Fast Five Quiz: Vitamin B12 Deficiency Key Aspects

Romesh Khardori, MD, PhD


January 17, 2023

According to the AAFP, patients who have undergone bariatric surgery should receive oral vitamin B12 supplementation (1 mg/d) indefinitely. However, screening all average-risk adults for vitamin B12 deficiency is not recommended.

In patients with cardiovascular disease who have high serum homocysteine levels, vitamin B12 supplementation does not reduce the risk for myocardial infarction or stroke.

Initial laboratory assessment should include a complete blood count and serum vitamin B12 level. Serum methylmalonic acid assessment should be used to confirm vitamin B12 deficiency in high-risk patients with low to normal serum levels of vitamin B12, but it is not part of routine laboratory screening for all patients.

Intramuscular and oral administration of high-dose vitamin B12 (1-2 mg/d) both correct anemia. However, intramuscular therapy offers more rapid improvement and is used for patients who have severe neurologic symptoms and severe deficiency.

Learn more about the treatment 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.