Vitamin B-12, also known as cobalamin, is a water-soluble vitamin essential for various bodily functions. It plays a key role in producing red blood cells, maintaining a healthy nervous system, and synthesizing DNA. Vitamin B-12 is primarily found in animal-based foods such as meat, fish, eggs, and dairy products. It's crucial for energy production and overall health, and a deficiency can lead to anemia, fatigue, and neurological issues.