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Vitamin Deficiency Anemia

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Folate, vitamin B6, vitamin B12 and vitamin C are the vitamins needed for a body to produce healthy RBCs. Deficiency in one or more of these vitamins may cause anemia. Among these, the commonest type is megaloblastic anemia (MA) caused by deficiencies in vitamin B12 and folic acid.

Dietary vitamin B12 deficiency usually results from inadequate absorption but deficiency can develop in vegans who do not take vitamin supplements. Other than megaloblastic anemia , vitamin B12 deficiency also causes damage to the white matter of the spinal cord and brain, and peripheral neuropathy.


This type of anemia is characterized by many large immature and dysfunctional RBCs (megaloblasts) in the bone marrow, and also by hypersegmented or multisegmented neutrophils. Symptoms of megaloblastic anemia develop slowly and are similar to symptoms produced by other types of anemia. Neurologic symptoms such as mild-to-moderate weakness and neural pain may develop independently from and often without hematologic abnormalities.

Pernicious anemia

Other than inadequate nutritional intake, vitamin B12 deficiency may also result from lack of intrinsic factor in gastric (stomach) secretions, which is necessary for gastrointestinal absorption of vitamin B12. This type of anemia in which a lack of intrinsic factor occurs is called pernicious anemia.

Other types of megaloblastic anemia may be associated with type 1 diabetes, thyroid disease, leukemia and a family history of the disease.



In addition to a complete medical history and physical examination, diagnostic procedures for megaloblastic anemia may include blood tests such as CBC, serum B12, serum folate, bone marrow examination and additional investigation such as the Schilling test. The Schilling test is useful in diagnosing intrinsic factor deficiency, as in classic pernicious anemia.


The treatment of megaloblastic anemia consists of replacement of the deficient vitamin. Oral vitamin B12 in the dosage of 1000–2000 μg (1–2 mg) can be given on daily basis to patients who do not have severe deficiency or neurologic manifestations. For more severe deficiency, vitamin B12 is commonly administered by injection. Initially intramuscular injection of vitamin B12 1 mg is usually given daily or weekly for several weeks until the blood levels of vitamin B12 return to normal. Subsequently, the injections are given once a month. Folic acid can be taken as, one tablet daily in the dosage of 0.5–1 mg. Vitamin B12 treatment must be continued lifelong unless the causative mechanism for the deficiency is corrected.

Related articles:

Iron deficiency anemia

Anemia of chronic disease

Anemia in pregnancy

Written by: Healthplus24 team
Date last updated: July 03, 2011