The Side Effects of Vitamin B12

4. Injection Site Reactions

For individuals who cannot meet their body’s vitamin B12 needs through diet alone, B12 injections are often prescribed. While generally safe and well-tolerated, these injections can occasionally cause minor side effects at the injection site, such as itching, swelling, or mild irritation.

These symptoms typically subside within a few hours and rarely require medical attention. However, if the reaction worsens or becomes painful, it’s important to contact a healthcare provider for guidance.