Fast Five Quiz: Vitamin B12 Deficiency

Romesh Khardori, MD, PhD


December 22, 2020

Common presenting symptoms often include signs of anemia (eg, fatigue, pallor). Other presenting symptoms may include jaundice, peripheral neuropathy, glossitis, diarrhea, headaches, and neuropsychiatric disturbances.

Recognized clinical manifestations of vitamin B12 deficiency include the following:

  • Cutaneous

    • Hyperpigmentation

    • Jaundice

    • Vitiligo

  • Gastrointestinal

    • Glossitis

    • Diarrhea

  • Hematologic

    • Anemia (macrocytic, megaloblastic)

    • Leukopenia

    • Pancytopenia

    • Thrombocytopenia

    • Thrombocytosis

  • Neurological

    • Areflexia

    • Headaches

    • Cognitive impairment (including dementia-like symptoms and acute psychosis)

    • Gait abnormalities

    • Irritability

    • Loss of proprioception and vibratory sense

    • Olfactory impairment

    • Peripheral neuropathy

Read more about neurologic manifestations of vitamin B12 deficiency.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.