Selenium is a necessary micronutrient needed by the thyroid and has been shown to be beneficial in a number of ways. Many people struggle with hypothyroidism, a group of medical conditions that prevent the thyroid from producing enough hormones to sustain health. Hashimoto’s disease is the most common form of hypothyroidism. In this condition, sometimes referred to as Hashimoto’s autoimmune thyroiditis, the immune system attacks the thyroid gland. A sustained assault on the thyroid eventually leads to inflammation ultimately resulting in poor thyroid function, or hypothyroidism.
Many environmental factors influence the development of hypothyroidism, including gluten, gut health, stress, excess iodine and vitamin D deficiency. We strongly support dietary changes as the first step in the treatment of Hashimoto’s. We also recognize the need for thyroid hormone replacement therapy to ensure a positive outcome in some cases. However, we are interested in new research that shows a strong link between selenium deficiencies and various types of hypothyroidism including Hashimoto’s disease.
While it is uncommon for a healthy adult to suffer a selenium deficiency, a person with a digestive problem may be unable to absorb selenium and other nutrients properly. Someone with Crohn’s disease, serious gastrointestinal inflammation due to infection, celiac and even IBS disease is likely to have low levels of the nutrient.
How Selenium Deficiency Affects Thyroid Function
By itself, a selenium deficiency does not cause any specific condition but it does make the body more susceptible to illness. Selenium plays a strong role in immune function that protects your body from the nutritional, biological and infectious stresses that can make you sick. Selenium optimizes metabolism, supports the synthesis of thyroid hormone and protects the thyroid from damage resulting from overexposure to iodine.
Selenium is essential to the process that converts T4 to T3. As we explain to our thyroid clinic patients, T3 is the active form of thyroid hormone; low T3 levels can cause hypothyroid symptoms. Selenium improves this conversion in a way that causes T4 levels to fall and T3 levels to rise.
A severe selenium deficiency can interfere with this conversion, resulting in low T3 levels and symptoms of hypothyroidism. Research supports our scientific view that selenium supplements are beneficial in the treatment of autoimmune thyroid conditions.
One study shows selenium supplementation positively impacts inflammatory activity in autoimmune disease affecting the thyroid; reducing this inflammation decreases the amount of damage to thyroid tissue. Researchers in this study think this benefit is the result of increases in glutathione peroxidase and thioredoxinreductase activity along with lowered toxic concentrations of hydrogen peroxide and lipid hydroperoxides resulting from thyroid hormone synthesis.
Another study suggests selenium supplements lowered thyroid peroxidase antibody levels in the blood even in people with adequate selenium levels. This study seems to indicate selenium supplementation prevents further thyroid damage, although researchers need to continue working to determine the long-term effects of selenium treatment of inflammatory immune thyroiditis.