In some people, vitamin B12 might cause diarrhea, blood clots, itching, serious allergic reactions, and other side effects.
Vitamin B12 also appears to be safe when used on the skin for psoriasis. Mild itching has been reported in one person who used a specific avocado oil plus vitamin B12 cream for psoriasis.
Irritability, Insomnia, Sore muscles, Achy joints, Acne, Rash, Severe anxiety, Palpitations, Nausea, Headaches, Migraines.
Adverse Drug Reactions: Inform doctors about unexpected reactions after using drugs.