What Are the Causes for a High MCV Count?
An elevated MCV is most commonly caused by folate and vitamin B12 deficiencies. It can also be caused by chronic alcoholism and become elevated secondary to hemolysis or blood loss, according to the American Academy of Family Physicians.
Normal MCV values lie between 80 and 100 femtoliters. Values above 100 femtoliters are considered elevated and are termed macrocytic. Numbers below 80 femtoliters are also abnormal findings and are termed microcytic, according to MedlinePlus.
Vitamin B12 deficiency is most commonly caused by poor dietary intake and poor absorption. The vitamin is absorbed in the ileum after it is ingested and bound to intrinsic factor, produced by parietal cells in the stomach. Pernicious anemia is a common autoimmune gastritis and causes the destruction of parietal cells, leading to vitamin B12 malabsorpition and deficiency, according to the American Academy of Family Physicians.
Folate deficiency may look like vitamin B12 deficiency on laboratory results. This deficiency is most commonly caused by poor intake, alcoholism, liver disease and certain medications, according to the American Academy of Family Physicians.
One theory that tries to explain the reason for MCV elevation in alcoholics argues that poor intake of folate and vitamin B12 is the primary reason for MCV elevation. Another theory explains that alcohol has a direct toxic effect on the bone marrow, according to the American Academy of Family Physicians.