It can also be caused by just being ill. I have been having terrible pallor for the last several months and my doctor and I discussed it. I made him check for pernicious anemia because my grandmother had it. My B12 is low, but I do not produce the antibodies. He said that pain and just not feeling well for a while can cause a pallor. However, we have never checked my iron levels, so it could be that. I know that when I am in pain, I get a white ring around my mouth. It is weird looking, but it is how I know when my pain is for sure bad, and not just me feeling wimpy at the moment!