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 .
Effects of selenomethionine supplementation on selenium status and thyroid hormone concentrations in healthy adults.
BACKGROUND Selenium , a potential cancer prevention agent currently being tested against prostate cancer in the Selenium and Vitamin E Cancer Prevention Trial ( SELECT ) , plays an integral role in thyroid metabolism . The effects of long-term selenium supplementation on thyroid hormone concentrations are unknown . OBJECTIVE The objective was to investigate the effects of long-term selenium supplementation on thyroid hormone concentrations . DESIGN Twenty-eight healthy adults took 200 microg selenomethionine/d for 28 mo . The thyroid hormones triiodothyronine ( T3 ) , thyroxine ( T4 ) , and thyrotropin ( TSH ) were measured in plasma for 4 mo before supplementation and quarterly during supplementation . The assay methods were changed mid study ; the results of the 2 methods were not comparable . Therefore , one analysis was conducted based on the results of the first method , and a second analysis was based on all of the data , adjusted for the change . Serial data collection permitted a test for trends rather than simply a difference between initial and final values . RESULTS By 9 mo , mean ( + /-SEM ) plasma selenium concentrations had increased from 1.78 + /- 0.07 micromol/L at baseline to 2.85 + /- 0.11 micromol/L for men and from 1.64 + /- 0.04 to 3.32 + /- 0.1.2 micromol/L for women . T3 concentrations in men increased 5 % per year ( P = 0.01 ) . T4 and TSH concentrations were unchanged . CONCLUSIONS Selenium supplementation produced no clinical ly significant changes in thyroid hormone concentrations . A small but statistically significant increase in T3 concentrations was noted in men , with no corresponding decreases in TSH . A subset of SELECT subjects might be monitored periodically for changes during long-term selenium supplementation
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 .