Recently, I did a search of the Medline database on the subject of selenium supplementation and its effect or non-effect on glucose metabolism, insulin resistance, glycemic control, etc. I limited my search to reports of data from randomized, controlled trials.
Altogether, the Medline search yielded 48 hits. Reading through the abstracts of the 48 journal articles, I was able to eliminate 30 references from consideration. These 30 eliminated studies were studies that included all of my search terms but did not actually measure the effect of an intervention with selenium on some aspect of glucose metabolism.
18 good selenium supplementation studies
I was left with 18 good intervention studies that met my search criteria. I read these studies and separated them into three distinct categories related to the effect of selenium supplementation on glucose metabolism and insulin sensitivity: