Feeling lethargic, depressed, or exhausted for no apparent reasons. Think thyroid. Thyroid disease affects 27 million individuals. The thyroid is responsible for regulating temperature, heart rate, and carbohydrate and fat metabolism. The physiology revolves around a negative feed back loop. Initially, the hypothalamus releases thyroid releasing hormone, targeting the pituitary gland releasing the thyroid stimulating hormone targeting the thyroid gland, releasing thyroxine hormones of T3 and T4 with T3 being the most potent. T4 is converted to T3 in periphery by the 5 deiodinase enzyme. This enzyme is nutritionally dependent just as the overall thyroid physiology. Therefore treatment and prevention of the symptoms rely on both medical and nutritional management.
Prior to treatment and prevention, it is significant to understand symptoms and diagnosis. Thyroid conditions present along a continuum. Thus, subclinical hypothyroidism to overt hyperthyroidism exists. For example, objectively, the clinical markers are the thyroid stimulating hormone and the free thyroxine or T4 levels. References ranges for these markers are 0.2-5.5 mIU/L TSH and 9.8-25 pmIU/L T4. Thus, the trend is elevated TSH and low T4 reveals hypothyroidism as low TSH and elevated T4 reveals hyperthyroidism. Subjectively, a low thyroid manifests as lethargy, avolition or low motivation, constipation, cold intolerance, reduced appetite, depression, fatigue, and weight gain. A high thyroid manifests as anxiety, weight loss, tremors, mood instability, and heat intolerance or sweating.
Once a diagnosis is confirmed based on symptomatic focus with supporting laboratory data, treatment and prevention are essential. In fact, nutrition is extremely significant in correcting the imbalances along with medication. Some of the minerals important to thyroid production include zinc, iodine, iron, and selenium. Specifically, iron, iodine, and zinc are critical components to thyroxine production. Selenium is a co-factor for 5 deiodinase enzyme and thus necessary for T4 to T3 conversion. In addition, a reduced carbohydrate and rich protein diet improves thyroid function as well.
Many times thyroid specific diets are not enough to correct the imbalances. Thus, at this time, medications become key. These medications are thyroid replacements. For example, they supply T4, T3, or mixture to the patient. Levoxyl or Synthroid (levothyroxine) is synthetic T4 replacement. Cytomel (liothyronine) is synthetic T3 replacement. Armour thyroid is dessicated or “natural.” The standard of care revolves around consistency and American Thyroid Association as well as American Clinical Endocrinologists recommend synthetic T4 replacement.
Once homostasis results, many comorbid conditions correct as well. Thyroid is associated with mood instability, gastrointestinal dysfunction, and cardiovascular morbidities. Thus, depression and anxiety resolve, absorption enhances, irritation reduces, and heart function improves. Therefore, thyroid monitoring is imperative. The monitoring frequency and intensity depends on physician, however, every 4-6 weeks initially to every 3-4 months thereafter and based on symptoms.
Often times, the correction may potentiate overactive thyroid and result in hyperthyroidism either temporarily or permanently. Thyroid is extremely sensitive organ. Its function controls many body systems and thus should never go unattended.
In conclusion, although tiny, the thyroid gland is mighty. Never underestimate its power! Think thyroid in troubling, unexplainable, multi-symptom conditions. Request laboratory orders to confirm and establish a strong rapport with physician.
Pharm D, BCPS, BCACP, CDE, MSMTM, BSN, CPTT