Vitamin B 12 Cyanocobalamin Injection 1000MCG mL 30 mL MDV Med Plus Physician Supplies Home The B 12 Store Cyanocobalamin is the preferred supplemental form of vitamin B 12 as there is insufficient evidence to support the efficacy of the other forms like methylcobalamin. Michael Greger MD, How Not to Die. Cyanocobalamin (B12) Injection 1000 mcg mL, Multiple Dose Vial 30 mL McGuff