How is macrocytosis treated?

For mild cases of macrocytosis, no treatment may be required. The treatment of macrocytosis depends on its cause. For cases directly linked to vitamin B12 deficiency, injections of the vitamin can be given. For mild cases, oral supplements may be prescribed, along with a balanced diet. For cases in which macrocytosis is related to another condition, such as celiac disease or Crohn’s disease, vitamin B12 injections can be given until the underlying cause of the deficiency has been treated. In some cases, it may be necessary to take vitamin B12 injections on a long-term basis.

What are the potential complications of macrocytosis?

Mild macrocytosis is unlikely to lead to complications. If severe macrocytosis is left untreated for periods longer than six months, however, neurological complications due to low oxygen levels in the body can develop. Individuals with macrocytosis due to pernicious anemia have an increased risk of developing stomach polyps (benign growths) and stomach cancer.

Getting prompt medical treatment can prevent the development of permanent neurological complications of macrocytosis. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you.

Long-term neurological complications of macrocytosis include:

  • Dementia
  • Depression
  • Nerve problems that cause pain, numbness or tingling
  • Problems with balance or coordination


  1. Megaloblastic anemia. Medline Plus, a service of the National Library of Medicine National Institutes of Health.
  2. Anemia - B12 deficiency. Medline Plus, a service of the National Library of Medicine National Institutes of Health.

What is macrocytosis?

Macrocytosis, or megaloblastic anemia, is a blood condition characterized by insufficient and unusually large red blood cells. The lack of viable red blood cells leads to oxygen deficiency throughout the body. Over time, this lack of oxygen can cause symptoms related to many organ systems.

Symptoms of macrocytosis can range from very mild to severe. General symptoms of macrocytosi... Read more about macrocytosisintroduction


What are the symptoms of macrocytosis?

Mild macrocytosis produces no symptoms. Symptoms of moderate macrocytosis include fatigue and weakness, problems with digestion, and neurological symptoms. Neurological symptoms, such as confusion, depression, or numbness, may indicate nerve dama... Read more about macrocytosissymptoms


What causes macrocytosis?

Usually, macrocytosis is caused by nutritional deficiency, specifically of folate or vitamin B12. This can arise from a hereditary condition called pernicious anemia, in which a protein called intrinsic factor is lacking in your gut. Intrinsic factor helps your body absorb vitamin B12. Vitamin B12 is essential for replenishing folate, which is required by your body to make red blood cells.
Read more about macrocytosiscauses

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Heart, Blood and Circulation