Members of the vitamin B complex are water-soluble vitamins. Water-soluble vitamins are those vitamins that dissolve in water and are easily absorbed in the body. They are not stored in large amounts in the body, so excess amounts are eliminated through urine. The B complex vitamins include thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), and cobalamin (B12). These vitamins play important roles in energy metabolism, nerve function, and DNA synthesis, among other functions. Because they are water-soluble, it is important to consume these vitamins regularly through a balanced diet that includes foods such as whole grains, nuts, seeds, legumes, and leafy green vegetables, as well as fortified cereals and animal products such as meat, fish, and dairy.