Vitamin B12 deficiency symptoms include:

• Loss of appetite
• Diarrhea
• Numbness and tingling of hands and feet
• Paleness
• Shortness of breath
• Fatigue (this is due primarily to the anemia)
• Weakness (this is due primarily to the anemia)
• Sore mouth and tongue
• Confusion or change in mental status in severe or advanced cases. This is sometimes confused with dementia.