In hypothyroidism, the purpose of selenium supplementation therapy is mainly to treat certain diseases that cause hypothyroidism and to prevent the aggravation or development of these diseases, but not to treat hypothyroidism. In hypothyroidism many times selenium supplementation therapy is a treatment for the cause of hypothyroidism, especially when there are elevated antibodies against autoimmune thyroiditis and elevated thyroid peroxidase. Some studies have found that selenium supplementation therapy can reduce the level of antibodies and prevent further development of thyroiditis, including the chance of postpartum thyroiditis, which can also be somewhat reduced. Also after selenium supplementation treatment, these ultrasound changes in thyroiditis progress somewhat in a positive direction, so selenium supplementation treatment is considered potentially effective when these diseases that can cause hypothyroidism are present, but there is no direct effect of selenium supplementation in hypothyroidism to improve it.