The virus was harder on the Knox because they have low vitamin D because they can't make vitamin D with their dark skin as well as white people can and because they're hugely overweight. Second on the list was people who had had not been out in the sun or who had already used always use sunscreen and also had low vitamin D and we're hugely overweight. One of the reasons being overweight is a factor is because vitamin D is diluted by fat so you have to intake a lot more vitamin D or produce a lot more vitamin D if you're going to spread it around an extra 50 or 100 pounds of body weight. Because with vitamin D what counts is the concentration you have in the fluid in your body. So if you got a lot more fat you got to have a lot more vitamin d.