Pernicious Anemia

Pernicious anemia used to be a fatal disease, before scientists discovered a way of treating it with cobalamin, or vitamin B12. Today, doctors recognize the early signs of pernicious anemia-vitamin B12 deficiency (abnormally low levels of vitamin B12 in the blood), in symptoms such as fatigue, chronic pain, memory problems, and disorientation. Though it’s no longer considered a fatal illness, long-term pernicious anemia still continues to cause severe, irreversible neurological damage for many sufferers.

Pernicious anemia and vitamin B12

Vitamin B12 is essential for maintaining normal, healthy red blood cells. With pernicious anemia (megaloblastic anemia), red blood cells develop as abnormally large, distorted shapes that your body can’t use to distribute oxygen. This occurs when vitamin B12 levels are too low to support DNA synthesis, resulting in a gradual depletion of red blood cells and, more importantly, oxygen throughout your body. Lack of the intrinsic factor enzyme, a necessary digestive protein for absorbing vitamin B12 from food, is usually the cause of vitamin B12 deficiency.

In addition to supporting red blood cell production, vitamin B12 is also crucial for protecting your nervous system. Myelin, a fatty coating which insulates your nerve cells and enhances communication, is directly dependent on healthy levels of vitamin B12. Understandably, pernicious anemia results in an erosion of myelin (demyelination.) Nervous reflexes become slow, and you develop neurological syndromes such as painful neuralgia and mobility disorders. Untreated, pernicious anemia can result in irreversible nerve cell damage and destruction.

Pernicious anemia symptoms

Some of the symptoms associated with pernicious anemia include:

  • Chronic fatigue
  • Depression
  • Anxiety
  • Paranoia
  • Short-term memory loss
  • “Brain fog” (disorientation)
  • Painful tingling in the hands and feet (“pins and needles”)
  • Frequent numbness, or temporary paralysis


Who’s at risk?

Most often, pernicious anemia results from an autoimmune disorder which inhibits absorption of vitamin B12. However, not all people diagnosed with pernicious anemia acquired it genetically.

Risk factors for pernicious anemia include:

  • Autoimmune disorders
  • Old age
  • Gastrointestinal illnesses
  • Chronic pain disorder
  • Bariatric surgery
  • Ileostomy
  • Diabetes
  • Alcoholism



Treatment for pernicious anemia consists of regimented doses of vitamin B12, usually in the form of vitamin B12 injections or sublingual vitamin B12 tablets. Patients of pernicious anemia often benefit from taking extra over-the-counter (OTC) vitamin B12 supplements, in addition to the injections.