Vitamin B 12 intramuscular injections are also used therapeutically to help restore energy and combat various symptoms related to such deficiencies. Vitamin B 12 is essential to the development of healthy blood cells, nerve Vitamin B12 and Acne Sudden red spots in skin + high B12 can be linked to liver stress or inflammation. It's not a diagnosis on its own but a signal to investigate further. Red Spots on How Often Should I Get a B12 Shot? An Expert Guide