Why measure MCV?
Normal MCV suggests that the production and division of red blood cells are following a normal pattern and procedure. This indirectly implies that all the building blocks and neighboring processes needed for this to properly function are intact. Increasing difficulties maintaining normal MCV is many times seen with increased age, why normal levels are also associated with a younger biological age. By tracking MCV together with other biomarkers, you can monitor your body’s ability to create healthy red blood cells and track the progress of your biological age.
MCV can be helpful in the investigation and diagnosis of various conditions, such as:
B12, folate and iron deficiency
Chronic alcohol abuse
Biological aging (with the Levine clock)
MCV stands for Mean Corpuscular Volume and is a biomarker measuring the average size of red blood cells in a blood sample. MCV is a natural component when testing your “blood status”.
High levels of MCV mean that the size of your red blood cells are larger than normal. This indicates that there is either an affected production, where enlarged red blood cells are produced, or an impaired process of destruction, resulting in an average increase in size. Deficiency in B12 or folate are two more common causes of enlarged red blood cells, since cells grow larger before they divide, when the needed building blocks are lacking. Damage to the bone marrow, seen in many with chronic alcohol abuse, can have the same effect on red blood cell production. In less common cases, liver diseases, interfering with the process of breaking down red blood cells, as well as hypothyroidism and certain medications can cause enlargement and an increased MCV value.
If MCV is increased and Hb is low, this can indicate what is known as macrocytic anemia, meaning low levels of hemoglobin but enlarged red blood cells.
Low levels of MCV mean that the size of your red blood cells are smaller than normal. This indicates that there is an affected production, where smaller red blood cells are produced. One of the more known causes behind the production of small red blood cells is iron deficiency. Red blood cells need hemoglobin to carry oxygen, and hemoglobin depends on iron. Lack of iron will result in the absence of hemoglobin in the red blood cells, thus producing smaller cells. Blood loss will also cause a decreased MCV. This is because the body quickly pushes out somewhat immature red blood cells to compensate for the loss of existing blood, which lowers the average size in circulating blood. There are conditions that interfere with the production of red blood cells such as kidney diseases or inflammatory conditions. These usually come with several other symptoms and deviating test values. In very rare cases, there is a genetic disorder affecting the production of red blood cells, known as Thalassemia. This genetic defect is inherited and is not acquired.
In general, MCV is measured in femtoliters (fL) and the ranges are divided as follows:
Low levels: Below 82 fL
Normal levels: 82-98 fL
High levels: above 98 fL