B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn Vitamin B12 Injection at BiosenseClinic.com a Licensed Pharmacy B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics Vitamin B12 Injections: What You Need To Know How to Give Yourself Intramuscular (IM) Injections Patients & Families UW Health Vitamin B12 is absorbed through two pathways. The first is intrinsic factor, a protein produced by parietal cells in the stomach. IF binds B12 in the small intestine and carries it across