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Issues with Weight? Fatigue? Depression?

Updated: Sep 19, 2018

Many people struggle with their weight. Most probably struggle with losing weight, but there are those who struggle with gaining weight. Most people struggle with their energy levels, meaning they have little to none available. Also, you probably know someone who struggles with depression. There are many possible causes of these issues. One possible cause is abnormal Thyroid function. Let’s discuss some of the factors that make the Thyroid Gland so important.

Hormones and Feedback Loops

The Thyroid Gland is a small gland that is located at the base of the neck and it’s just below the Adam’s Apple. The Thyroid plays a key role in metabolism. It produces several hormones, but the primary ones are Thyroxine (T4) and Triiodothyronine (T3). Some other key hormones for optimal Thyroid function are Thyrotropin-releasing hormone (TRH) and Thyroid-stimulating hormone (TSH).

Proper Thyroid function starts with the brain. The Hypothalamus will release TRH that will travel to the Pituitary Gland. In response to TRH, the Pituitary with release TSH. TSH travels to the Thyroid to tell it to start making Thyroid hormones. The Thyroid produces T4 and T3 in response to TSH. Then the circulating levels of Thyroid hormones should act as a feedback loop telling the Hypothalamus and Pituitary to stop releasing TRH and TSH since Thyroid hormone levels are good. Of course, this assumes that everything is working properly. This whole system is referred to as the Hypothalamic-Pituitary-Thyroid (HPT) Axis.

Here is a diagram showing the HPT axis and the feedback loops. (1)

What if things are not optimal? Let’s look at a common situation that occurs. You go to see the doctor and have different lab tests performed. The results show that your TSH levels are high. What does that mean? It means that your Pituitary Gland is secreting high levels of TSH. It does not tell us why the Pituitary is doing so and it does not tell us where the problem lies. Having other Thyroid hormone levels tested along with Thyroid Antibodies can provide much more information that can be used to see where the problem is. If T4 is low and TSH is high, then you may have an underactive Thyroid, i.e. Hypothyroid. This makes sense with what we have already learned because we see that the Thyroid is not producing hormones appropriately despite the signal being sent by the Pituitary to do so.

Hypothyroidism signs and symptom may include:

  • Fatigue

  • Increased sensitivity to cold

  • Constipation

  • Dry skin

  • Weight gain

  • Puffy face

  • Hoarseness

  • Muscle weakness

  • Elevated blood cholesterol level

  • Muscle aches, tenderness and stiffness

  • Pain, stiffness or swelling in your joints

  • Heavier than normal or irregular menstrual periods

  • Thinning hair

  • Slowed heart rate

  • Depression

  • Impaired memory (2)

You can also see the opposite occur. TSH levels are too low and T4 levels are too high. This suggests that the Thyroid is overactive, i.e. Hyperthyroid. In this example, the Thyroid is continuing to produce hormones, more than what is needed, despite there not being a message from the Pituitary directing it to produce those hormones.

Hyperthyroidism can mimic other health problems and can cause a wide variety of signs and symptoms, including:

  • Sudden weight loss, even when your appetite and the amount and type of food you eat remain the same or even increase

  • Rapid heartbeat (tachycardia) — commonly more than 100 beats a minute — irregular heartbeat (arrhythmia) or pounding of your heart (palpitations)

  • Increased appetite

  • Nervousness, anxiety and irritability

  • Tremor — usually a fine trembling in your hands and fingers

  • Sweating

  • Changes in menstrual patterns

  • Increased sensitivity to heat

  • Changes in bowel patterns, especially more frequent bowel movements

  • An enlarged thyroid gland (goiter), which may appear as a swelling at the base of your neck

  • Fatigue, muscle weakness

  • Difficulty sleeping

  • Skin thinning

  • Fine, brittle hair (3)

If That Is Not Complex Enough…

It sounds like these results should tell us exactly what is wrong and why. Unfortunately, this is not the case. Our bodies are much more complex than that. It is not as “simple” as just hormones and communication. For optimal Thyroid function, our bodies also need many other key components. These include, but are not limited to, Tyrosine (an amino acid), Selenium (a mineral) and Iodine (a chemical element).

T4 and T3 are Tyrosine-based hormones which means that Tyrosine is a precursor to T4 and T3. Recall from earlier, the symptoms of Hypothyroid and Hyperthyroid. Since the Thyroid regulates metabolism of our bodies and most of our cells, we are starting to see why the symptoms are so varied. There also appears to be a connection between the Thyroid and depression. The Thyroid’s role in metabolism and the fact that Tyrosine is a precursor to Dopamine, a neurotransmitter, are starting to explain this connection. (4)

Selenium is a necessary micronutrient. It is actually needed to have the enzymes necessary to convert T4 into T3. If it’s not present in the required amounts, it could result in low T3 and possible hypothyroid symptoms.

T4 and T3 also contain Iodine which makes it essential for these hormones to function properly. Actually, Iodine is a rate-limiting element for the synthesis of Thyroid hormones. (5) This means that if there is not enough iodine present, the rate of Thyroid hormone synthesis slows down or stops. This could result in hypothyroidism or other conditions.

Should I Take Tyrosine, Iodine and Selenium?

That question is harder to answer that you may initially think. All three are good nutrients that our body needs. However, it needs them in the proper amounts. As is often the case, too little of these nutrients is a problem, but so is too much. For example, some people who are experiencing Hypothyroid symptoms may start to supplement with Iodine and do great. Yet, others may get worse. Why is that? Remember earlier when we discussed including Thyroid Antibodies in the lab work to see how the Thyroid is functioning? These antibodies can give us information on whether an Autoimmune issue is the cause of the Thyroid symptoms. In some Autoimmune Thyroid conditions, increased intake of iodine leads to a worsening of symptoms. (5) Also, it is possible to overdose on selenium and experience fatigue, nausea, irritability, hair loss and foul breath as a result. (6)

Do Not Do It Alone

As you can see, it is not that easy to figure out what is needed and how much. This is why it is so important to work with someone and not to guess what the problem and solution are. Form a partnership with the people you work with regarding your health. During this partnership, you can figure out what you need from a diet, lifestyle and supplement perspective, and have the plan tailored to your unique needs. Then, maybe you can more easily achieve your goals regarding your weight, energy levels and/or depression.


This article is for educational use only. Nothing contained in this article should be considered, or used as a substitute for, medical advice, diagnosis or treatment. This article does not constitute the practice of any medical, nursing or other professional health care advice, diagnosis or treatment. Always seek the advice of a physician or other qualified health care provider with any questions regarding personal health or medical conditions. Never disregard, avoid or delay in obtaining medical advice from your doctor or other qualified health care provider because of something you have read in this article. If you have or suspect that you have a medical problem or condition, you should contact a qualified health care professional immediately. If you are in the United States and are experiencing a medical emergency, you should dial 911 or call for emergency medical help on the nearest telephone.


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