Ferritin Blood Test: The Most Accurate Iron Test (When Inflammation Doesn't Interfere)
Iron deficiency is the most common nutritional deficiency worldwide, affecting nearly 2 billion people. But iron testing is surprisingly complex because iron exists in multiple forms throughout the body, and each test captures different aspects of iron metabolism. Ferritin has emerged as the best single marker for iron stores, but it's also an acute-phase protein that rises during inflammation, infection, or chronic disease. This dual nature means ferritin can appear normal or even elevated in people who are actually iron deficient, leading to missed diagnoses and delayed treatment.