Vitamin B-complex refers to a group of water-soluble vitamins that play important roles in cell metabolism. This group includes B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate), and B12 (cobalamin). These vitamins are crucial for energy production, synthesis of neurotransmitters, and red blood cell formation. They are found in a variety of foods including whole grains, meats, eggs, dairy products, legumes, seeds, and leafy greens. B vitamins are essential for maintaining healthy skin, hair, and eyes, and they also support the nervous system. Deficiencies can lead to various health issues, including anemia, fatigue, and neurological disorders.