Subclinical Hypothyroidism

Subclinical Hypothyroidism – Controversial Treatment Recommendations Made Clear

Virtually all adults recognize the significance of having appropriate thyroid function, and many people suspect they may have thyroid dysfunction at some time during their lives. They may notice some inexplicable weight gain, fatigue, constipation, dry skin, loss of scalp hair, reduced libido and motivation, or cold intolerance – and their minds wonder if a thyroid gland malfunction is to blame.

Those symptoms are indeed consistent with a person with low thyroid, or hypothyroid, and the standard of care would be thorough testing of the thyroid gland and then an individualized treatment plan according to the results.  The tests one should get include a Free T3 and Free T4, TSH, Reverse T3, anti-TPO, and thyroglobulin antibodies. Optimal TSH is <2.5> and above the bottom of the lab’s reference range. Optimal Free T3 is at least 3.2, and the optimal Reverse T3 is in the bottom of the lab’s reference range.

With this being said, there is a rather special category of hypothyroidism, now known as “subclinical hypothyroidism”. Whether or not subclinical hypothyroidism should be treated is a controversial topic amongst many practitioners. Subclinical hypothyroidism refers to a TSH of 3 or more, but below 10.  The medical societies have recently come to the forefront stating that treatment should be withheld in these cases, as certain studies demonstrated the use of thyroid supplementation made no significant difference in outcome (1).  However, the official recommendation for pregnant women, and in those planning a pregnancy, is to obtain a TSH below 2.0 or 2.5, along with a Free T3 of at least a 3.2. Most functional medicine doctors would argue, if these are the values considered optimal for a pregnancy, why not consider this to be the case in all instances? This mentality, and due to the high likelihood that subclinical hypothyroidism will progress to clinical hypothyroidism, most of these practitioners will recommend and implement personalized treatment at this subclinical stage.

Thyroid malfunction, or simply suboptimal function, is not a good thing for one’s tissues, and patients with mildly reduced thyroid dysfunction cans how some subtle symptoms, often some degree of fatigue. The good news is, to achieve an optimal state of thyroid function, supporting the body’s ability to self-correct with diet and supplements for 6 weeks is often extremely successful, especially when accompanied by a 4 week detox.

Causes of a mildly hypothyroid state can include toxins, stress, autoimmune disease, and nutritional deficiencies. Some ways that toxins, which can disrupt thyroid function, can find their way into the body is through contact with household dust, plastics in contact with food and drink, and vinyl shower curtains. Early age contact with these endocrine disruptors can result in the malformation of thyroid receptors, preventing proper hormone-receptor engagement, and limited or inhibited functionality.

Stress can result in low thyroid function, as the physiological response to stress is to protect the body from a possible famine, by slowing the metabolism, and conserve energy. This happens by increasing the production of reverse T3. Reverse T3 will competitively bind withT3 receptors. So the higher the levels of Reverse T3, the fewer sites left for T3 to bind, effectively lowering the action of thyroid in the body, slowing metabolic functions. There are many ways to address stress. I enjoy guided imagery, while others use mediation, the emotional freedom technique, cognitive behavior therapy, yoga, progressive relaxation, homeopathy, and more! Just be sure to include this important piece of the therapeutic puzzle.

Autoimmune diseases of the thyroid include Hashimoto’s Thyroiditis and Grave’s Disease.  As this paper is focused on subclinical hypothyroidism, we’ll leave the topic of Grave’s Disease for another time. The reasons for the development of Hashimoto’s always will include impaired intestinal gut barrier function (leaky gut) and toxins. There are many such reasons  to begin with a great detox, and also to do the 5 R’s approach to gut healing – Remove, Repair, Replace, Re-inoculate, and Restore the mind and body.

Addressing nutritional deficiencies as a cause of subclinical hypothyroidism with supplementation can also yeild a significantly positive response, most often negating the need for thyroid hormone therapy. As such, the general recommendation is to always begin treatment for subclinical hypothyroidism by addressing the need for essential nutrients, rather than with a hormone prescription, except in pregnancy, where there is need for haste. The nutrients of greatest importance are iodine, selenium, and tyrosine. Iodine is a critically important mineral and deficient in most diets, around the world. It was recognized 100 years ago that iodine was essential for proper thyroid development and function, and that deficiency was not uncommon. This discovery led to the practice of iodine fortification of salt, which was used widely at the time. Fast forward 100 years and iodine deficiency remains prevalent, but few use iodized salt, or any salt for that matter.  There has been a great debate over the dosing of iodine. The lack of iodine in infancy leads to a severe state of mental retardation called cretinism, and in adults to goiters (enlarged thyroid glands) and poor function. As a result, some may believe high-dose iodine supplementation will improve health. However, as with most things in life, the key is finding the optimal dose. The minimum amount to survive is 150 micrograms daily, with 1 mg recommended daily to maintain optimal function. Another important thyroid nutrient is selenium, dosing at 200 mg, or just eat 2-3 Brazil nuts daily is sufficient for most patients. Other essential nutrients for a properly functioning thyroid include the amino acid, tyrosine; zinc; Vitamin E;  Vitamins B2; Vitamin B3; and Vitamin B6;  Vitamin D; Vitamin C; and iron.

If you still feel a bit confused and concerned with the concept and treatment of subclinical hypothyroidism,  remember, with the exception of pregnancy, in which the rule really is to treat with thyroid hormone;  in many cases of subclinical hypothyroidism, treating patients with a protocol to include a course of 4 week detoxification, toxin avoidance, stress management, an excellent diet and judicious supplementation, a prescription for thyroxine is often not needed.


1. Villar, H. C. C. E., Saconato, H., Valente, O., & Atallah, Á. N. (2007). Thyroid hormone replacement for subclinical hypothyroidism. The Cochrane Library.