Is Ferritin Included on a CBC or CMP?
No, ferritin is not included on either a Complete Blood Count (CBC) or Comprehensive Metabolic Panel (CMP) and must be ordered as a separate test.
What These Standard Panels Actually Include
Complete Blood Count (CBC)
A CBC assesses bone marrow function and includes 1:
- White blood cells
- Hemoglobin
- Platelets
- Red blood cell indices (mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration)
- Red blood cell distribution width
- Hematocrit
Ferritin is explicitly not part of the CBC 1. While the CBC can suggest iron deficiency through findings like low mean corpuscular volume or elevated red blood cell distribution width, it cannot directly measure iron stores 1.
Comprehensive Metabolic Panel (CMP)
The CMP is a chemistry panel that evaluates metabolic function and includes electrolytes, glucose, kidney function tests (creatinine, urea), and liver function tests 1. Ferritin is not included in this panel.
Why Ferritin Requires Separate Ordering
Ferritin is a specialized iron storage protein marker that requires its own specific assay 1. Multiple guidelines consistently emphasize that ferritin must be ordered separately as part of an iron panel or anemia workup 1.
What Constitutes a Complete Iron Panel
When evaluating iron status, the minimum workup should include 1:
- Serum ferritin (the most specific indicator of iron stores)
- Transferrin saturation
- Serum iron concentration
- Total iron-binding capacity (TIBC)
- Complete blood count with red cell indices
- C-reactive protein (to assess for inflammation)
Clinical Implications
The cost and unavailability of clinic-based ferritin measurement methods are recognized barriers to its use in screening 1. This is why some clinicians may rely solely on CBC parameters, but this approach has significant limitations 2, 3.
Diagnostic Performance
- Ferritin is the most specific indicator available for depleted iron stores 1
- At a threshold of 30 µg/L, ferritin has 79% sensitivity and 98% specificity for iron deficiency in non-healthy adults 4
- Serum iron and TIBC alone provide no additional diagnostic information if ferritin is available 3
- Ferritin outperforms all other biomarkers in predicting bone marrow iron stores 5
Important Caveats
Ferritin is an acute-phase reactant, meaning inflammation, infection, or tissue damage can falsely elevate levels and mask iron deficiency 1, 6. In the presence of inflammation 1:
- Without inflammation: ferritin <30 µg/L indicates iron deficiency
- With inflammation: ferritin up to 100 µg/L may still represent iron deficiency
- Ferritin >100 µg/L with transferrin saturation <20% suggests anemia of chronic disease
Bottom line: Always order ferritin as a separate test when evaluating iron status—it is not automatically included in routine laboratory panels 1.