Vitamin B3, also known as niacin, is a water-soluble vitamin that plays a crucial role in converting food into energy. It helps the body use carbohydrates, fats, and proteins effectively. Additionally, niacin supports healthy skin, nerves, and digestive systems, making it essential for overall well-being. This vitamin can be found in various foods, including meat, fish, eggs, and whole grains. It is also available as a dietary supplement. A deficiency in niacin can lead to health issues such as pellagra, characterized by symptoms like skin rashes, digestive problems, and mental confusion.