The virus seems to attack any organ in your body that is under stress, and vitamine D deficiancy seems to lead to a cytotoxic shock (your killer t cells eat your lungs). It's a good virus to deal with everyone with any autoimmune problems too. The blood type also apparently matters, there are hardly any O- that have died.
Interestingly enough, users of nicotine appear to suffer less issues, which goes against the first parts, since smokers lungs are usually a problem to begin with, and in Sweden, users of snuff (the snuff you put under your lip) appear to get less issues overall.
I eat 5, 300 calorie meals per day, no meat, aim for 30% protein, no sugar added drinks or snacks, no artificial sweeteners. I've dropped from 246 to 195 since mid January. Excercise...20 to 60km of biking daily.