Hypothyroidism

What is hypothyroidism?

Hypothyroidism is a condition in which the thyroid gland fails to function adequately, resulting in reduced levels of thyroid hormone in the body. Thyroid hormone governs the rate at which many physiological functions take place in the body. Severe hypothyroidism is called myxedema. There are many causes of hypothyroidism. Hashimoto’s thyroiditis, an autoimmune disease of the thyroid gland, is a common cause of hypothyroidism. Some medical treatments, such as surgery or radiation to the thyroid gland, or certain drugs like lithium and phenylbutazone, may also induce this condition. Extreme iodine deficiency, which is rare in the United States, is another possible cause.

Some people with goiter (an enlargement of the thyroid gland) also have hypothyroidism. Goiter can be caused by iodine deficiency, by eating foods that contain goitrogens (goiter-causing substances), or by other disorders that interfere with thyroid hormone production. In many cases, the cause of goiter cannot be determined. While natural therapies may help to some extent, thyroid hormone replacement is necessary for most people with hypothyroidism.

The symptoms of hypothyroidism vary from person to person, but commonly include several of the following: fatigue, lethargy, intolerance to cold, constipation, weight gain, depression, excessive menstruation, dry skin, hair loss, and hoarseness. The onset of these symptoms may be so gradual as to evade detection by patient or physician.

For most of us there is more than one trigger for low thyroid function. The list below highlights a few of the main contributing factors:

• Family History
• Yoyo Dieting
• Chronic High Stress
• Low calorie & nutrient deficient diets
• Hormonal Changes (puberty, childbirth, menopause)
• High Levels of Soya Intake
• Physical Injury

The preferred conventional treatment for hypothyroidism is the synthetic thyroid hormone, levothyroxine (Synthroid®, Levothroid®, Levoxyl®).

Self Help:

Nutritional supplements that may be helpful

• Iodine: Iodine is required by the body to form thyroid hormones, and iodine deficiency can lead to goiter and hypothyroidism. Today, most cases of iodine deficiency occur in developing nations. In industrialized countries where iodized salt is used, iodine deficiency has become extremely rare. Excessive iodine intake can result in either hypothyroidism or hyperthyroidism (overactive thyroid). Sources of iodine include foods (iodized salt, milk, water, seaweed, ground beef), dietary supplements (multiple vitamin/mineral formulas, seaweed extracts), drugs (potassium iodide, amiodarone, topical antiseptics), and iodine-containing solutions used in certain laboratory tests. Many nutritional supplements contain 150 mcg of iodine. While that amount of iodine should prevent a deficiency, it is not clear whether supplementing with iodine is necessary or desirable for most individuals.

Lifestyle changes that may be helpful

• Chemical sensitivities: Preliminary studies have found an association between multiple chemical sensitivities and hypothyroidism. Occupational exposure to polybrominated biphenyls and carbon disulfide has also been associated with decreased thyroid function.
• Lead exposure: One study found a correlation between high blood levels of lead, a toxic substance, and low thyroid hormone levels in people working in a brass foundry. Of the 47 workers tested, 12 were considered hypothyroid; many of these individuals also complained of depression, fatigue, constipation, and poor memory (symptoms of hypothyroidism).

Dietary changes that may be helpful

• Avoid goitrogen-containing food: Some foods, such as rapeseed (used to make canola oil) and Brassica vegetables (cabbage, Brussels sprouts, broccoli, and cauliflower), contain natural goitrogens that may interfere with thyroid hormone synthesis. Cooking has been reported to inactivate the goitrogens in Brussels sprouts.
• Cassava, a starchy root that is the source of tapioca, has also been identified as a goitrogenic food.
• Other goitrogens include maize, sweet potatoes, lima beans, and pearl millet.

Physiology and Clinical Effects

The hormones of the thyroid gland regulate metabolism in every cell of the body. The medical treatment of hypothyroidism (underactive thyroid) usually involves a prescription of synthetic thyroid hormones (thyroxine and/or triiodothyronine) or thyroid extract (desiccated thyroid). The difference between prescription thyroid extract and the thyroid extracts sold as nutritional supplements, is the latter are required by the U.S. Food and Drug Administration to be free of the known active thyroid hormones (thyroxine and triiodothyronine). The use of hormone-free thyroid preparations has not been evaluated in scientific studies, but some doctors believe these products may provide nutritional support to the thyroid gland or contain other compounds with possible hormonal activity.

Food Sources

Thyroid extracts are available as nutritional supplements in capsules and tablets.

Deficiency and Risk Symptoms

As thyroid extract is not an essential nutrient, therefore, no deficiency state exists.

Recommended Dosage

The recommended intake depends on the concentration, method of preparation, and quality of the thyroid extract. Follow the manufacturer’s recommendation on the label.

Contraindications

No side effects or adverse reactions have been reported. However, people taking prescription thyroid hormones should consult their doctor before using non-prescription thyroid extracts.