Chronic autoimmune hypothyroidism is one of the most common autoimmune diseases affecting more than 10% of women and 2% of men. It primarily affects those who are 30-50 years old. An elevated thyroid stimulating hormone (TSH) and autoantibodies such as anti-thyroglublin (TgAb) and anti-thyroid peroxidase (TPOAb) are the typical features of this condition. Most hypothyroid disease is an autoimmune process, Hashimoto’s being the most prevalent. A mild hypothyroid condition is called subclinical hypothyroidism with a TSH between 3-6 IU/ml. The American Thyroid Association’s guidelines have a TSH upper limit of 4.12. Some professionals have proposed the TSH should be no higher than 2.5 or 3.0…. while others are even more steering towards 1.5-2.0.
In the current study, a total of 168 patients with Hashimoto’s hypothyroidism with TSH levels between 3 and 6 IU/ml were 
randomized into two groups: one received Myo-inositol 600 mg daily plus 83 mcg of selenium (75 women and 9 men); the other group received just the 83 mcg selenium per day (74 women and 10 men). This was done for 6 months.
TSH, TPOAb and TgAb levels were significantly decreased in patients treated with the combined myo-inositol/selenium after 6 months. There was also a significant increase in free thyroxine (free T4) in the combination supplement group, as well as an improvement in quality of life and subjective symptomatology. The increase in thyroid hormones concentration was observed in both treatment groups, but it was significantly higher in those receiving the combination.
Commentary: The take home in this study is that these doses of myo-inositol plus selenium can improve TSH levels, reduce thyroid antibody levels, and improve subjective symptoms in women and men who have subclinical (a TSH of 3-6) Hashimoto’s thyroid disease. This is great news for those individuals for whom their doctor will not prescribe thyroid hormones because their TSH is normal or normal enough, but yet they have symptoms without other explanations including fatigue, muscle weakness and mood related issues. TSH is a very sensitive marker of thyroid function… more so than thyroid hormone levels such as free T3 and free T4. This is especially true in individuals with subclinical cases. When the TSO is above 10… thyroid hormone prescriptions are a well proven treatment. Of the many mechanisms of myoinositol in thyroid function, it is involved in one of the first steps of thyroid hormone production. Previous trials have reported reduction of TPOAb with selenium after 6 months and we know that selenium deficiency leads to glutathione peroxidase inactivity which may induce oxidative harm for thyroid cells leading to thyroid damage and fibrosis.
Reference: Basciani N. Myo-inositol plus selenium supplementation restores euthyroid state in Hashimoto’s patients with subclinical hypothyroidism. European Review for Medical and Pharmacological Sciences 2017;21(2):51-59
