I don't think they diagnose toxic PN based on cigarette smoking, and people with toxic PN have exposure to some toxic substance that is known to cause PN. You could not say that those people with toxic PN due to other causes that happen to smoke got it from smoking.

The logistics of such a study would be substantial. It would be very difficult to statistically prove that cigarettes and cigarettes alone cause PN. It would almost have to be a longitudinal study, controlled for a great many variables.

I would not doubt that smoking causes or exacerbates PN, it causes a great deal of disease and suffering. To get a study controlled for variables to prove that it causes PN would be an undertaking!!

I was exposed to heavy smoking as a kid and was sick with respiratory illness my entire childhood. It is best not to smoke.

Oh MRSD, I had my yearly physical and without asking, they decided to run a Vitamin D level....so this will be interesting.