Normal Range of Mean Corpuscular Volume (MCV)
The normal reference range for MCV in adults is 80-100 femtoliters (fL). 1
Standard Reference Values
- The established normal MCV range of 80-100 fL applies to all adults regardless of sex 1
- Values below 80 fL indicate microcytic anemia, most commonly caused by iron deficiency 1
- Values above 100 fL indicate macrocytic anemia, most frequently due to vitamin B12 or folate deficiency 1
Clinical Context and Interpretation
When evaluating MCV results, always consider the clinical context rather than relying on the value in isolation:
- MCV should be interpreted alongside red cell distribution width (RDW), as the combination provides superior diagnostic accuracy—a low MCV with elevated RDW (>14%) strongly suggests iron deficiency, while low MCV with normal RDW (≤14%) points toward thalassemia trait 1, 2
- In the presence of inflammation or chronic disease, ferritin levels can be falsely elevated, making transferrin saturation a necessary additional test to confirm iron deficiency when MCV is low 3
- Macrocytosis (MCV >100 fL) warrants evaluation for vitamin B12 and folate deficiency, alcoholism, liver disease, medications (particularly chemotherapy agents), and myelodysplastic syndrome 1
Important Clinical Pitfalls
Do not assume all microcytic anemia represents iron deficiency: Thalassemia, anemia of chronic disease, and sideroblastic anemia require different management approaches and can present with similar MCV values 3
Avoid using MCV as the sole criterion for selecting diagnostic tests: Studies demonstrate that MCV has limited sensitivity (43-48%) for detecting iron deficiency despite high specificity (83-88%), meaning normal MCV does not exclude iron deficiency 4
Remember that MCV can be influenced by multiple concurrent conditions: Iron deficiency can coexist with B12 or folate deficiency, which may normalize an otherwise low MCV, though an elevated RDW often provides a clue to this combined deficiency 3