Megaloblastic Anaemia: Causes, Symptoms, and How to Treat It

What is megaloblastic anaemia?

Megaloblastic anaemia is a type of macrocytic anaemia characterised by the production of abnormally large, immature red blood cells called megaloblasts. These cells are unable to function properly, leading to a decrease in healthy red blood cells. Megaloblastic anaemia is most often caused by deficiencies in either vitamin B12 (cobalamin) or vitamin B9 (folate).

How does megaloblastic anaemia affect our body?

Megaloblastic anaemia disrupts the body’s oxygen supply by reducing the number of healthy red blood cells, which are essential for transporting oxygen from the lungs to all tissues and organs. This shortage is often due to deficiencies in vitamin B12 or folate, which are vital for red blood cell production. When the body lacks these nutrients, red blood cells become unusually large and misshapen, struggling to function properly. Consequently, the body experiences symptoms like fatigue, muscle weakness, and pale skin due to inadequate oxygenation.

Neurological issues may arise as well, especially with prolonged B12 deficiency, leading to tingling sensations, balance problems, and even memory loss. Additionally, digestive symptoms like a sore tongue and appetite loss may occur. Megaloblastic anaemia can severely affect overall health if left untreated, impacting both physical and mental well-being.

Is megaloblastic anaemia a serious illness?

Yes, megaloblastic anaemia can be a serious condition if left untreated. Vitamin B12 deficiency, in particular, can cause permanent neurological damage if not addressed promptly. Additionally, the systemic effects of anaemia can result in significant morbidity, including an increased risk of heart failure and infections.

How common is megaloblastic anaemia?

While the exact prevalence of megaloblastic anaemia is not well-documented, it is estimated that around 4% of the general population has macrocytosis, a hallmark of this condition. However, only a small fraction of these cases are due to megaloblastic anaemia specifically.

What causes megaloblastic anaemia?

Megaloblastic anaemia causes are primarily attributed to deficiencies in vitamin B12 and vitamin B9 (folate), both essential for red blood cell production. Poor diet, malabsorption, and certain medications can contribute.

What causes vitamin B12 deficiency?

• Vitamin B12 deficiency can stem from several causes, most notably pernicious anaemia, an autoimmune disorder that reduces intrinsic factor production, which is crucial for B12 absorption in the small intestine.
• Without intrinsic factors, even adequate dietary intake fails to meet the body’s needs.
• Malabsorption issues also play a significant role; conditions such as chronic gastritis, Crohn's disease, celiac disease, and certain infections (like tapeworm) can interfere with B12 absorption.
• Individuals who’ve undergone gastric or bowel resection may also face absorption challenges due to reduced surface area in the digestive tract.
• Dietary deficiency, although less common, can affect strict vegans and vegetarians, as natural B12 sources are mainly animal-based. Those not consuming B12-fortified foods or supplements are at higher risk.
• Certain medications, including metformin (used for diabetes) and proton pump inhibitors, may further reduce B12 absorption, increasing deficiency risk over time.

What causes vitamin B9 (folate) deficiency?

Vitamin B9 (folate) deficiency can arise from several factors.

• Dietary insufficiency is a common cause, especially in diets low in green leafy vegetables, fruits, meats, and liver, which are rich in folate.
• Malabsorption disorders like celiac disease, Crohn’s disease, or inflammatory bowel disease can also interfere with folate uptake in the small intestine, leading to deficiency even with adequate dietary intake.
• Increased demand for folate can also contribute to deficiency, as seen in pregnancy and lactation, where the body requires higher folate levels to support foetal development and milk production.
• Certain medical conditions, such as cancer and hemolytic anaemia, can also raise folate requirements.
• Alcoholism is another significant factor; chronic alcohol intake depletes folate stores in the body and impairs its absorption.
• Additionally, certain medications, including anticonvulsants and methotrexate, may interfere with folate metabolism, increasing deficiency risk.

What are the symptoms of megaloblastic anaemia?

Megaloblastic anaemia symptoms can develop gradually and may not be noticeable until the anaemia becomes severe. Common signs and symptoms include:

• Fatigue and weakness
• Pale skin
• Shortness of breath
• Dizziness or lightheadedness
• Rapid or irregular heartbeat
• Glossitis (swollen, red tongue)
• Gastrointestinal issues, like diarrhoea and nausea
• Neurological symptoms (in cases of vitamin B12 deficiency), such as:
  • Numbness and tingling sensations
  • Memory problems
  • Difficulty walking

Megaloblastic anaemia symptoms occur due to impaired red blood cell production, reducing oxygen delivery to tissues and affecting physical and cognitive health.

How to diagnose megaloblastic anaemia?

Megaloblastic anaemia diagnosis involves a combination of clinical evaluation, blood tests, and other diagnostic procedures:

• Complete Blood Count (CBC): This test measures the size, number, and shape of red blood cells. In megaloblastic anaemia, the CBC may show macrocytic anaemia with large, oval-shaped red blood cells.
• Vitamin B12 and Folate Levels: Blood tests can determine the levels of these vitamins in the body, helping to identify the underlying cause of the anaemia.
• Peripheral Blood Smear: A sample of blood is examined under a microscope to look for abnormal red blood cells characteristic of megaloblastic anaemia.
• Additional Tests: Depending on the suspected cause, further tests like the Schilling test (to assess vitamin B12 absorption) or tests for underlying conditions may be performed.

How to treat megaloblastic anaemia?

Megaloblastic anaemia treatment focuses on addressing the underlying cause, which is typically a vitamin B12 or folate deficiency.

• Vitamin Supplementation:
  • For vitamin B12 deficiency, intramuscular injections are often used initially, especially in cases with severe neurological symptoms. Oral supplements may be used for maintenance.
  • Folate deficiency is treated with oral folate supplements.
  • It's crucial to rule out vitamin B12 deficiency before treating with folate alone, as this can mask B12 deficiency and allow neurological complications to progress.
• Dietary Modifications: Increasing the intake of vitamin B12 and folate-rich foods, such as meat, poultry, fish, eggs, dairy products, leafy greens, and fortified grains, can help prevent and manage the condition.
• Treating Underlying Conditions: If an underlying medical condition is causing the vitamin deficiency, treating that condition is essential for long-term management.
• Lifelong Supplementation: In some cases, such as pernicious anaemia, lifelong vitamin B12 supplementation may be necessary.

How can we reduce our risk of developing megaloblastic anaemia?

To lower the risk of megaloblastic anaemia, it's essential to consume enough vitamin B12 and folate (vitamin B9) through a balanced diet.

Foods rich in vitamin B12 include:

• Meat, poultry, and fish
• Eggs
• Dairy products
• Fortified cereals and plant-based milks

Foods high in vitamin B9 (folate) include:

• Leafy green vegetables (spinach, kale, collard greens)
• Fruits (citrus, berries, avocado)
• Legumes (beans, lentils, peas)
• Nuts and seeds
• Fortified grains and cereals

Those on a vegan or strict vegetarian diet may benefit from a B12 supplement, as plant-based sources are limited. Ensuring sufficient intake of these vitamins helps maintain healthy red blood cells and lowers the risk of deficiency.

What can we expect if we have megaloblastic anaemia?

If you are diagnosed with megaloblastic anaemia, your healthcare provider will work with you to develop a personalised treatment plan based on the underlying cause and the severity of your condition. With proper megaloblastic anaemia treatment, most individuals can expect a significant improvement in their symptoms and overall health. However, it is crucial to follow your treatment plan diligently and attend regular check-ups to monitor your progress and prevent complications.

Foods with Vitamin B12

Vitamin B12 is essential for red blood cell production and neurological health. Foods rich in B12 mainly come from animal sources, including:

• Meat, poultry, and fish: Beef, chicken, salmon, and tuna are all excellent sources.
• Eggs and dairy products: Milk, cheese, and yogurt provide B12, making them ideal for daily intake.
• Fortified cereals and plant-based milks: For vegetarians and vegans, many cereals and non-dairy milks like soy and almond are fortified with B12.

Foods with Vitamin B9 (Folate)

Vitamin B9, or folate, is crucial for DNA synthesis and cell growth. Key folate-rich foods include:

• Leafy greens: Spinach, kale, and collard greens are top sources.
• Fruits: Citrus fruits, avocados, and berries contain good folate levels.
• Legumes: Beans, lentils, and peas are nutrient-dense in folate.
• Fortified grains: Many breads and cereals are enriched with folate for added benefits.

Conclusion

Megaloblastic anaemia is a serious condition that can significantly impact your health and quality of life. If you suspect you may have megaloblastic anaemia symptoms, don't hesitate to consult with your healthcare provider for personalised advice and treatment.

At Metropolis Healthcare, we offer comprehensive diagnostic services, including blood tests for vitamin B12 and folate levels, to help identify and manage conditions like megaloblastic anaemia. Our team of skilled phlebotomists can perform convenient at-home sample collections, ensuring a comfortable and hassle-free experience. With our state-of-the-art laboratories and commitment to delivering accurate, reliable results, you can trust Metropolis Healthcare to be your partner in prioritising your health and well-being.