Not all of these symptoms need to be present for a diagnosis of vitamin B-12 deficiency - in fact, many people only have two or three.  If you suspect you have vitamin B-12 deficiency, ask your doctor for a blood and urine test - blood levels may not be accurate in all cases.

Neurological Symptoms:

• Numbness or tingling in the hands and feet.
• Problems coordinating your body movements (ataxia).
• Impaired reflexes.
• Problems walking (gait disturbances).
• Impaired vibration perception.
• Closing your eyes makes you very unsteady (positive Romberg's test).
• Extending your big toe while curling the rest when your sole is tickled (Babinski's sign).
• Sudden electricity-like shocks down the spine when moving your head.
• Degraded vision (optic nerve damage).

Pscyhiatric Symptoms:

• Difficulty concentrating.
• Confusion.
• Irritability.
• Impaired memory / memory loss.
• Dementia.
• Depression.
• Major personality changes.
• Psychosis/delusions.

Anemic Symptoms:

• Fatigue.
• Apathy.
• Difficulty breathing during exertion.

Other Symptoms:

• Aversion to meat (the only significant dietary source of vitamin B12).
• Impotence.
• Incontinence / loss of bladder control.
• Infertility.
• White patches of skin (vitiligo).
• Diarrhea.
• Hair loss.

Related posts:

1. Fatigued? Low Energy? Vitamin B-12 Can Help!
2. Fatigue, B-12 Deficiency & Pernicious Anemia