All lab markers

Blood count

MCV

Average red-cell size. Small cells point at iron; large cells at B12 or folate. Lower results are the ones to watch.

In more detail

Low = iron-restricted cells; high = B12/folate shortfall.

What commonly moves it

  • Iron deficiencyLow stores or poor delivery limit red-cell production and thyroid conversion.
  • B12
  • Folate

These are commonly described physiological relationships, shared for education. They are not a diagnosis and cannot account for your medications, history, or symptoms — discuss your results with a licensed clinician.

Watching MCV over time?

Dose Compass charts each draw, flags meaningful moves, and helps you prepare questions for your clinician.

Start tracking