Why Vitamin B12 Deficiency Should be on your Radar Screen

<strong>Vitamin</strong> <strong>B12</strong> <strong>Deficiency</strong>
Detection and Diagnosis
“It is particularly important that the diagnosis of
cobalamin deficiency <strong>be</strong> established with a high degree
of certainty <strong>be</strong>cause cobalamin therapy almost always
must <strong>be</strong> given for the life-time of the patient.”
Stabler and Allen, 2004
Keeping vitamin <strong>B12</strong> deficiency on your radar screen
means staying vigilant during your review of your
patient’s history and during the physical examination.
Watch for even subtle signs of neurologic or cognitive
impairment. Also, note any elements of the patient’s
history that might suggest potential malabsorption or
malnutrition, such as previously diagnosed pernicious
anemia, previous gastrointestinal surgery, vegan diet,
and advanced age. Maintain an especially high index of
suspicion of vitamin <strong>B12</strong> deficiency in new patients who
report they were treated with vitamin <strong>B12</strong> injections or
high doses of oral vitamin <strong>B12</strong> supplements by a former
provider, but have since discontinued their use. Elderly
patients often fail to understand that a true
vitamin <strong>B12</strong> deficiency due to malabsorption
requires lifelong treatment.
Early detection and prompt treatment of a vitamin <strong>B12</strong>
deficiency are essential to prevent development of
irreversible neurologic damage, but making an accurate
and timely diagnosis can <strong>be</strong> challenging. The list of
related signs and symptoms is long, varied, and nonspecific.
Many risk factors have <strong>be</strong>en identified, but
there are no known necessary or sufficient causes.
Complicating things further is the fact that <strong>be</strong>cause the
liver is a very efficient storage organ for vitamin <strong>B12</strong>,
even completely deficient diets in healthy adults might
not result in low serum vitamin <strong>B12</strong> levels for several
years. Conversely, apparently healthy adults, especially
the elderly, consuming diets rich in naturally occurring
vitamin <strong>B12</strong> can still develop a significant deficiency
<strong>be</strong>cause of undetected malabsorption. It is possible for
vitamin <strong>B12</strong> deficiency to develop in a much shorter
period of time (months) in some people.
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