The effect of dietary supplementation with selenium on the course of autoimmune thyroiditis- a review of clinical trials conducted in the European population

Many observations indicate the existence of a relationship between reduced selenium status in the body and various thyroid diseases, including autoimmune thyroiditis. In most studies devoted to this issue, change in concentration of anti-TPO antibodies was the main measure of the effectiveness of selenium supplementation in patients with autoimmune thyroiditis. The concentration of anti-TPO has an impact on the intensity of lymphocytic infiltration in the thyroid gland and the degree of damage to this gland; therefore, reducing their concentration as a result of increased selenium consumption may contribute to more effective treatment of autoimmune thyroiditis. In some works, the evaluation of immunoregulatory effect of selenium in the course of autoimmune thyroiditis was considered in relation to a wider range of biochemical and immunological parameters (mainly changes in the production of cytokines and chemokines). Many authors have confirmed the effect of selenium on reducing the concentration of anti-TPO, but pooled results of all the studies are ambiguous. The discrepancy may have been caused by a different degree of saturation of the thyroid with selenium and iodine in patients, a different severity of the disease, different doses of selenium administered to patients, the use or non-use of simultaneous therapy with L-thyroxine, and single nucleotide polymorphisms (SNPs) occurring in genes encoding particular selenoproteins. Based on literature, it can be concluded that the issue concerning the role of selenium in autoimmune thyroiditis is still poorly understood. There is a need to continue research evaluating the effect of selenium on the course of this disease, which should include also other parameters apart from anti-TPO. The results of such extensive research may be helpful in formulating new guidelines for supporting treatment by appropriate modification of diet, including selenium supplementation.

Automated summary

The relationship between selenium and autoimmune thyroiditis is not fully understood, and further research is needed to clarify its mechanisms. Supplementation of selenium may help in treating the disease more effectively by reducing the concentration of anti-TPO, but the overall results from studies are inconclusive.