Let’s talk about hormones! Part 1: The Thyroid

Posted by on Thursday, June 2nd, 2011 in Hormones

Hormones are a common theme in Naturopathic Medicine.  Many people come in with complaints that can be linked back to hormone imbalances.  As such, support around those hormones can have benefits in a number of different areas.

In this posting, I’ll cover some basic information about Thyroid : its biology, the functions of thyroid hormones and the symptoms of dysfunction.  I’ll also chat a little about treatment options.  In future postings, I’ll touch on Growth Hormone, Estrogen and Progesterone and Testosterone.

The thyroid gland sits in front of the windpipe just below the Adam’s apple.  The brain releases two chemincals called TRH and TSH.  TRH is released from an area called the hypothalamus, which then signals for the release of TSH from the pituitary.  TSH tells the thyroid to release two chemicals called T3 and T4.  Higher levels of T4 cause the pituitary to decrease its production of TSH, which acts as a control mechanism for the thyroid.

T3 and T4 are very basic molecules with one amino acid, called Tyrosine and 3 or 4 Iodine molecules.  For such simple hormones, these two are really active in the body.  They control overall metabolic rate, including how the body burns carbohydrates, proteins and fats as well as growth and development.  Thyroid hormone also helps to regulate adrenal hormones and gonadal hormones (ie. estrogen/testosterone).   T3 is extremely active, so the body cleverly protects itself by producing mostly T4 (about 80% of thyroid hormone is T4) and then converting T4 to T3 in the tissues as needed.  Unfortunately, there are many factors that can prevent the body from producing Thyroid hormone but also from converting the less active T4 into T3.  Perchlorates (which are chemicals released from airplane fuel), fluoride and a diet low in iodine decrease the production of T4 and T3.  Stress, fasting and mineral deficiencies will affect the conversion of  T4 to T3.  There are also autoimmune conditions that can either decrease or increase thyroid function.  Adrenal hormones also interact with thyroid balance and often this needed to be addressed along with the thyroid.

So what are symptoms of thyroid dysfunction?  Low thyroid often shows as cold body temperature, dry skin, hair and nails, constipation, joint tenderness, fatigue and depression.  High thyroid is less common but a little more risky with elevated heart rate, sweating, peeling nails, weight loss and eye symptoms.

Thyroid testing is most commonly done by testing TSH.  Unfortunately, as this is the brain hormone, it is an indirect marker of function and can be a little slower to show problems.  The lab reference range for normal thyroid is also very broad, because it is supposed to show overt disease.  But many people feel unwell and like they have low thyroid function with “normal” results.  This is called subclinical hypothyroidism.  Testing TSH as well as T3 and T4 and antibody levels gives a much more complete and helpful picture of function.  Unfortunately, in BC General Practice MD’s are limited to testing TSH for screening and T3 and T4 only if defects come up.  Naturopathic Physicians in BC can order the full panel but this need to be paid out of pocket.

There are many treatments for thyroid function.  Generally, I suggest starting off with nutritional support with low dose iodine, selenium and or L-tyrosine before getting into anything more hefty.  From there we can discuss homeopathics or herbal support to increase thyroid function.  If needed, prescriptions can be good choices.  T4 alone as Synthroid is the most common prescription but many people do better with a little bit of T3 support too.  Prescription thyroid extracts (as USP thryoid, or Armour thyroid) from bovine or porcine (cow or pig) sources with natural T4 and T3 can be good alternatives.

If you suspect thyroid dysfunction consider chatting with your GP or Naturopathic Physician for testing and treatment.  Don’t hesitate to ask for the full panel of testing or for a change in your prescription if you aren’t noticing improvements.

Please stay tuned for upcoming posts on Growth Hormone and Gonadal Hormones.  As always, please feel free to email or comment with questions or ideas for topics.

* Thank you for the use of the thyroid pathway image from http://www.women-health-info.com/236-Thyroid-hormones.html.

~ Dr Kellie

Naturopathic Physician

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