Possible Side Effects and Contraindications of B12:
- A vitamin B12 shot is safe and generally has no side effects, even in higher doses.
- Some redness and swelling at the injection site may occur. This should start to get better with-in forty-eight (48) hours.
- In rare cases, B12 can causes diarrhea, peripheral vascular thrombosis, itching, transitory exanthema, urticaria, feelings of swelling of the whole body.
- Sensitivity to cobalt and/or cobalamin is a contraindication.
- People with chronic liver and /or kidney dysfunction should not take frequent B12 injections; therefore, we ask that you please provide us with a recent copy of lab work, which reflects liver and kidney function. This lab work is usually referred to as a metabolic panel. If you have not checked your lab work recently, we ask that you get a complete blood workup as soon as possible.
- Drugs that decrease or reduce absorption of B12: antibiotics, cobalt irradiation, colchicine, colestipol, H2-blockers, metformin, nicotine, birth control pills, potassium chloride, proton pump inhibitors.
- B12 is contraindicated in Leber’s Disease (a hereditary optic nerve atrophic condition), clients with chronic liver and/or kidney dysfunction, or abnormal red blood cells (megaloblastic anemia).