What Is Vitamin Deficiency Anaemia?


Vitamin deficiency anaemia happens when you don't have enough vitamin B12 or B9 (folate) in your body. This type of anaemia occurs because when your body doesn't have enough of these vitamins, it can’t make enough healthy red blood cells. It's more common in people with disorders that make it hard for their bodies to absorb nutrients.1

Instead of creating normal-sized, healthy red blood cells, your body may produce unusually large red blood cells. These enlarged cells are unable to effectively transport oxygen throughout your body as they normally would. Due to the abnormally large size of these red blood cells, vitamin deficiency anaemia is also known as macrocytic or megaloblastic anaemia.

Vitamin B12 or folate deficiency typically arises from insufficient dietary intake or an inability to absorb these vitamins in the digestive system. Pernicious anaemia is a type of vitamin B12 deficiency caused by an autoimmune disorder affecting vitamin B12 absorption. Additionally, folate (folic acid) deficiency can occasionally be a result of medications used in cancer treatment.

Symptoms of vitamin deficiency anaemia 

The symptoms of vitamin deficiency anaemia can vary in severity and may include:

  • Fatigue and weakness - feeling unusually tired and weak, even with adequate rest, is a common symptom of anaemia
  • Pale skin - the skin may appear paler than usual, especially noticeable in the face, palms, and nail beds
  • Shortness of breath - anaemia can mean that your blood can’t carry as much oxygen, causing breathlessness and difficulty breathing, especially during physical activities
  • Dizziness and lightheadedness - insufficient oxygen supply to the brain can result in feelings of dizziness or lightheadedness
  • Heart palpitations - anaemia can lead to an increased heart rate or irregular heartbeat
  • Cold hands and feet - poor circulation due to reduced red blood cell count may cause extremities to feel cold. Nails may become weak and brittle
  • Headache - insufficient oxygen to the brain can result in headaches, especially when standing up or exerting yourself
  • Tingling and numbness - vitamin deficiency anaemia, particularly vitamin B12 deficiency, can cause tingling or numbness in the hands and feet
  • Sore tongue and mouth - some individuals may experience a swollen, red, or sore tongue, along with mouth ulcers1

Causes of vitamin deficiency anaemia

The causes of vitamin deficiency anaemia can be attributed to inadequate intake, poor absorption, or increased demands of vitamin B12 and folate. Some common causes include:

  • Inadequate dietary intake - not consuming enough foods that contain vitamin B12 and folate can lead to a deficiency. This can happen with poor dietary choices, limited access to nutritious foods, or specific dietary restrictions (e.g., vegan or vegetarian diets, as vitamin B12 is mainly found in meat, fish, and dairy)
  • Gastrointestinal disorders - certain medical conditions, such as coeliac disease, inflammatory bowel disease (IBD), and atrophic gastritis, can impair the absorption of vitamin B12 and folate from the digestive tract
  • Pernicious anaemia - this is an autoimmune condition where the body attacks the cells that produce a protein called intrinsic factor, which is essential for vitamin B12 absorption
  • Surgical procedures - some gastrointestinal surgeries, such as gastric bypass or certain bowel resections, can reduce the body's ability to absorb vitamin B12 and folate
  • Medications - certain medications, like proton pump inhibitors (PPIs) used for acid reflux or metformin for diabetes, can interfere with the absorption of vitamin B12
  • Increased demands - during periods of rapid growth (e.g., pregnancy, infancy, or adolescence) or in conditions with increased cell turnover (e.g., certain cancers or haemolytic anaemias), the body may require more vitamin B12 and folate than usual, leading to depletion
  • Alcohol abuse - excessive alcohol consumption can disrupt the absorption and utilisation of vitamin B12 and folate2


Diagnosis of vitamin deficiency anaemia is usually made based on:

Physical examination and medical history

During the initial assessment, your healthcare provider will conduct a physical examination and ask about your medical history. This may include questions about symptoms such as fatigue, weakness, and pale skin, as well as any relevant past medical conditions or surgeries. Additionally, information about dietary habits and family history of anaemia or other relevant conditions will be gathered. This information helps the healthcare provider assess the risk factors and potential causes of the anaemia.

Blood tests

These play a crucial role in diagnosing vitamin deficiency anaemia. Once blood tests indicate the presence of anaemia, further examinations are conducted to identify if the root cause is a deficiency of vitamin B12 or folate. Anaemia associated with vitamin B12 or folate deficiency is suspected when a microscopic analysis of the blood sample reveals abnormally large (macrocytic) red blood cells and multi-lobed (hypersegmented) neutrophils, a type of white blood cell. Additionally, a decrease in the number of white blood cells and platelets may occur, particularly in cases of long-standing vitamin deficiency anaemia.

To confirm the deficiency, the levels of vitamin B12 and folate in the blood are measured, and additional tests may be performed to determine the underlying cause of the vitamin B12 deficiency.

Treatment and management 

The treatment of vitamin deficiency anaemia involves addressing the underlying cause of the deficiency and providing the body with an adequate supply of the deficient vitamins (vitamin B12 and folate). The treatment options may vary depending on the severity of the anaemia and the specific vitamin deficiency involved.

Here are the common approaches to treating vitamin deficiency anaemia:

  • Vitamin supplements - the primary treatment involves oral vitamin supplements to replenish the deficient vitamins. For vitamin B12 deficiency, vitamin B12 supplements are prescribed, and for folate deficiency, folic acid supplements are given. In some cases, vitamin B12 injections may be required, especially for individuals with absorption problems
  • Addressing underlying conditions - if the anaemia is caused by an underlying medical condition that hinders vitamin absorption (e.g., gastrointestinal disorders), treating or managing that condition is essential to improve vitamin absorption and red blood cell production
  • Diet modification - ensuring a balanced diet rich in foods containing vitamin B12 and folate is crucial to maintaining adequate vitamin levels and preventing future deficiencies. Foods such as meat, fish, eggs, dairy products, leafy green vegetables, legumes, and fortified cereals are good sources of these vitamins
  • Lifestyle changes - for individuals with alcohol-related anaemia, reducing or eliminating alcohol consumption can help improve vitamin absorption
  • Regular follow-ups - individuals undergoing treatment for vitamin deficiency anaemia should have regular follow-ups with their healthcare provider to monitor their progress, adjust treatment as needed, and check for any potential side effects of vitamin supplementation

It's essential to consult a healthcare professional for proper diagnosis and treatment recommendations. Early detection and appropriate management can lead to an improvement in symptoms and overall health outcomes for individuals with vitamin deficiency anaemia. Additionally, healthcare providers can offer personalised advice and guidance on diet and lifestyle changes to prevent future deficiencies and promote better well-being.


Prevention of vitamin deficiency anaemia involves adopting healthy habits and ensuring an adequate intake of foods rich in vitamin B12 and folate. Here are some key preventive measures:

  • Balanced diet - maintain a well-balanced diet that includes a variety of foods from all food groups. Incorporate vitamin B12-rich foods such as meat, fish, poultry, eggs, and dairy products. For folate, consume leafy green vegetables (e.g., spinach and kale), legumes (e.g., beans and lentils), and fortified cereals
  • Dietary supplements - for individuals at risk of deficiencies due to dietary restrictions or certain medical conditions, consider taking vitamin supplements as prescribed by a healthcare professional
  • Limit alcohol consumption - excessive alcohol intake can interfere with the absorption and utilisation of vitamin B12 and folate. Moderation or avoiding alcohol can help prevent deficiencies
  • Address underlying health conditions - if you have a medical condition that affects nutrient absorption (e.g., coeliac disease, inflammatory bowel disease), work with your healthcare provider to manage the condition effectively
  • Prenatal care - pregnant people should receive proper prenatal care, including vitamin supplementation, to prevent vitamin deficiency anaemia and support the health of both the mother and the developing foetus
  • Regular health check-ups - periodic health check-ups and blood tests can help identify and address vitamin deficiencies early on, allowing for timely intervention and appropriate treatment
  • Awareness and education - educate yourself and others about the importance of proper nutrition and the role of vitamin B12 and folate in preventing anaemia. This awareness can lead to better dietary choices and healthier lifestyle habits

By implementing these preventive measures, individuals can reduce their risk of developing vitamin deficiency anaemia, and promote their overall well-being. If you have specific health concerns or dietary needs, consult a healthcare professional or a registered dietitian for personalised advice and guidance on preventing deficiencies and maintaining optimal health.


Vitamin deficiency anaemia is a type of anaemia caused by insufficient levels of vitamin B12 or vitamin B9 (folate) in the body. These vitamins are essential for the production of healthy red blood cells, which carry oxygen throughout the body. When there is a deficiency, the red blood cells may become large and ineffective in oxygen transport. 

This condition can result from inadequate dietary intake, poor absorption due to certain medical conditions, or increased demands during growth or specific health conditions. Symptoms of vitamin deficiency anaemia include fatigue, weakness, pale skin, and shortness of breath. Treatment involves vitamin supplementation and addressing the underlying cause, if applicable. Prevention includes maintaining a balanced diet, considering supplements when necessary, and managing health conditions that impact nutrient absorption. Early detection and proper management are crucial for better health outcomes.


  1. Ankar A, Kumar A. Vitamin b12 deficiency. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Jul 28]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK441923/ 
  2. Shipton MJ, Thachil J. Vitamin B12 deficiency – A 21st century perspective. Clin Med (Lond) [Internet]. 2015 Apr [cited 2023 Jul 28];15(2):145–50. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4953733/ 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Leona Issac

Bachelor of Dental Surgery, Rajiv Gandhi University of Health Sciences

Master of Public Health, University of Wolverhampton

Dr Leona Issac is a dynamic professional with a diverse background in dentistry and public health. With extensive experience as a dentist, she offers valuable insights into oral health, complemented by her Master’s degree in Public Health, which provides her with a comprehensive understanding of healthcare systems and their integration with dentistry. Her dedication to public health has led her to actively engage in health promotion, disease prevention and healthcare policy advocacy. Dr Leona continues to make a significant impact on the health and wellbeing of communities through her exceptional work and dedication to her field.

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