Evidence check: Ferritin Eisenmangel in the context of blood sugar

The relationship between ferritin (iron stores) and blood sugar is complex. Ferritin is an acute-phase reactant: low levels indicate iron deficiency, but high levels can also result from inflammation (e.g., in metabolic syndrome). Some studies suggest that iron deficiency may impair insulin sensitivity because iron is required for mitochondrial function and enzymes involved in glucose metabolism. However, the evidence is inconsistent: some research finds no clear link, while others report an association between low ferritin and impaired glucose tolerance. Additionally, iron deficiency can cause fatigue and reduced physical activity, indirectly affecting blood sugar. Importantly, ferritin alone is insufficient to assess iron status; transferrin saturation and CRP should be measured. The provided context does not contain direct studies on ferritin and blood sugar. Therefore, this assessment is based on general medical knowledge. Evidence grade: mixed/unclear. Clinically, if blood sugar is unexplained and iron deficiency is suspected, further diagnostic workup is warranted.