Table 2: Selected symptoms of vitamin B12 deficiency and/or hyperhomocysteinemia.

Category	Symptoms
Neurologica	Deterioration of the myelin, cognitive decline (e.g. memory loss), confusion, speech impairment (slurring), difficulty walking, inability to feel the ground, tingling, paresthesia, difficulty concentrating, numbness in both legs, mood alteration/swings, muscle cramps, paralysis, electric shock sensations, jerking movements of abdominal muscles, anxiety, depression, clumsiness, visual impairment, gait, shooting pain in calves, difficulty falling asleep, restless leg syndrome, optic neuropathy, subacute degeneration of the spine
Psychiatric	Disorientation, hyperactivity, decreased need for sleep, reckless and agitated behavior, social withdrawal, decreased interest, apathy, suspiciousness, hearing voices, hallucinations, anhedonia
Oral	Glossitis, pain and burning sensation in tongue, burning mouth syndrome, gradually progressive hoarseness, difficulty eating, red stains on inside of cheeks and tongue/glossitis/beefy tongue with U-shape streaks, oral epithelial dysplasia, cheilosis
Dermatological	Hyperpigmentation (blackish discoloration of the skin on knuckles, darkening of hands, feet, and tongue), skin lesions on feet, neck and upper and lower limbs, vitiligo foci (white patches on skin)
Hematological	Pancytopenia (low count of all blood cell types), macrocytic anemia, hyperhomocysteinemia
Other/rare	Anorexia, exercise intolerance, urinary incontinence, persistent watery diarrhea, normal blood pressure in supine position and rapid blood pressure drop in standing up position