Here is a news article regarding a presentation by one of the researchers.   It is a little easier to understand than the abstract which is also below.   The full research article can be viewed in this PDF file.   More than half of the patients feel better with the selenium supplements.  Finally, at the bottom of this page is an old map showing selenium distribution in the US and Canada.

By Emma Patten-Hitt
Special to DG News

DENVER, CO -- June 22, 2001 -- Selenium supplementation may prevent progression of autoimmune thyroid disease, especially during the onset of the disease, according to researchers.

Dr. Barbara Gasnier with the Medizinische Klinik University, Munich, Germany, reported the findings today at the 83rd Annual Meeting of the Endocrine Society (ENDO) in Denver, Colorado.

According to the researchers, selenium deficiency may contribute to the development and maintenance of autoimmune thyroiditis because of its effect on the function of selenium-dependent enzymes, which can modulate the immune system.

Dr. Gasnier and her colleagues performed a blinded, placebo-controlled, prospective study in 72 women with autoimmune thyroiditis, average age 42, with thyroid peroxidase antibodies and/or thyroglobulin antibody levels greater than 350 U/mL.

Patients were randomized into two groups matched in aged and antibody levels. A total of 36 patients received 200 mcg of sodium selenite per day for three months, and 36 patients received placebo. All patients were substituted with L-thyroxine to maintain thyrotrophin (TSH) levels within the normal range.

The researchers then measured the change in the autoantibody concentration as a marker for the activity of the disease.

After three months, nine patients in the selenium treated group had completely normalized antibody titers in contrast to only two patients in the placebo group. In addition, the mean thyroid peroxidase antibody concentrations decreased significantly to 51 percent in the selenium group compared to 90 percent in the placebo group. The thyroglobulin antibodies concentrations, a marker of humoral immunity, were unchanged in both groups, however.

The effect was more pronounced in patients with high thyroid peroxidase antibody concentrations. An analysis of eight patients with concentrations greater than 1200 U/mL indicated a 40 percent reduction in the selenium treated patients compared to a 10 percent increase in the placebo group.

"Selenium substitution with 200 mcg of sodium selenite may improve the inflammatory activity in patients with autoimmune thyroiditis," the researchers noted, but "whether this effect is specific for autoimmune thyroiditis or may also be effective in other organ-specific autoimmune diseases has to be investigated."

"With selenium supplementation, we may be increasing peroxidase activity, thereby lowering free radicals, which contribute to inflammation," Dr. Gasnier explained.

"Selenium supplementation may be necessary only in certain countries where selenium levels in the soil are low," Dr. Gasnier told Doctor’s Guide. "In Europe, China and Central Africa, there is a lack of selenium in the soil, so supplementation may be more important in these areas compared to others," she said.

Selenium Supplementation in Patients with Autoimmune Thyroiditis Decreases Thyroid Peroxidase Antibodies Concentrations

Department of Endocrinology, Medizinische Klinik Innenstadt, University of Munich, D-80336 Munich, Germany

Address all correspondence and requests for reprints to: Prof. Dr. Roland Gärtner, Medizinische Klinik Innenstadt der Universität München, Ziemssenstrasse 1, D-80336 Munich, Germany. E-mail: . rgartner@medinn.med.uni-muenchen.de

Abstract

In areas with severe selenium deficiency there is a higher incidence of thyroiditis due to a decreased activity of selenium-dependent glutathione peroxidase activity within thyroid cells. Selenium-dependent enzymes also have several modifying effects on the immune system. Therefore, even mild selenium deficiency may contribute to the development and maintenance of autoimmune thyroid diseases. We performed a blinded, placebo-controlled, prospective study in female patients (n = 70; mean age, 47.5 ± 0.7 yr) with autoimmune thyroiditis and thyroid peroxidase antibodies (TPOAb) and/or Tg antibodies (TgAb) above 350 IU/ml. The primary end point of the study was the change in TPOAb concentrations. Secondary end points were changes in TgAb, TSH, and free thyroid hormone levels as well as ultrasound pattern of the thyroid and quality of life estimation. Patients were randomized into 2 age- and antibody (TPOAb)-matched groups; 36 patients received 200 µg (2.53 µmol) sodium selenite/d, orally, for 3months, and 34 patients received placebo. All patients were substituted with L-T₄ to maintain TSH within the normal range. TPOAb, TgAb, TSH, and free thyroid hormones were determined by commercial assays. The echogenicity of the thyroid was monitored with high resolution ultrasound. The mean TPOAb concentration decreased significantly to 63.6% (P = 0.013) in the selenium group vs. 88% (P = 0.95) in the placebo group. A subgroup analysis of those patients with TPOAb greater than 1200 IU/ml revealed a mean 40% reduction in the selenium-treated patients compared with a 10% increase in TPOAb in the placebo group. TgAb concentrations were lower in the placebo group at the beginning of the study and significantly further decreased (P = 0.018), but were unchanged in the selenium group. Nine patients in the selenium-treated group had completely normalized antibody concentrations, in contrast to two patients in the placebo group (by ² test, P = 0.01). Ultrasound of the thyroid showed normalized echogenicity in these patients. The mean TSH, free T₄, and free T₃ levels were unchanged in both groups.

We conclude that selenium substitution may improve the inflammatory activity in patients with autoimmune thyroiditis, especially in those with high activity. Whether this effect is specific for autoimmune thyroiditis or may also be effective in other endocrine autoimmune diseases has yet to be investigated.

Map of Selenium Status in US & Canada

This is a very old map (Kubota et al., 1967). While the areas showing deficient may still be correct, there have been other areas deficient in selenium that have been identified that are not represented on this map.

"Selenium deficiency is a major problem for livestock or wildlife in at least 37 states and costs beef, dairy, and sheep producers an estimated $545 million in losses every year. " soil scientist Gary S. Bañuelos