Type 2 Diabetes. Some news reports have suggested that high selenium intakes and status may be potential risk factors for the development of type 2 Diabetes mellitus. However, current data show that supplemental selenium does not cause diabetes [Schomburg 2020].
Two large randomized controlled trials using selenium supplements have shown no diabetes risk caused by 1) a selenomethionine product [Lippman 2009] and 2) a selenium-enriched yeast product [Thompson 2016; Jacobs 2019]. In neither study was there any significant risk of diabetes at the recommended dosage, not even among selenium-replete individuals of various ages and both genders [Schomburg 2020].
Moreover, in the Selenium Trial, the researchers saw no causal role for selenium in the development of insulin resistance or diabetes. Instead, they observed decreased fasting blood glucose levels in the selenium supplemented group compared to the control group [Jacobs 2019].