clinical features of vitamin B12 deficiency

Last edited 05/2022 and last reviewed 09/2022

• Blood
• macrocytic anaemia - anaemia, jaundice
• neutropenia - infection
• thrombocytopenia - bleeding
• Skin
• angular cheilosis - sore mouth
• glossitis - beefy red tongue
• pigmentation, alopecia
• Gut
• epithelial abnormalities - anorexia, weight loss
• stomach + small bowel - altered bowel habit, malabsorption
• GUS
• epithelial abnormalities - infertility
• CNS
• mental abnormalities - dementia
• peripheral neuropathy, subacute combined degeneration of the cord - paraesthesia, numbness, difficulty in walking, weakness
• Eyes
• retrobulbar neuritis - poor vision
• optic atrophy - blindness
• Other – splenomegaly, fever

Reference:

• (1) Rodriguez NM, Shackelford K. Pernicious Anemia. [Updated 2021 Jul 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK540989/ (accessed 13/05/2022).
• (2) NHS. Vitamin B12 or folate deficiency anaemia. Available from: https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/ (accessed 13/05/2022).
• (3) Langan RC, Goodbred AJ. Vitamin B12 Deficiency: Recognition and Management. Am Fam Physician. 2017 Sep 15;96(6):384-389. PMID: 28925645.