Advertisement

What are the symptoms of vitamin B12 deficiency?

Jill A. Grimes, MD
Family Medicine

There may be no symptoms of B12 deficiency. In severe cases, you may develop anemia. Often, there are nonspecific symptoms such as brittle fingernails, fatigue, and forgetfulness.

If you have a family history of true B12 deficiency, that is also a risk factor.

Kate Geagan
Nutrition & Dietetics

Symptoms of vitamin B12 deficiency include:

  • overall lack of energy
  • unusual mood changes
  • difficulty concentrating or remembering things
  • tingling or numbness in hands or feet
  • inflamed, red, cracked tongue

    Typical symptoms of vitamin B12 deficiency, also known as vitamin B12 deficiency anemia, include tiredness, lack of energy, light-headedness when standing up or exercising, diarrhea, constipation, appetite loss, weight loss, pale skin, swollen or red tongue, bleeding gums, difficulty concentrating and shortness of breath.
     
    If you’ve been deficient in vitamin B12 for a long time, you may have nerve damage. Symptoms of vitamin B12–induced nerve damage include tingling or numbness in hands and feet, balance problems, depression, confusion, irritability and, in severe cases, dementia.

    Continue Learning about Vitamin B12

    What is the recommended dietary allowance (RDA) of vitamin B12?
    Dr. David L. Katz, MD, MPHDr. David L. Katz, MD, MPH
    Preventive Medicine Specialist Dr. David Katz discusses the recommended dietary allowance (RDA) of v...
    More Answers
    What is vitamin B12?
    Stacy Wiegman, PharmDStacy Wiegman, PharmD
    Vitamin B12, or cyanocobalamin, is a prescription medication used to increase low vitamin B12 levels...
    More Answers
    How Is Vitamin B12 Deficiency Treated?
    How Is Vitamin B12 Deficiency Treated?
    Which Medications Affect the Absorption of Vitamin B12?
    Which Medications Affect the Absorption of Vitamin B12?

    Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.