Niacin, also known as vitamin B3, is an essential nutrient that plays a crucial role in converting food into energy. It helps the body use carbohydrates, fats, and proteins effectively. Niacin is found in various foods, including meat, fish, eggs, and whole grains, and can also be taken as a dietary supplement. In addition to energy production, niacin supports healthy skin, nerves, and digestion. It is important for the synthesis of DNA and the production of hormones in the adrenal glands. A deficiency in niacin can lead to health issues, including pellagra, which is characterized by symptoms like dermatitis, diarrhea, and dementia.