Risks and Side Effects While generally safe, vitamin B12 injections can have side effects or risks, such as: Mild pain, swelling, or redness at the injection site Dizziness, headache, or nausea Allergic reactions (rare) Hypokalemia (low potassium levels) in individuals with severe deficiency undergoing treatment People with allergies to cobalt or who have Lebers disease should avoid B12 injections unless specifically advised by a doctor
Since it is a naturally occurring antioxidant in the body, side effects are rare, and the risk of adverse reactions is minimal
Mitra S, Chakraborty AJ, Tareq AM, Emran TB, Nainu F, Khusro A, et al
Restrictions For research use only
Emergency surgical teams are trained to manage this
Clinicians should review official safety labeling when evaluating suspected drug-related rashes