November 12, 2012

Symptoms of Vitamin B12 Deficiency

What Are The Symptoms of Vitamin B12 Deficiency?

In this Blog Update we will briefly look at the various symptoms and signs associated with Vitamin B12 deficiency. These are very varied, because the deficiency can affect many different body functions:


Because prolonged B12 deficiency is a cause of anaemia, its symptoms can include weakness, tiredness, breathlessness on exertion and even palpitations (awareness of ones heartbeat).

Gastrointestinal tract symptoms:

Deficiency can also be associated with a loss of appetite, sore mouth and tongue, upper abdominal discomfort, nausea, vomiting and heartburn.

Neurological symptoms:

Because Vitamin B12 is needed for a healthy nervous system, deficiency can also cause numbness of extremities, pins and needles, impaired fine finger movements and ataxia (an unsteady gait).

Behavioural and psychiatric symptoms:

Deficiency of vitamin B12 can also present with complaints of irritability, memory loss and intellectual impairment, word finding difficulties, disorientation, depression, dementia and delirium.

Blood and Nerves:

Broadly speaking, Vitamin B12 deficiency predominantly affects blood (haematological tissue) and nerve cells.  During the last 30 years or so it has been discovered that the neuropsychiatric symptoms are often the very first clinical manifestation of B12 deficiency.

There has also been scientific interest in the fairly common observation of a “dissociation” of neurological and haematological features of B12 deficiency.  This is partly a result of improved methods for diagnosing and monitoring the deficiency (See - Vitamin B12 in Neurology and Ageing; Clinical and Genetic aspects).


We will take a closer look at these relatively new diagnostic techniques in future Blog updates.

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