Fun Fact Friday! Ever wondered Why is my B12 injection red? All B12s are cobalamins they have a cobalt atom at the center of a special ring shaped molecule called Vitamin B12 Injections: What You Need To Know B12 Injections: Who Should Get Them and How Long Do They Last? Subcutaneous Injection Sites and Instructions for Safe Self Administration B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Subcutanous injection self administration South Tees Hospitals NHS Foundation Trust