Do you suffer from chronic vitamin B12 deficiency? Has anyone in your family been diagnosed with pernicious anaemia? Are you taking oral vitamin B12 supplements to no avail? The nature, symptoms, diagnosis and treatment of pernicious anaemia is discussed below.

Pernicious anaemia is a rare autoimmune disease which arises due to inflammation in the stomach and the inability to absorb vitamin B12 in the small intestine. The cause of pernicious anaemia can also be genetic.

In a healthy person, a protein known as Intrinsic Factor is produced in the stomach. The role of Intrinsic Factor is to extract vitamin B12 from food. The most common vitamin B12 food sources are derived from animals and include milk, cheese, fish, eggs, shellfish and meat.

People with pernicious anaemia produce Intrinsic Factor Antibodies. Hence, these antibodies attack Intrinsic Factor and render it useless. As there is no functioning Intrinsic Factor, vitamin B12 is unable to be absorbed. This is of detriment to the human body as vitamin B12 is one of the three necessary ingredients for healthy, functioning blood cells. Normally, healthy red blood cells are circular and have a concave centre so without vitamin B12, the cells become irregular and may enlarge (also known as megaloblasts). Possible symptoms that may follow include:

·       Nausea and vomiting

·       Confusion and/or memory loss

·       Constipation

·       Loss of appetite

·       Heartburn

·       Fatigue and lethargy

·       Headaches

·       Chest pain

·       Muscle weakness

Numerous tests are needed to diagnose pernicious anaemia, such as:

1. Complete blood count- screens for anaemia by looking at hemoglobin and hematocrit levels

2. Vitamin B12 levels- a lower than normal level indicates a deficiency

3. Intrinsic factor and parietal cell antibodies- identifies antibodies against intrinsic factor and the stomach’s parietal cells

Once a diagnosis of pernicious anaemia has been made, replacement therapy B12 will be needed for life, preferably in a form that by-passes the stomach. This involves vitamin B12 injections that will be administered according to individual vitamin B12 status (usually weekly or monthly). This differs to vitamin B12 deficiency anaemia where the body can absorb vitamin B12, so oral vitamin B12 supplements and diet adjustments may suffice.

Many people with pernicious anaemia require long term management which can prevent damage to different body systems. Please talk to your doctor if you are aware of a genetic link to pernicious anaemia or if you are experiencing any of the above listed symptoms.

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Further Reading:‍

- What is Pernicious Anaemia:

https://pernicious-anaemia-society.org/b12deficiencyandperniciousanaemia/

-Pernicious Anaemia: Symptoms, Causes, Treatment, and More:

https://ahoy-stage.healthline.com/health/pernicious-anemia

Written by 
Mary-Anne Chamoun
Mary-Anne is an Accredited Practising Dietitian and Accredited Nutritionist who has been working in a clinical setting since 2007. She has a particular interest in managing diabetes, malnutrition, IBS, inflammatory bowel disease, and weight loss.