Copyright ©The Author(s) 2017.
World J Gastroenterol. Jan 28, 2017; 23(4): 563-572
Published online Jan 28, 2017. doi: 10.3748/wjg.v23.i4.563
Table 1 Clinical and laboratory findings in vitamin B12 deficiency
General symptomsWeight loss observed in most patients
Low-grade fever occurs in one third of newly diagnosed patients and promptly disappears with treatment
Gastrointestinal symptomsSmooth tongue (50% of patients) with loss of papillae. Changes in taste and loss of appetite
Patients may report either constipation or having several semi-solid bowel movements daily
Anorexia, nausea, vomiting, heartburn, pyrosis, flatulence and a sense of fullness
BrainAltered mental status. Cognitive defects (“megaloblastic madness”): depression, mania, irritability, paranoia, delusions, lability
Sensory organsOptic atrophy, anosmia, loss of taste, glossitis
Bone marrowHypercellular bone marrow
Increased erythroid precursors
Open, immature nuclear chromatin
Dyssynchrony between maturation of cytoplasm and nuclei
Giant bands, metamyelocytes
Karyorrhexis, dysplasia
Abnormal results on flow cytometry and cytogenetic analysis
Spinal cordMyelopathy
Spongy degeneration
Loss of proprioception: vibration, position, ataxic gait, limb weakness/spasticity (hyperreflexia)
Positive Romberg sign
Lhermitte’s sign
Segmental cutaneous sensory level
Autonomic nervous systemPostural hypotension
Peripheral nervous systemCutaneous sensory loss
Hyporeflexia symmetric weakness
Genitourinary symptomsUrinary retention and impaired micturition may occur because of spinal cord damage. This can predispose patients to urinary tract infections
Reproductive systemInfertility
Abnormalities in infants and childrenDevelopmental delay or regression, permanent disability
The patient does not smile
Feeding difficulties
Hypotonia, lethargy, coma
Hyperirritability, convulsions, tremors, myoclonus
Choreoathetoid movements, peripheral blood
Macrocytic red cells, macro-ovalocytes
Anisocytosis, fragmented forms
Hypersegmented neutrophils
Leukopenia, possible immature white cells
Elevated lactate dehydrogenase level (extremes possible)
Elevated indirect bilirubin and aspartate aminotransferase levels
Decreased haptoglobin level
Elevated levels of methylmalonic acid, homocysteine, or both