B12 is an essential precursor for the production of ATP, the body’s energy source. It is required for proper red blood cell formation, neurological function, cell metabolism, and DNA synthesis. Recommended for: When you’re feeling fatigued or feeling run down. B12 is a must for vegetarians or those who consume very little meat, after periods of heavy alcohol use, and for extra metabolism support. Get a B12 boost in your arm or add it to your drip!