What is the recommended dose for a monthly vitamin B12 (cobalamin) injection ? Vitamin B12 Dosages: Your GoodRx Guide GoodRx Vitamin B12 injections deliver high doses of this essential vitamin directly into your bloodstream for better absorption than oral supplements to boost energy, support red blood cell production and maintain nerve function. B12 Injection Dose: 7 Key Guidelines for Adults and Common Prescriptions Liv Hospital Vitamin B12 Monthly Injection Dose: Typical Dosages & Administration Methods Liv Hospital