There are millions of people in America alone with PN, but doctors (thousands?) who keep prescribing drugs or statins which cause it. On top of that you have widespread blissful ignorance about B12 deficiency, including those fools on The Doctors. Count yourself lucky then if you can find a doctor who orders any kind of test related to PN. So glad to be living in the internet era; I'd know nothing without it. I wouldn't even know which books to look for at a library. (There aren't many books on PN, anyway.) I hope MrsD can write a book on it... like that person at stopthethyroidmadness did b/c of so many doctors' miserable failures.