Getting to know your thyroid gland

Hypothyroidism is a deficiency of thyroid gland function marked by underproduction of the hormone, thyroxine.

Low functioning thyroid occurs in approximately 10% to15% of the adult population. Mild to severe hypothyroidism occurs in 10% to 12%, while moderate to severe hypothyroidism occurs in 1% to 4% . Hypothyroidism occurs slightly more in females than males.

Hypothyroidism that occurs in children results in delayed physical growth and decreased mental function.

The thyroid gland is one of the largest endocrine glands in the human body and is located in the front and sides of the neck just below the Adam’s apple. It serves as a storehouse of iodine. Thyroxine is the chief hormone produced in the thyroid gland.

The main function of the thyroid gland is to maintain proper growth and metabolism in the human body. Metabolism is a general term used to describe the sum of all physical and chemical processes that occur in the human body. It includes the digestion and absorption of food particles into amino acids, carbohydrates and fats that are used to build and maintain body structure and function.
Body temperature is a reliable indicator of thyroid gland function. The normal oral human temperature is 36.4 C to 37.5 C. Low body temperature below 36.4 C suggests hypothyroidism.

Symptoms of hypothyroidism include physical and mental sluggishness, fatigue, malaise, depression, muscle weakness, forgetfulness, memory impairment, inability to lose weight, weight gain, cold hands and feet, constipation and slow digestion. Other symptoms include swelling and edema, tongue enlargement, brittle and cracked fingernails, dry thin hair.

With females symptoms include menstrual cycle irregularities, prolonged menstrual bleeding, infertility, premature birth and miscarriages. For men, they include, decreased muscle strength, impotence and baldness. High cholesterol and triglycerides, feeling cold, decreased heart rate, an enlarged heart, high blood pressure, impaired kidney function, anemia and delayed tendon reflexes can also occur.

The exact cause of hypothyroidism is not known. Underactive thyroid function, to some degree, may be a process of aging. Heredity can play an important role in its development. Autoimmune disease, where the body’s immune system attacks thyroid gland tissue, is probably the most common cause of hypothyroidism. Other causes include pituitary gland disorders, radioactive iodine therapy, thyroid surgery, congenital deficiency, nerve damage and nutritional deficiencies including iodine, vitamin A, vitamin E, iodine, selenium, zinc and tyrosine.

Excess use of stimulants and dietary supplements can decrease thyroid gland function.

Diagnosis of hypothyroidism is based on history, symptoms and blood tests to determine thyroxine or T4 hormone levels. TSH (thyroid stimulating hormone) is an indirect test that measures pituitary gland function in response to thyroid hormone levels. Additionally, T3 and TPO or thyroperoxidase antibody levels can give useful insight into thyroid gland function.

Conventional medical of treatment of hypothyroidism focuses on drug therapy to replace T4 thyroid hormone levels. Synthetic T4 is the most commonly prescribed and effective medicine. Even though it is synthetic is bio-identical in the sense it has the same chemical structure as naturally produced T4 in the thyroid gland. This hormone must be taken everyday by itself to be effective.

A whole gland thyroid extract derived from beef or pork thyroid glands is often recommended by nutritionally oriented doctors as an alternative to L-thyroxine replacement. The desiccated whole gland extracts contain specific amounts of T3, T4 and other allied residual hormones and nutrients that may be beneficial for thyroid function. It can be used as alternative to T4 replacement in some individuals who want an alternative to L-thyroxine. It is available as a prescription in B.C.

Excessive stress can decrease thyroid gland function. Exercise is a good way to help stimulate metabolism.

A high consumption of raw cruciferous vegetables, including broccoli, Brussel sprouts, kale and cauliflower can decrease thyroid function. Consuming to many soy products can interfere with thyroid gland function. Foods high in iodine, including fish, kelp, seaweed and iodized salt can help improve thyroid function. Consuming excessive amounts of stimulants found in coffee, tea, colas and other caffeine-containing foods, allergy medicine and decongestants can negatively impact thyroid gland function.

Iodine is necessary to make the thyroid hormone. The recommended dietary allowance of iodine is 150 to 200 micrograms per day for most adults. Iodine has been added to refined salt because iodine deficiency was fairy common and contributed to low thyroid function and the development of goitre or an unusual enlargement of the thyroid gland.

The consumption of too much iodine, more than 1,000 mcg per day, can confuse the thyroid gland and can lead to both hypo and hyperthyroid responses.

Nutrients can help support thyroid function. Vitamins and minerals including vitamin A, vitamin E, B vitamins, selenium and zinc are required in small amounts for proper thyroid function.

The amino acid tyrosine is also required to make the backbone of thyroid hormones that are then attached with several iodine molecules.

The information provided in this article is not intended to constitute medical advice. All information and content are for general information purposes only.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.