What role does Ferritin Eisenmangel play in Müdigkeit?

Ferritin is the body's iron storage protein. Low ferritin (iron deficiency) is a well-established cause of fatigue because iron is critical for hemoglobin synthesis and oxygen transport. Without sufficient iron, tissues receive less oxygen, leading to tiredness, poor concentration, and reduced physical performance. However, ferritin is also an acute-phase reactant: inflammation or infection can raise ferritin levels even when iron stores are low. Therefore, low ferritin should be interpreted alongside other markers (e.g., hemoglobin, transferrin saturation, CRP). The evidence linking iron deficiency to fatigue is strong (human-strong), supported by numerous clinical studies and guidelines. Iron supplementation can improve symptoms when deficiency is confirmed, but should only be taken under medical supervision, as excess iron is harmful. Caveat: fatigue has many causes – iron deficiency is just one possibility.