The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Side effects aren't common.
Vitamin B12 serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious allergic reaction: rash; trouble breathing; swelling of the lips, tongue, or face; vomiting
Source: DailyMed
The following Vitamin B12 side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Other Vitamin B12 articles
Why trust our experts?
Reviewed by:
Robert Chad Hakim, PharmD, BCCCPRobert Chad Hakim, PharmD, BCCCP, started his full-time career as a clinical pharmacist at UCLA Health in the general medicine, general cardiology, and ICU units after completing residency in 2016. He also was the preceptor for the general medicine rotation from 2017 to 2021, which was a required rotation for all pharmacy residents.
Reviewed by:
Kristianne Hannemann, PharmDKristianne Hannemann, PharmD, is a licensed pharmacist in California. She has been a retail pharmacy manager and staff pharmacist for over 7 years and has contributed drug information content to different health companies.
