B complex vitamins are a group of water-soluble vitamins that play important roles in energy production, brain function, and the health of the skin, hair, eyes, and liver. They are essential for maintaining good health and well-being, and they work together to support a variety of bodily functions.Here is a brief overview of the functions of each of the B vitamins:B1 (thiamin): Helps the body convert carbohydrates into energy and supports the functioning of the heart, muscles, and nervous system.B2 (riboflavin): Helps the body convert food into energy and is important for healthy skin, hair, and nails.B3 (niacin): Helps the body convert food into energy and supports the functioning of the nervous system and the skin.B5 (pantothenic acid): Helps the body convert food into energy and is important for the synthesis of hormones and cholesterol.B6 (pyridoxine): Helps the body convert food into energy and is necessary for the synthesis of neurotransmitters and the metabolism of proteins and carbohydrates.B7 (biotin): Helps the body convert food into energy and is important for the health of the skin, hair, and nails.B9 (folate): Helps the body convert food into energy and is necessary for the synthesis of DNA and the production of red blood cells.B12 (cobalamin): Helps the body convert food into energy and is necessary for the production of red blood cells and the proper functioning of the nervous system.B complex vitamins are found in a variety of foods, including meat, poultry, fish, eggs, dairy products, and leafy green vegetables.