INS and diabetes mellitus: A study by Barbara R Cardoso et al. [31] showed a lack of evidence for an association between selenium and diabetes prevalence, but after adjusting for confounders, found that an increase in selenium of 10 μg/L was associated with an increase in insulin of 1.5% (95% CI: 0.4–2.6%) and an increase in HOMA-IR of 1.7% (95% CI: 0.5–2.9%) were associated, i.e., confirming the idea that additional selenium supplementation in populations with high dietary selenium intake is discouraged.