Two systematic review s have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies .
The immunomodulatory effects of selenium might involve reducing proinflammatory cytokine release .
In Graves ’ disease , some , but not all , trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism , and might benefit patients with mild Graves ’ orbitopathy .
The available evidence from trials does not support routine selenium supplementation in the st and ard treatment of patients with autoimmune thyroiditis or Graves ’ disease .
However , correction of moderate to severe selenium deficiency may offer benefits in preventing , as well as treating , these disorders .
Purpose of review This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases , and discusses possible effect mechanisms .
Recent findings Epidemiological data suggest an increased prevalence of autoimmune thyroid diseases under conditions of low dietary selenium intake .
However , clinical ly relevant effects of selenium supplementation , including improvement in quality of life , are more elusive .
Selenium in the treatment of autoimmune thyroiditis
We recently conducted a prospect i ve , placebo‐controlled clinical study , where we could demonstrate , that a substitution of 200 μg sodium selenite for three months in patients with autoimmune thyroiditis reduced thyroid peroxidase antibody ( TPO‐Ab ) concentrations significantly . Forty‐seven patients from the initially 70 patients agreed to participate in a follow‐up cross‐over study for further six months . One group ( n = 13 ) , which initially received selenium continued to take 200 μg sodium selenite ( Se‐Se ) , one group stopped taking selenium ( Se‐0 ) ( n = 9 ) , another group which received placebo started to take 200 μg selenium ( n = 14 ) ( Plac‐Se ) and the last group was without selenium substitution ( Plac‐0 ) ( n = 11 ) . TPO‐Ab concentrations were measured at beginning and the end of the study . In the Se‐Se group , the TPO‐Ab concentrations further significantly p = 0.004 ) decreased from 625 ± 470 U/ml to 354 ± 321 U/ml , in the Se‐0 group the TPO‐Ab concentrations increased significantly p = 0.017 ) from 450 ± 335 to 708 ± 313 U/ml . In the placebo group , the TPO‐Ab concentrations in those patients who were followed without selenium substitution were unchanged ( 1351 ± 940 vs. 1724 ± 1112 U/ml , p = 0.555 ) . In contrast , the patients who received 200 μg sodium selenite after  placebo , the TPO‐Ab concentrations decreased significantly ( p = 0.029 ) from 1182 ± 723 to 643 ± 477 U/ml
Two systematic review s have evaluated controlled trials among patients with autoimmune thyroiditis and report that selenium supplementation decreases circulating thyroid autoantibodies .
The immunomodulatory effects of selenium might involve reducing proinflammatory cytokine release .
In Graves ’ disease , some , but not all , trials indicate that adjuvant selenium supplementation enhances the restoration of biochemical euthyroidism , and might benefit patients with mild Graves ’ orbitopathy .
The available evidence from trials does not support routine selenium supplementation in the st and ard treatment of patients with autoimmune thyroiditis or Graves ’ disease .
However , correction of moderate to severe selenium deficiency may offer benefits in preventing , as well as treating , these disorders .
Purpose of review This review provides an appraisal of recent evidence for or against selenium supplementation in patients with autoimmune thyroid diseases , and discusses possible effect mechanisms .
Recent findings Epidemiological data suggest an increased prevalence of autoimmune thyroid diseases under conditions of low dietary selenium intake .
However , clinical ly relevant effects of selenium supplementation , including improvement in quality of life , are more elusive .