Vitamin B12 helps regulate the nervous system, reduces depression, maintains a healthy digestion systems, promotes skin, hair and nail growth. It protect against cancer, such as lung, prostrate, great for the colon. Vitamin B12 boosts energy production, while prevent strokes and maintain cholesterol levels. It is also great for preventing hangovers should you ingest it the night before, pill form is best for this. Great sources of vitamin B12 is spinach, eggs, raspberries, broccoli, tomatoes, mushrooms and cabbage.