P 2: This is essentially what i've been saying all along.

P 3: I understand your ideas on iron levels in his body & resistance to zedism. What im saying is that there really isnt enough information to come up with anything but pure conjecture. When you figure in rationing, availability of types of food, any special stores he may have been given (all pieces of information we are either missing, or woefully uninfromed on), the only significant difference in diet (that we can be reasonably sure of) between tommy and everyone else is what he WASN'T eating: carbohydrates, mostly. So, yes, iron intake may very well play a part but given the same information one could also conclude that carbohydrates may speed up the process. My point is that it's really tough to even theorize about this without more info. So i guess my advice would be to look at the different quirks/habits of those characters who DO turn, and see if we can find a common thread to tie it to your theory.