What role does Transferrin play in blood sugar?

Transferrin is an iron-transport protein that carries iron in the blood. It does not directly regulate blood sugar. However, iron status influences glucose metabolism: iron overload (e.g., in hemochromatosis) can impair insulin secretion and increase insulin resistance, while iron deficiency may alter glucose tolerance. Transferrin saturation is used as a marker for iron overload, a risk factor for type 2 diabetes. But transferrin itself does not control blood glucose. The evidence is mechanistic and observational, not causal. Consumer tests measuring transferrin should be interpreted cautiously; they do not diagnose diabetes or prediabetes. A physician should evaluate any abnormalities in iron metabolism.