyroiditis, the body is literally attacking the thyroid gland and your body is not producing enough thyroid hormone due to this attack.
There are a number of different hypothyroidism treatments out there. Synthroid and Levothyroxine are both comprised of only T4. Armour Thyroid is made up of T3, T4, T1, T2, and other substances that help the body convert T4 into T3, such as calcitonin, selenium, and diuretic effect. Some physicians feel that Armour Thyroid is not consistent from dose-to-dose. However, there has never been a complaint to the FDA concerning the inconsistency of Armour Thyroid.
If you are diagnosed with hypothyroidism, it is important that your doctor replace both T4 and T3. If you only have your T4 pathway replaced, you may still experience low thyroid symptoms. Replacing T3 and T4 has been found to be more effective than replacing T4 alone in most people. One study revealed that 35 percent of people on T4 and T3 replacement scored better on mental agility tests than people who were just taking T4. Of these people, 67 percent stated they had an improvement in mood and physical health.
Likewise, benefits have been shown by adding T3 for patients already on T4, with the patients reporting better moods and brain function. You can replace both thyroid pathways by adding T3 (Cytomel) to T4 (Synthroid, etc.). Armour Thyroid, which is four parts T4 to one part T3, may not be the right ratio for everyone. If this is the case, your healthcare practitioner can have the T3 and T4 compounded so that your dose is literally made for you, the same way your natural hormones are customized for your needs.
Thyroid medication should be taken on an empty stomach. Eat no food or vitamins for one hour prior to or after taking the medication, since calcium (which is in many foods) interferes with the absorption of thyroid replacement. It is not just dairy foods that are a problem—many other foods contain calcium.
Additional things that alter thyroid absorption are ferrous sulfate (iron), aluminum hydroxide-containing antacids, and medications such as sucrafate and bile acid sequestrants. You may have a hard time tolerating thyroid replacement if you have adrenal fatigue. This is why you should always have your adrenal health evaluated before you are prescribed thyroid medication.
Adrenal dysfunction should be treated before you start thyroid replacement. For this reason, it is important you see a healthcare practitioner who has completed a two-year fellowship in Metabolic/Anti-Aging Medicine and has a Master’s degree in Metabolic and Nutritional Medicine.
Some people develop thyroid resistance due to excess adrenalin production. This is where thyroid receptors (particularly receptors for T3) become desensitized and do not work as well. So, your levels of T3 may be normal or even high, but because the T3 is resistant, you may still have symptoms of low thyroid function. What may also occur is that you take thyroid medication but your body doesn’t tolerate it. In this case, you will experience symptoms of too much thyroid hormone, such as a racing heart and headache.
This is why it’s important your healthcare practitioner always checks your adrenals before starting you on any thyroid treatment. Additionally, low magnesium levels may also interfere with you ability to tolerate thyroid replacement. Chronic exposure to mold can have similar effects. Also, if your gut is healthy, it is easier for your body to assimilate the medication. How you respond to hormone replacement is also associated with your own unique genetic makeup.
Therefore, if you are sensitive to thyroid hormone replacement, you may have a genetic problem with detoxifying. Zinc supplementation has been shown to help with thyroid metabolism. Likewise, taking selenium has been shown in a clinical study to help normalize thyroid function. You may find that you are experiencing symptoms of hypothyroidism, but your blood levels of thyroid hormone are normal. In this case, you should check your basal body temperature, which is the lowest temperature your body reaches during rest.
If your basal body temperature is low (below 97.4ºF), then you may benefit from a low dose of Armour thyroid, even though your blood level is within a “normal range,” but not an optimal range. To check your basal body temperature, take your temperature under your arm for ten minutes when you wake up in the morning before you get out of bed. Record your temperature for three days.
If you are menstruating, check your basal body temperature during your cycle. Ovulation can change your basal body temperature. The body’s temperature goes up with ovulation so that is why it is not recommended to measure basal body temperature during that time. There may be an elevation in temperature due to ovulation, which can skew results if a person really has low temperature, which can indicate low thyroid function.
HYPERTHYROIDISM (EXCESSIVE THYROID FUNCTION)
Contrary to hypothyroidism, your body can produce too much thyroid hormone. This is called hyperthyroidism. The most common cause of hyperthyroidism is Grave’s disease (also known as toxic diffuse goiter). Grave’s disease is an autoimmune disease where the body is trying to attack the thyroid gland. This is very much like Hashimoto’s thyroiditis, although with Grave’s disease the amount of thyroid hormone is being overproduced due to the destruction by the autoimmune process.
Grave’s disease is more common in women than in men. It can occur at any age but is frequently diagnosed between the ages of thirty and forty. There are other less common causes of overproduction of thyroid hormones. Taking too much thyroid medication is one of these, and is called factitious thyroiditis.
If you have a pituitary or thyroid tumor, your body may make an excess of thyroid hormones. You may also have a nodule on your thyroid that overproduces thyroid hormone. This is called “toxic nodular goiter.”
Lastly, some medications can cause drug interactions that can result in an abundance of thyroid production. If you are taking levothyroxine (T4) and the medication Indinavir, this can occur.
Symptoms of Hyperthyroidism
- Chest pain
- Excessive sweating
- Fatigue at the end of the day
- Hair loss
- Heart racing
- Heat intolerance (feeling warm all the time)
- Heightened anxiety, irritability, moodiness, or depression
- Increased bowel movements
- Light or absent menstrual cycles
- Muscle weakness
- Puffiness around the eyes
- Shortness of breath
- Staring gaze
- Thickening of the skin of the lower leg
- Warm, moist skin
- Weight loss
If you have hyperthyroidism, your endocrinologist can use many treatment modalities. If you have mild hyperthyroidism, the amino acid carnitine at 3,000 to 4,000 mg a day may be an effective treatment. There are also foods that suppress the production of thyroid hormone.
Foods That Suppress Thyroid Hormone Production
- Cruciferous vegetables, such as: Broccoli -Brussels sprouts -Cabbage -Cauliflower -Kale
- Leafy green vegetables
Hyperthyroidism can be a life-threatening disease, so it should always be managed by your doctor. If your thyroid hormone production is more than slightly elevated, your healthcare practitioner may need to prescribe a medication.
Medications Used to Treat Hyperthyroidism
- Beta blockers
- Potassium iodide
- Radioactive iodine
If you have mild hyperthyroidism, a high dose of carnitine (an amino acid) of 3,000 to 4,000 mg a day may be helpful. Some people require surgery to treat their hyperthyroidism. However, most people with hyperthyroidism are treated with radioactive iodine, which is given as a capsule. Within six weeks to six months, thyroid function is ablated. This commonly leads to hypothyroidism, or low thyroid function, which will require thyroid medication.
OTHER TESTS OF THYROID FUNCTION
Besides blood studies, your doctor can do some other tests to look at thyroid function.
Thyroid scans are common tests that are done to determine if you have a thyroid nodule (a lump that arises on the thyroid gland) and if the nodule is hot or cold. If you have a goiter (enlargement of the thyroid gland) its size can be measured by a thyroid scan. If you have had thyroid cancer, then a thyroid scan can be used after surgery to see if you have a re-occurrence of cancer. Thyroid scans are also used to see if you have thyroid tissue located outside of the neck. The scan is done by giving a radioisotope (like radioactive iodine) and letting the thyroid gland (or thyroid tissue outside of the thyroid) take up the isotope.
Thyroid ultrasounds are another method of testing thyroid function and assessing thyroid nodules. With this study, sound waves are used to tell if a thyroid nodule is solid or a cyst. However, this test will not tell your doctor if the nodule is cancerous or benign (non-cancerous). If your healthcare practitioner needs more information, you may be sent for a biopsy of your thyroid gland.
About The Author
Pamela W. Smith, M.D., MPH, MS is an internationally known speaker, best-selling author, and educator on subjects of wellness, anti-aging, and functional medicine. Currently, she is the owner and director of the Center for Healthy Living, with locations in Michigan and Florida.
Dr. Smith is the best-selling author of What You Must Know About Vitamins, Minerals, Herbs & More; What You Must Know About Women’s Hormones; What You Must Know About Memory Loss; What You Must Know About Thyroid Disorders; and Why You Can’t Lose Weight.