Vitamin B12 deficiency: what is pernicious anemia and why can it be so dangerous?

An estimated 6% of people in the US and UK suffer from a vitamin B12 deficiency. The condition is recognized by the World Health Organization as a global health problem that could impact millions of lives. B12 deficiency is typically characterized by symptoms such as extreme fatigue, lack of energy, muscle weakness and even memory problems. Not only that, but it can also cause a number of serious health problems, such as irreversible nerve damage, anxiety or depression, or disorders that affect coordination, balance and speech.

Although some B12 deficiencies are caused by diet, the most common reason for low B12 levels worldwide is an autoimmune disease called pernicious anemia. This is a chronic form of low B12 that can have serious health consequences if left untreated in the long term. However, because the symptoms of the condition typically resemble other common conditions, it is often misdiagnosed as depression or anxiety. Not only does the condition cause physical suffering, the stigma of living with this chronic condition can also cause serious psychological damage, as I have shown in my research.

Vitamin B12 – also known as cobalamin – is a water-soluble vitamin found in animal by-products, such as meat, fish and dairy. Other sources include fortified cereals, bread and plant-based milk. People who do not regularly consume animal products are at risk of developing a B12 deficiency. To reduce this risk, vegans are recommended to consume at least three micrograms of B12 daily through fortified foods, or by taking a regular B12 supplement.

However, most low B12 levels are caused more by pernicious anemia. The condition makes it difficult for people to process vitamin B12 because the immune system affects the functioning of important parietal cells in the stomach. These cells produce a protein called ‘intrinsic factor’ which is essential for the absorption of vitamins. People with pernicious anemia will produce an antibody against intrinsic factor that destroys any intrinsic factor produced. And so, without any intrinsic factor binding to food, they cannot extract B12. Without B12, the body is unable to produce enough healthy red blood cells. The condition can also be caused by a weakened stomach lining. This can happen because of atrophic gastritis, a chronic inflammation in the stomach that eventually weakens the lining.

A lifelong condition

An estimated five in 100,000 people in Britain have pernicious anaemia. It affects people of all ages and symptoms can start at any time. However, the condition is more common in people over age 60 because older adults are more likely to develop atrophic gastritis, which increases the risk of B12 deficiency. The number of people with the condition worldwide could be higher than estimated. However, it is difficult to reliably estimate levels of B12 deficiency because there is no agreed-upon definition of how low B12 levels must be to be classified as deficient.

New guidelines have been developed to address problems with current diagnostic methods. They state that a patient’s symptoms are the best indicator of a possible deficiency. It also states that if there is inconsistency with the test result and the patient’s reported symptoms, the patient should still be treated with replacement B12 to prevent possible irreversible damage.

B12 deficiency causes a wide range of debilitating neurological and physical symptoms. The most common symptoms of pernicious anemia are fatigue, memory loss and difficulty concentrating. However, the subtle, nonspecific nature of the condition’s early symptoms can make it difficult to properly diagnose people. A study interviewing members of the Pernicious Anemia Society found that almost half had been misdiagnosed. Another 20% had waited two years or more for a correct diagnosis. For many, symptoms were initially attributed to a hectic lifestyle or diagnosed as anxiety or depression.

Low levels of B12 can lead to nerve damage because the vitamin is essential for the production of myelin, which protects nerve cells from damage. Symptoms of low B12 may initially feel like tingling or numbness in the hands and feet, or balance problems. If pernicious anemia is left untreated, the symptoms can become disabling and the nerve damage irreversible. The term “pernicious” was used to describe the condition as it historically led to death.

When vitamin B12 deficiency is caused by a poor diet, it is treated by prescribing B12 tablets or hydroxocobalamin injections. Once the deficiency is corrected, levels can be controlled by changing diet or taking a supplement regularly.

However, treatment is lifelong for people with pernicious anemia. In Britain, many require frequent injections every 8 to 12 weeks to replace the vitamin. Despite this, many people continue to experience debilitating symptoms, or find that their symptoms return before their next scheduled injection, because their treatment has not been sufficient.

When patients expressed concerns about inadequate treatment or requested more frequent injections, our research found that many healthcare professionals responded negatively and even questioned the legitimacy of the patient’s disease. These types of questions can increase psychological problems and affect the quality of life.

Patients with pernicious anemia also expected high health-related stigma. Many people with chronic health conditions fear that their health conditions will cause them to be devalued by the wider society or will be a source of discrimination. Stigma not only affects relationships with healthcare providers, but can also cause an increased incidence of anxiety and depression.

The lack of appropriate guidelines for the diagnosis and treatment of pernicious anemia is problematic and there is an urgent need to review them. It is important that both the general public and health professionals are more aware of the symptoms resulting from inadequate B12 levels so that the condition can be diagnosed before long-term damage occurs.The conversation

Heidi Seage, senior lecturer in psychology, Cardiff Metropolitan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Leave a Reply

Your email address will not be published. Required fields are marked *