Introduction
    The thyroid gland, located on the anterior part of the neck, produces two major hormones, thyroxine and triiodothyronine. These hormones are vital activators of metabolism. The thyroid gland is thought to regulate metabolism by affecting the level of cytochrome C, a vital intermediary in metabolism. Hypothyroidism is the word used to describe a group of symptoms associated with underactivity of the thyroid gland.
    According to Dr. Broda Barnes, hypothyroidism afflicts some 80% of the American population. Reduced thyroid activity is a common cause of fatigue, weight gain, impaired thought processes, impaired memory, emotional instability and other serious symptoms.
    Hypothyroidism often goes undiagnosed for several reasons. Physicians often overlook hypothyroidism as a cause for symptoms. If they do consider hypothyroidism, the blood tests used for detection often miss the condition. One may have adequate circulating thyroid hormones and yet have signs and symptoms of hypothyroidism. This occurs because transporters and receptors are needed for the thyroid hormones to act at the cellular level.
    Hair mineral analysis offers a simple, quantitative method for detection of thyroid impairment. It also can offer clues as to the nutritional causes for this common, but very important condition.

Detection Of Hypothyroidism
Blood Tests
    The most common method used to detect hypothyroidism is a blood test. The tests for T3 and T4 measure circulating hormone levels. The TSH test measures the pituitary thyroid-stimulating hormone, which in turn signals the production of T3 and T4.
    Problems with the blood tests are that circulating hormones may be normal, or even high, yet thyroid function at the cellular level may be deficient. This occurs very frequently. For example, elevated tissue calcium stabilizes cell membranes and impairs the transport of thyroid hormone across cell membranes. In other cases, low potassium impairs thyroid hormone activity at the cellular level. Other metabolic defects may also impair thyroid hormone activity at the cellular level.
    In some instances, the body may elevate thyroid hormone levels to attempt to compensate for poor transport across cell membranes. In these cases, a person may have some symptoms of thyroid overactivity such as anxiety. Yet he or she may also have some symptoms of hypothyroidism such as fatigue. The treatment may be drastic, such as removal of the thyroid or permanent damage to the thyroid through irradiation.

The Temperature Test
    Because so many cases of hypothyroidism are misdiagnosed, other detection methods are often superior to blood tests. One of these is the temperature test devised by Dr. Broda Barnes, M.D. He recommends shaking down a thermometer before going to bed and leaving it next to one's bed. In the morning, oral or underarm temperature is recorded immediately upon arising, before getting out of bed. If body temperature is below 97.6 F. on several consecutive mornings, it indicates hypothyroidism.

Hair Mineral Testing
    The other detection method we are familiar with is the use of hair mineral analysis. The hair test has the advantage of being a cellular test. The hair test provides an average reading over a three-month period of time. This is also advantageous because thyroid activity can vary depending on the time of day, or one's activity level.
    The thyroid gland regulates calcium levels. An elevated hair tissue calcium level generally indicates lowered thyroid activity. However, rather than measure calcium alone, our research indicates that the ratio of calcium to potassium is a better indicator. A calcium/potassium ratio greater than 16:1 generally indicates sluggish thyroid activity at the cellular level. Individuals with indicators for both sluggish thyroid and sluggish adrenal glands are called slow oxidizers. A characteristic of slow oxidizers is sluggish thyroid activity.
    Other mineral levels on the hair test such as zinc, copper, cadmium and lead may also indicate thyroid impairment. The effects of these minerals will be discussed later in this article.

Symptoms Commonly Associated With Hypothyroidism
    The most common symptom associated with hypothyroidism is unrelenting fatigue. Other symptoms include:

•	Lump in the throat: This is a symptom of an enlarged thyroid, or goiter. It may cause a sensation upon swallowing or if one clears his throat.
•	Dry Skin and Hair: A hypoactive or sluggish thyroid gland is commonly associated with dry and flaky skin. The skin will eventually lose its tone resulting in saggy, flabby, loose skin. The skin may take on a pallor or pasty appearance. Hair may become dry and brittle and lose its luster. Hair loss may also occur. The fingernails become weak and break easily.
•	Enlarged and grooved tongue: The tongue may enlarge. As this occurs, the constant pressure against the teeth produces indentations which are readily seen when the tongue is extended. The tongue may also quiver when protruded and show signs of geographic tongue or deep grooves running length-wise. The deeper the tooth marks, the more chronic or severe the condition.
•	Weight gain: An unexplained gain in weight or increased difficulty losing weight is a common symptom.
•	Water retention: A common symptom is tightness of rings and at times a noticeable retention of fluid.
•	Constipation: This is a common symptom associated with sluggish thyroid or adrenal glands.
•	Other symptoms: Impaired or disturbed sleep, stiffness upon arising, tenderness to the touch of the thighs, cellulite formation and an increased sensitivity to cold. Other symptoms are a diminished sex drive, atherosclerosis, skin disorders, poor circulation and elevated blood cholesterol.

Nutritional Causes Of Hypothyroidism
    Nutritional research indicates that a variety of imbalances can contribute to thyroid imbalance. Causes include vitamin and mineral deficiencies, heavy metal toxicity, improper diet, use of stimulants, use of prescription and non-prescription medications and other stress factors such as emotional and psychological stress. Let us discuss each of these in more detail.

Vitamin and Mineral Deficiencies
    Vitamins A, B and C are needed for adequate thyroid function. Minerals involved include iodine, manganese, potassium, zinc and copper. Thyroxin is synthesized from iodine and tyrosine. Manganese is thought to be needed to permit this synthesis. Potassium sensitizes the cells to thyroid hormone.
    Copper reduces potassium and decreases thyroid activity, while zinc enhances potassium levels and enhances thyroid activity. The relationships are complex, because elevated tissue copper can actually mimic the effects of an overactive thyroid by stimulating biogenic amine activity. This can give rise to mixed symptoms in persons with metal toxicity. Elevated magnesium and calcium are associated with reduced thyroid activity.

Toxic Metals
    Lead interferes with calcium metabolism and can contribute to thyroid imbalance. Cadmium interferes with zinc and calcium and may raise sodium levels on a hair test. This can contribute to symptoms of thyroid hyperactivity. However, cadmium interferes with other enzyme systems, often causing symptoms of fatigue and lowered thyroid activity.
    Mercury and copper toxicity interfere with thyroid activity and can result in lowered thyroid activity.
"Copper exerts an attenuating (weakening) effect on thyroxin, the secretion of which is diminished in hypothyroidism."
    The use of milk should be avoided inasmuch as "...milk frequently contains copper which it accumulated passing over heated copper rollers while it is being pasteurized, or being transported in copper containers..." --Rodale

Adrenal Exhaustion and Hypothyroidism
    The adrenal and thyroid glands work in close harmony. The adrenal hormones cause the conversion and release of sugars. Thyroid hormone is needed for oxidation or combustion of the sugars. Often hypothyroidism is accompanied by reduced adrenal gland activity. This is revealed on hair mineral tests. Blood tests are not always accurate for detecting adrenal insufficiency.
    The symptoms of adrenal insufficiency are similar to hypothyroidism. In some instances, the thyroid gland attempts to compensate for reduced adrenal activity. This may work for a time, but eventually the thyroid becomes exhausted as well.

Dietary Causes
    Foods high in copper can suppress thyroid activity. These include: avocadoes, liver, soybeans and walnuts.
    Foods or supplements high in calcium can suppress thyroid activity. Dairy products are not only high in calcium, but in fat, which can reduce thyroid activity. High calcium in the diet can lower potassium, a mineral needed to sensitize the tissues to thyroid hormones.
    Goitrogenic foods (members of the cabbage family) contain thiocyanates which inhibit thyroid function. These include Chinese cabbage, broccoli, water cress, kale, rutabaga, turnips, brussels sprouts, cauliflower, radish, horseradish, collard, kohlrabi, rape and mustard greens. These foods should be avoided by individuals suffering from decreased thyroid activity.
    A high fat diet tends to slow the thyroid. Fat tends to slow the metabolic rate.
    Dietary protein has a stimulatory effect on thyroid activity. A diet low in protein results in diminished thyroid activity. In some individuals, an inability to properly digest protein due to a zinc deficiency or a deficiency of hydrochloric acid in the stomach, can lead to lowered thyroid activity.
    Certain amino acids may affect thyroid activity. L-tyrosine can help stimulate production of thyroxin.
    Whole grains are high in phytin. Phytin combines with calcium, magnesium and zinc, resulting in reduced absorption of these minerals. Lowered calcium and magnesium can temporarily stimulate thyroid activity. However, lower zinc and the serotonin-stimulating effect of grains actually reduce thyroid activity.
    Foods that cause a calcium loss may enhance thyroid activity. These foods include citrus fruits, salt and all foods high in sodium.
    "A tendency to retain water and occasionally also sodium chloride, is common in the hypothyroid, particularly in the obese type, while the lean type hypothyroid is more likely to show dry salt retention. Restriction of salt is advisable in both cases. Potassium is often beneficial." --Practical Endocrinology pp. 255
    "What causes all this thyroid trouble? Well, a lot of the problem is in the way we eat. Many of us include salt in our diet, for example, in endocrinology (56:387, 1955), mice tested for goiter-activating foods showed an enlargement of the thyroid could be caused by salt. With omission of salt, goiters decreased in size..." --EOCD pp.760
    Salty foods tend to lower magnesium, which enhances thyroid activity. Many people mistakenly avoid all salt in their diet. Adding back a reasonable amount of sea salt can often improve symptoms of hypothyroidism.
    Alcohol causes a magnesium loss from the body. Since magnesium acts as a brake on thyroid activity, alcohol can cause a temporary increase in thyroid activity.

The Water We Drink
    A hidden cause of thyroid underactivity is drinking water with added chlorine and fluoride. These minerals suppress thyroid function. If your drinking water is high in either chlorine or fluorine, a water purifier should be utilized to eliminate these thyroid-suppressants.

Medications and the Thyroid
    Certain medications, including aspirin, have a suppressant effect upon the thyroid gland.
    "The Journal of Endocrinology (November, 1953) tells us that aspirin, . . . has an immediate anti-thyroid action and hypothyroidism is often the result of its use." --EOCD, pp. 760

Stimulants and Hypothyroidism
    Many stimulants such as sugar, caffeine, cocaine and others temporarily increase thyroid activity by increasing sympathetic nervous system activity. However, when the stimulant dose wears off, a rebound action causes lowered thyroid activity. This can happen after one dose, or may happen as a result of years of use of more mild stimulants.

Autonomic Response, Stress and Hypothyroidism
    The thyroid is activated by the sympathetic nervous system as part of the fight-or-flight response to stress. If the autonomic nervous system is excessively sensitive or overstimulated, overstimulation of the thyroid occurs. The first effect is an increased thyroid and adrenal response. This may continue for several hours, days or years, depending upon its intensity. Then the thyroid weakens and can no longer maintain its response. Hypothyroidism then results.
    This chain of events is labeled the General Adaptation Syndrome by Dr. Hans Selye, M.D. The alarm response, including excessive thyroid activity, is the first stage of adaptation. During the resistance and exhaustion stages, the thyroid weakens and hypothyroidism occurs.
    This type of hypothyroidism can be caused by any type of stress. Eventually the thyroid becomes nutritionally depleted and cannot function properly. If the autonomic nervous system is out of balance, the thyroid is not properly stimulated by the pituitary to produce adequate amounts of thyroid hormone.

Correction Of Hypothyroidism
    The common treatment of hypothyroidism involves hormone replacement with either natural bovine thyroid hormone (Armour thyroid) or with synthetic hormones (Synthroid, Cytomel, etc.). In some cases, this corrects the symptoms. This treatment, however, does not correct the cause of the problem. The patient usually is told he or she must remain on the hormones for life.
    In many cases, hormone replacement does not clear up all the symptoms. This occurs for several reasons:

•	Symptoms may be caused by adrenal as well as thyroid underactivity. Both the adrenal and thyroid imbalances must be corrected.
•	The cause of symptoms is an autonomic nervous system imbalance, which affects far more than just the thyroid gland.
•	Thyroid hormones are adequate, but do not reach the cells, the target site for the hormone. This may be due to low tissue potassium, elevated tissue calcium and magnesium, or the presence of toxic metals.
•	An improper diet can offset the effects of the hormones.
•	Overwhelming stress or nutritional deficiencies prevent a satisfactory response.