Pernicious B12 Anemia

Anemia is a reduction in the oxygen carrying capacity of the blood, and multiple factors can cause this. Red blood cells carry oxygen to every tiny corner of your body – and a loss of blood, a decrease in the production of red blood cells, abnormal red cell form or function can all cause an Anemia. The question is: What does vitamin B12 have to do with that?

Vitamin B12 Anemia

This vitamin is involved in the production of your red blood cells. I could tell you the steps involved in red blood cell production but I’m a little scared you might not share my crazy passion for medicine so I’ll refrain from stating the boring details. In a nutshell, without vitamin B12, red blood cells cannot be produced normally. Even though their number does not increase or decrease as such in the blood, their shape is what mainly changes when a vitamin B12 deficiency occurs.

Vitamin B12 anaemia is grouped under a type of anaemia known as ‘Megaloblastic Anaemia’ due to the characteristic shape of the red blood cells. They turn into large abnormal looking cells which do not resemble their disc-shaped normal counterparts at all. They are large and immature, thus the name ‘megaloblasts’ – meaning large and immature.

Folic acid deficiency has very similar effects on red blood cells and is the other type of megaloblastic anaemia currently known. In addition, a type of white blood cells called ‘neutrophils’ are also seen to have a similarly abnormal shape along with exhibiting more lobes within their nuclei as compared to their normal counterparts.

Enough with the boring details, let’s examine the more interesting part.

Signs and Symptoms of a B12 Anemia

So what do all these abnormally shaped red blood cells do? As a matter of fact, the symptoms of B12 anemia are pretty much the same as any other type of anemia because the basic problem is the same – your tissues aren’t getting enough oxygen. However, a person might have other symptoms related to the cause of the deficiency such as neurological issues (seen with B12 anaemia), etc. The signs and symptoms seen only due to the anemia of B12 deficiency are:

  • Lethargy
  • Tiredness
  • Pallor
  • Heart palpitations
  • Light-headedness
  • Shortness of breath
  • Drowsiness
  • Decreased energy

In addition, B12 deficiency causes symptoms such as numbness, tingling, balancing problems, confusion, memory loss, diarrhoea, etc. More details regarding the symptoms of B12 deficiency can be found here.

What is Pernicious Anemia?

Pernicious anemia (also called Biermer’s anemia, Addison’s anemia, or Addison–Biermer anemia) is a type of anemia which results due to an auto-immune process that attacks particular cells of the stomach which are responsible for helping in B12 absorption. These cells produce a substance called intrinsic factor without which B12 cannot be absorbed in your intestines.

An auto-immune process occurs when your own immune system starts attacking particular cells of your body falsely perceiving them as foreign. The reason as to why that happens is massively discussed and researched on within the medical community but we are still not exactly sure as to what the cause is. Genetics, infections, environmental causes, race and numerous factors have been hypothesized and proven to be the contributing factors but how they do that still needs to be researched upon further.

Simply said, pernicious anemia is an auto-immune process that attacks those cells of your stomach without which you cannot effectively absorb vitamin B12 from your gut. It’s a cause of B12 deficiency and is associated with other auto-immune conditions such as Addison’s disease, Thyroiditis, etc. Here are the symptoms of Pernicious Anemia.

Therefore, people who have this form of B12 anaemia will need B12 supplementation via the intramuscular or intravenous route (such as B-12 injections) for as long as they live and might have symptoms of other auto-immune conditions associated with this disease.

Other Causes of B12 Anemia

  • Stomach surgery
  • Ulcers or cancer of the stomach

The stomach produces intrinsic factor which is necessary for B12 absorption.

  • Consuming little or no B12

Vegans and vegetarians are at an increased risk.

  • Surgery of the small intestine

The small intestine absorbs vitamin B12, therefore a decrease in its length can cause B12 deficiency.

  • Diseases of the small intestine

Crohn’s disease, ulcerative colitis, celiac disease, etc.

  • Infestation with the fish tapeworm
  • Old age

One of the reasons for old people being at a greater risk of developing B12 deficiency is that with age, the lining of the stomach ‘wears off’ and thus intrinsic factor producing cells decrease.

  • Certain medications (such as metformin, etc).

How is B12 Deficiency Anemia Diagnosed?

A history and physical examination are the key to making a differential diagnoses by doctors. These can be narrowed down and the final diagnoses can be reached by ordering the right tests. In case of B12 deficiency anaemia, blood tests are required. Urine testing can also be done. Another test, known as the Schilling test, is done to find out the particular cause of B12 deficiency. For more details, please refer to the information given here.

Important: Is B12 Deficiency And Its Symptoms Reversible?

Vitamin B12 Deficiency is reversible with supplementation which can be done via pills, injections, patches, etc. The dosage and frequency depends on the cause, the severity of the deficiency, etc. However, what you should know is that some very serious symptoms of B12 deficiency are NOT reversible.

Since B12 is involved in the formation of the protective myelin sheath which surrounds your nerves, its deficiency causes problems in the nervous system (such as pins and needles sensations, confusion, depression, loss of balance, tremors, etc). When the damage to your nervous system reaches a certain point, it will be impossible to get it back to normal.

With continued deficiency of B12, nervous system damage could reach a point where a person could become paralyzed and permanently disabled. Therefore, don’t think that this deficiency is reversible and you can get back to normal by mere supplementation. Things won’t be looking that positive when you’ve been deficient for too long.

So yes, the deficiency is usually reversible, except for its most serious symptoms which show up when you’ve been deficient for too long.

Written by Dr. Aqsa Ghazanfar, main author of ‘The B12 Deficiency Survival Handbook’.