Blood, immune & lymphNutritional/autoimmuneICD-10 D51
Vitamin B12 deficiency (pernicious anaemia)
Also called: Pernicious anaemia, Megaloblastic anaemia
Lack of vitamin B12 causes anaemia with large red cells and, if untreated, nerve damage. Pernicious anaemia is an autoimmune cause.
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Causes
- Pernicious anaemia (lack of intrinsic factor)
- Vegan diet without supplements
- Gastric or ileal surgery
- Metformin and acid-suppressing drugs long-term
Risk factors
- Older age
- Autoimmune conditions
- Vegan diet
Symptoms
- Tiredness
- Pale or yellowish skin
- Sore red tongue
- Pins and needles
- Memory problems
- Unsteady walking
Diagnosis — tests and examinations
- Full blood count (large red cells)
- Serum B12 and active B12
- Intrinsic factor antibodies
Treatment
Medicines and medical treatment
- Vitamin B12 (hydroxocobalamin) injections, then lifelong maintenance in pernicious anaemia
- Oral B12 for dietary deficiency
Self-care, home remedies and lifestyle
- B12-fortified foods or supplements on a vegan diet
Possible complications
- Subacute combined degeneration of the spinal cord
- Heart failure from severe anaemia
Prevention
- Supplements for vegans and after gastric surgery
Outlook
Anaemia corrects; nerve damage may be permanent if treatment is late.
When to see a doctor
See a doctor for fatigue with tingling or balance problems.
Sources and further reading
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Related conditions
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