How often should vitamin B12 injections be administered and how frequently should laboratory monitoring be performed? How Often Should You Get B12 Injections? Infusion For Health Methylcobalamin B12 Injection in Beverly Hills, Arcadia and Los Angeles County California Infusion Centers If you have a low vitamin B12 level, injections can go a long way toward improving your health and well being. But if your B12 level is normal, don't fall for claims that