Is a 1 mg intramuscular vitamin B12 injection safe for a pregnant woman with confirmed B12 deficiency and no known cobalamin allergy or severe renal hepatic impairment? What is a B12 injection? , A B12 injection delivers a concentrated dose of vitamin B12 directly into the muscle for rapid absorption and effective replenishment of levels in the body., Vitamin B12 B12 Injections at Home Safety Guide for Self Administration Infusion For Health Stay Active and Healthy with B12 Injection Viva Aesthetics & Wellness B12 Injections and IV Infusion Treatments to Boost Your Vitality