Ultraviolet Blood (UVB) Irradiation is the procedure of exposing the blood to Ultraviolet (UV) light to increase the body’s immune response and to kill infections. With exposure to UV light, bacteria and viruses in the bloodstream absorb five times as much photonic energy as do red and white blood cells. Many bacterial toxins are stopped by UV light. UV light increases oxygen content in the blood. This further activates and directs your immune system to the specific infections the body is attempting to overcome.