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 What Happens If You Inject B12 Wrong: 6 Red Flags B12 vitamin Store Vitamin B12 injectable B Complex 30 ampules 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.