B 12 (Methylcobalamin) Therapy MedClub by Dr Jenn When to use CPT code for B12 injection Medical Coding Guide Benefits of a Vitamin B12 Injection, Vitamin B12 injections are commonly used for people who are deficient, struggle to absorb B12 from tablets, or require a faster and more effective boost., Helps B 12 Compliance Injection: Package Insert Prescribing Info Vitamin B12 1000mcg Injection Rx PBS Animal Health