Vitamin B Complex 100 Injection (with Dexpanthenol), Multiple Dose Vial 30 mL McGuff Vitamin B12 Injection treat harmful anemia plus B 12 insufficiency Treatment with high dose vitamin B12 been shown to be safe Vitamin B12 Vitamin D Life 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.