Vitamin B6 is a vitamin that’s used to produce pyridoxine—a component of amino acids that helps form the basis of DNA, the blueprint for cell production. As such, vitamin B6 can be regarded as playing a critical role in forming all the new cells in the body. Vitamin B6 is also a component in immune system cells. And it has another job too: It’s involved in making heme, which is part of hemoglobin, the compound in red blood cells that transports oxygen throughout the body.