Symptoms of Vitamin B12 Deficiency
The initial symptoms of vitamin B12 deficiency are insidious and could easily be overlooked. The classical symptoms of anaemia are by no means obligatory. Early symptoms/findings of anaemia may also be masked by excess folic acid, or concurrent iron deficiency. Diffuse neuropsychiatric symptoms may often be the earliest symptoms.
The commonest neurological symptoms in vitamin B12-deficiency are paraesthesia of the hands and feet, diminished perception of vibration and position, absence of reflexes, and unsteady gait and balance (ataxia), but the range of symptoms is broad.
The psychiatric symptoms associated with vitamin B12 deficiency are also varied and fall into several different clinical categories. Confusion and memory disturbances are the most common. Depression, with or without psychotic components, and cognitive decline are frequent. Swings in mood and personality changes may be early signs of what may later be manifested as psychiatric disease. Such vague symptoms of vitamin B12 deficiency are easily overlooked, especially as the serum concentration of vitamin B12 can lie within the reference range.
Many disorders in the gastrointestinal tract can give rise to a deficiency of vitamin B12. Symptoms from the gastrointestinal tract, more or less pronounced, may be present, as well as poor mucosal function with subsequent specific symptoms such as glossitis.
Elderly persons are especially at risk of developing a vitamin B12 deficiency. Age-related, often asymptomatic atrophic gastritis is common and may be enough to cause a patient to slide slowly into a negative vitamin B12 balance with depleted stores of the vitamin, giving rise to vitamin B12 deficiency.
Infants of vegetarian/vegan mothers are also in danger of developing vitamin B12 deficiency, even though their mothers may not suffer from disorders of B12 absorption and do not show any deficiency symptoms. This is due to the relatively high requirement in the rapidly growing child.
Vitamin B12-deficiency concomitant with auto-immune diseases other than pernicious anaemia is often seen (eg. thyroid disease).
At risk groups
Patients at risk for B12 deficiency should raise the index of suspicion. These include the elderly, vegetarians and vegans, patients with intestinal disease and after surgery to stomach. Other groups include those with autoimmune thyroid disorders, hypothyroidism, patients on long term therapy with protein pump inhibitors and histamine receptor antagonists (particularly the elderly) and patients using biguanides for glycemic control.
Symptoms/conditions where vitamin B12 deficiency could be suspected.
Numbness in hands and feet
Impaired vibration perception
Positive Romberg´s test
Aversion to meat
Loss of appetite
Loss of weight
Atrophy of the mucosa
B12 LEVELS FALSELY ELEVATED IN PERNICIOUS ANAEMIA
A new publication has demonstrated that five different Total B12 assays gave normal B12 results in a patient with confirmed pernicious anaemia. To access the paper click here.
EXPERTS AGREEMENT ON UTILITY OF ACTIVE-B12
An experts meeting at a recent conference produced a Consensus Statement on the improved utility of the Active-B12 assay over Total B12. To see the statement click here.