B12 defiency Flashcards
Role of B12 in the body?
mainly used in the body for red blood cell development and also maintenance of the nervous system.
How is B12 absorbed?
absorbed after binding to intrinsic factor (secreted from parietal cells in the stomach) and is actively absorbed in the terminal ileum. A small amount of vitamin B12 is passively absorbed without being bound to intrinsic factor.
Causes of vitamin B12 deficiency
pernicious anaemia: most common cause
post gastrectomy
vegan diet or a poor diet
disorders/surgery of terminal ileum (site of absorption)
- Crohn’s: either diease activity or following ileocaecal resection
metformin (rare)
Features of vitamin B12 deficiency
macrocytic anaemia
sore tongue and mouth
Neurological symptoms
- the dorsal column is usually affected first (joint position, vibration) prior to distal paraesthesia
- Neurophsyciatric symptoms eg. mood disturbances
Features of vitamin B12 deficiency
macrocytic anaemia
sore tongue and mouth
Neurological symptoms
- the dorsal column is usually affected first (joint position, vibration) prior to distal paraesthesia
- Neurophsyciatric symptoms eg. mood disturbances
Management: B12 deficiency
if no neurological involvement 1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months
if a patient is also deficient in folic acid then it is important to treat the B12 deficiency first to avoid precipitating subacute combined degeneration of the cord