Ferritin
What It Means
Ferritin reflects stored iron and is also an acute-phase reactant (rises with inflammation).
Why It Matters
Core marker for identifying iron deficiency, iron overload, and hidden inflammation.
Why It Matters
Optimal is typically 40–150 ng/mL. Low = deficiency; high + high CRP = inflammation. Best interpreted with iron, TIBC, and transferrin saturation.