VITAMIN B12 or cyanocobalamin
*Vitamin B 12 is essential for normal haemopoiesis and maintenance of normal integrity of
the nervous system.
*Vitamin B 12 belongs to the family of cobalamins. It is found only in trace amounts in tissues.
*The main sources of vitamin B 12 are animal proteins and dairy products.
*Vitamin B 12 is stored in the liver
*Normal daily requirement of vitamin B 12 is 1-2 μg.
DEFICENCY OF VIT B12
**Haemopoietic
• General symptoms and signs of anaemia
• Pallor of skin and mucous membranes
• Megaloblastic macrocytic anaemia
• Pancytopenia
• Splenomegaly
**neurological
• Paraesthesia of fingers and toes from peripheral neuropathy
• Signs of subacute combined degeneration of the spinal cord
• Dementia, depression, irritablity
or
*Glossitis, skin hyperpigmentation
• Intermittent soreness of tongue
• Smooth atrophic tongue
• Raw and red tongue during attacks of glossitis
• Periodic diarrhoea
Diagnosis
• Macrocytic anaemia.
• Hypersegmented neutrophils in peripheral smear.
• Pancytopenia. Myelodysplastic syndrome (MDS) and aplastic anaemia may also present with macrocytosis
Schilling test
Elevated serum methylmalonic acid (MMA)
treatment
Vitamin B 12 therapy
Initial dose of hydroxocobalamin is 1000 μg, deep intramuscularly daily for 1 week
Maintenance dose is 1000 μg of hydroxocobalamin intramuscularly once in a month
Iron therapy with ferrous sulphate 200 mg thrice daily orally should be started
