Vitamin B12(cobalamin) is referred to as a B complex vitamin. Cobalamin helps support the nervous system's health, red blood cell production, and DNA synthesis. Deficiency of vitamin B12 and cobalamin can cause many health-related problems. People take oral supplements to deal with the shortcomings of this vital vitamin. Vitamin B12 injections are an effective alternative, particularly for individuals with absorption issues or severe deficiencies.