Mentzer Index: normal range and what it means

Helps distinguish iron-deficiency (>13) from thalassaemia trait (<13).

Normal range

Adult reference range.

  • Thalassaemia trait likely< 13 index
  • Iron deficiency likely≥ 13 index
525 index

What it measures

MCV divided by red cell count, used to tell iron deficiency from thalassaemia trait when the cells are small. Below thirteen points towards thalassaemia, above it towards iron.

What moves it

A calculation used to help distinguish iron deficiency from thalassaemia trait when red cells are small. A screening pointer, not a diagnosis.

How to bring it into range

A screening pointer, not a diagnosis. Confirm with ferritin and, where it matters, haemoglobin electrophoresis.

How fast it responds

It follows the underlying cause.

Also reported as: mentzer

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Common questions

What is a normal Mentzer Index level?
Thalassaemia trait likely: < 13 index. Adult reference range.
What does a high Mentzer Index mean?
A value above the reference band means Mentzer Index is outside the range typical for a healthy adult. A single reading is rarely conclusive on its own — what matters is the trend across draws and the other markers around it, which is why HealthOS reads the whole panel together rather than one number at a time.
How do I improve my Mentzer Index?
A screening pointer, not a diagnosis. Confirm with ferritin and, where it matters, haemoglobin electrophoresis.

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Reference ranges are general-population guidance compiled from common clinical laboratories, not a diagnosis. Lab-to-lab ranges differ. Always read your results with your doctor.