Mean Corpuscular Volume (MCV)

What Is It?

Mean corpuscular volume is a measurement of the average size of red blood cells. The test is a useful marker for the differential diagnosis of anaemia and can also indicate dysfunction associated with bone marrow.[1]

Which tests include this marker?

What Role Does It Play in The Body?

The mean corpuscular/cell volume is a useful assessment tool for underlying anaemia. The test can be used in conjunction with other measurements including mean corpuscular haemoglobin concentration and mean corpuscular haemoglobin. All these measurements were first introduced in 1929 by Wintrobe to help to define the size of red blood cells.[2]

Anaemias can be classified according to the size of the cell i.e.:

  • Normocytic anaemia - normal MCV
  • Macrocytic anaemia - increased MCV
  • Microcytic anaemia - decreased MCV

In conjunction with the other red cell indices and symptoms a diagnosis can be made.[2]

How Does MCV Affect My Wellbeing?

High MCV is an indicator of macrocytic anaemia and is relatively common. There are various causes associated with the development of macrocytic anaemia, including:

  • Nutrient deficiencies (vitamin B12 and folic acid)
  • Alcoholism
  • Medications
  • Bone marrow disease
  • Haemolysis (destruction of red blood cells)[3]

Vitamin B12 deficiency is a relatively common condition which can be serious. The condition can lead to an increased MCV. The western diet contains around 5-30µg of vitamin B12 per day with up to 1.5µg being absorbed. Our body storage is relatively high, so depletion occurs over a period of several years so it can take this long for the condition to manifest. The symptoms of vitamin B12 deficiency can include:

  • Tiredness
  • Weakness

Neurological disturbances with high MCV[4]

Low MCV can indicate microcytic anaemia with a common cause being iron deficiency anaemia. The usual cause for iron deficiency is a lack of iron and symptoms can include:

  • Tiredness
  • Lack of energy
  • Pale skin
  • Heart palpitations
  • Shortness of breath
  • Headaches
  • Sore tongue 

How Can I Improve My Result?

Your diet can help to keep anaemia at bay. Eating a healthy and balanced diet and ensuring you get all of the nutrients you need will help to keep your MCV level normal.


If your MCV level is low there is a good chance your iron level is low too. Good sources of dietary iron include:

  • Red meat – beef, lamb and pork
  • Fish
  • Poultry
  • Dark green leafy vegetables – spinach, cabbage and broccoli
  • Nuts
  • Seeds
  • Pulses[5]

Plant-based sources of iron such as dark green leafy vegetables, nuts, seed, pulses and fortified cereals may be absorbed better in the presence of vitamin C.[6] Try eating fortified breakfast cereals alongside a glass of orange juice or swap chips for a jacket potato with a side of green leafy veg – be sure to eat the skin of the potato.

You should also refrain from drinking tea with your meals as this can affect iron absorption. Instead, you should drink it between meals to ensure you absorb iron effectively.[7]
You also need to make sure your vitamin B12 levels are adequate too. However, you should avoid eating too much as this can have adverse effects and could contribute to a high MCV. Good sources of vitamin B12 include:

  • Meat
  • Fish
  • Dairy products

As vitamin B12 is found only in animal products, vegetarians and vegans can find themselves at risk of becoming deficient. Therefore, these groups may need to consider supplementation.


Exercise is an important aspect of a healthy lifestyle. Regular exercise can help to increase blood flow to muscles which enables oxygen to reach the tissues. Exercise also helps to increase the oxygen carrying capacity of red blood cells.[8]

Both too much and too little iron can influence energy levels and could affect your ability to exercise. Low iron can also influence how well and quickly your muscles repair themselves after exercise.[9] Iron deficiency anaemia may also be more common in athletic groups and may need iron supplementation.

Tests that include this marker

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[1] Hsieh, Y, P., Chang, C, C., Kor, C, T., Yang, Y., Wen, Y, K and Chiu, P, F. (2017). Mean Corpuscular Volume and Mortality in Patients with CKD. Clinical Journal of the American Society of Nephrology: 12(2), pp 237-244.

[2] Sarma, P, R. Red Cell Indices. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 152. Available from:

[3] Stouten, K., Riedl, J, A., Droogendijk, J., Castel, R., van Rosmalen, J., van Houten, R, J., Berendes, P., Sonneveld, P and Levin, M, D. (2016). Prevalence of Potential Underlying Aetiology of Mcrocytic Anaemia in Dutch General Practice. BMC Family Practice: 17.

[4] Hunt, A., Harrington, D and Robinson, S. (2014). Vitamin B12 Deficiency. BMJ: 349(G5226).

[5] British Dietetic Association. (2017). Food Fact Sheet: Iron. Available at:

[6] Lane, D, J, R and Richardson, D, R. (2014). The Active Role of Vitamin C in Mammalian Iron Metabolism: Much More than Just Enhanced Iron Absorption. Free Radical Biology and Medicine: 75, pp 69-83.

[7] Zijp, I, M., Korver, O and Tijburg, L, B, M. (2000). Effect of Tea and Other Dietary Factors on Iron Absorption. Critical Reviews in Food Science and Nutrition: 40(5), pp 371-398.

[8] Mairbäurl, H. (2013). Red Blood ells in Sports: Effects of Exercise and Training on Oxygen Supply by Red Blood Cells. Frontiers in Physiology: 4.

[9] Beard, J and Tobin, B. (2000). Iron Status and Exercise. The American Journal of Clinical Nutrition: 72(2), pp 594S-597S. 

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