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 .
The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies.
CONTEXT Pregnant women who are positive for thyroid peroxidase antibodies [ TPOAb(+ ) ] are prone to develop  postpartum thyroid dysfunction ( PPTD ) and permanent hypothyroidism .  Selenium ( Se ) decreases thyroid inflammatory activity in patients with autoimmune thyroiditis . OBJECTIVE We examined whether Se supplementation , during and after pregnancy , influences the thyroidal autoimmune pattern and function . DESIGN This was a prospect i ve , r and omized , placebo-controlled study . SETTING The study was conducted in the Department of Obstetrics and Gynecology and Department of Endocrinology . PATIENTS A total of 2143 euthyroid pregnant women participated in the study ; 7.9 % were TPOAb(+ ) . INTERVENTIONS During pregnancy and the postpartum period , 77 TPOAb(+ ) women received selenomethionine 200 microg/d ( group S1 ) , 74 TPOAb(+ ) women received placebo ( group S0 ) , and 81 TPOAb(- ) age-matched women were the control group ( group C ) . MAIN OUTCOME MEASURES We measured the prevalence of PPTD and hypothyroidism . RESULTS PPTD and permanent hypothyroidism were significantly lower in group S1 compared with S0 ( 28.6 vs. 48.6 % , P<0.01 ; and 11.7 vs. 20.3 % , P<0.01 ) . CONCLUSION Se supplementation during pregnancy and in the postpartum period reduced thyroid inflammatory activity and the incidence of hypothyroidism
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 .