Vitamin B12 (also known as Cobalamin) is a vitamin that's essential for many aspects of your health, though your body is unable to produce it. In order to maintain healthy levels of Vitamin B12, you need to make sure that you get enough from external sources, such as food and supplements. This vitamin has a wide variety of health benefits -- from boosting your energy to improving your memory -- leading some people to recommend vitamin B12 for weight loss.