Context: Selenium is an essential micronutrient for human
beings. Selenoproteins play a role in anti-oxidation and in maintaining immunity. Selenoproteins are distributed in all tissues - the most important of which are glutathione peroxidase, thioredoxine reductase and deiodinases. The deiodinases are selenium dependent enzymes.
Issue: An elderly man with lethargy and tiredness who had normal free T4, TSH and a low T3 with subnormal temperature and low selenium level. Selenium supplementation normalized thyroid function tests.
Lessons learnt: Physicians should have high level of suspicion to identify Se deficiency as an effective replacement will cure the causative disorder.