Vitamin B6 is an essential, water-soluble nutrient that plays a crucial role in the body. It is involved in more than 100 enzymes needed for protein metabolism and red blood cell production, and helps the immune and nervous systems stay healthy. Vitamin B6 is vital for converting tryptophan to niacin, as well as helping to maintain normal blood glucose levels, especially when daily caloric intake is low. By aiding protein metabolism and cellular growth, B6 also supports healthy functioning of lymphoid organs.