Vitamin B12 reviewed

Cobalamin or vitamin B12 deficiency is common in elderly patients but because of the varied manifestations of this condition may not be recognised. There is a very good review in the QJM by Dali-Yousef and Andres detailing the wide range of clinical, some subtle consequences of B12 deficiency.
There is the classical but uncommon pernicious anaemia, but more commonly food-cobalamin malabsorption, that is an inability to release cobalamin from food or its binding proteins. This is usually a consequence of atrophic gastritis, possibly related to helicobacter pylori infection and long term use of acid suppressors.
There are also mutations in the genes controlling the B12 receptors in the ileum responsible for B2 absorption.
The deficiency may be identified by serum B12 concentrations and maybe in addition serum homocysteine concentrations.
The clinical manifestations are wide but include
Fatigue, sensory neuropathy,
Combined sclerosis of the spinal cord
Haemolytic anemia
This deficiency must be looked for where there are neurological conditions.
Dali-Youcef and Andres 209 An update on cobalamin deficiency in adults QJM
vol 102, pp 17-28.

Martin Eastwood
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