Vitamin B12 shots: Uses, benefits, and side effects Vitamin B 12 Cyanocobalamin Injection 1000MCG mL 30 mL MDV Med Plus Physician Supplies B12 Shot Guide: Benefits, Dosage & Side Effects BodySpec Ever wonder why B12 shots are red? Here's the scoop! , B12 injections naturally have a deep red color due to the presence of the cobalt corrin complex, a key component of its molecular structure. Do you know why vitamin B12 is red? Vitamin B12 (Methylcobalamin) is red in color because it contains cobalt (Co), a rare biochemical element, at the center of a porphyrin ring