What are the causes of high mcv count?

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MCV stands for mean corpuscular volume. It is the size measurement of the average RBC, red blood cell. Macrocytic is enlarged RBCs. A decreased MCV is microcytic. Testing the MCV count is part of a complete blood count or CBC. Blood tests are routine and used during physicals and diagnosing certain conditions.

MCV counts are important when looking for anaemia.

Alcoholism or Aplastic Anemia

Macrocytosis is the condition of excess large RBCs and can cause chronic liver disease. The normal MCV value is 80 to 95fl for both sexes. MCV that is 100 to 105fl/cell or more can be the result of chronic alcoholism when not showing a deficiency in folate.

Other conditions that can cause macrocytosis are aplastic anaemia, a condition caused from the lack of red blood production, and spleenectomy, the removal of the spleen.

Nonmegablastic macrocytosis is another condition related to the size of red blood cells. The red blood cells are enlarged but the condition is not caused from B12 or folic acid deficiencies. Testing for this condition consists of examining slides from bone marrow to rule out myelodysplasia an advanced liver disease.

B12 Deficiency

Vitamin B12 deficiency can cause macrocytosis, which is present in pernicious anaemia. The vitamin can be found in meat, fish and dairy products. The deficiency is caused by a lack of absorption of the vitamin in the digestive tract. The deficiency is found in older adults who have insufficient hydrochloric acid. It can also be found in people who have coeliac and Crohn's disease, pernicious anaemia, gastrointestinal surgery patients and vegetarians.

Folate Deficiency

A deficiency in folate, or folic acid, can occur when there is a lack of red blood cells,causing macrocytosis. Folate is present in green leafy vegetables and liver. It is not stored by the body and needs replenishment from a balanced diet.

Folate deficiency can also be the result of alcoholism, certain medications like Dilantin and barbiturates, coeliac and crohn's disease and gastrointestinal surgery.

Symptoms and Treatment

People who suffer from macrocytosis anaemia will experience fatigue, a sour mouth or tongue, headache, pallor, numbness and tingling, muscle dysfunction and dementia.

Treatment includes vitamin supplements of B12 and folic acid. Medications causing the condition may be eliminated.


Folate deficiency in pregnant women can cause spina bifida in newborns, a condition where the spinal cord has failed to close properly. The condition can cause paralysis and brain dysfunction.

Other complications that are consistent with both B12 and folate deficiencies include curly grey hair, infertility, increased pigment in the skin, and heart failure in people with heart disease.