I asked my neighbor weeks ago & forgot to post what she said. (I have been having a bad spell of "nincompoop-ism", alas.
Anyway, she (podiatrist) believes that osteoporosis in the feet is pretty much caused by the same things that cause it elsewhere. She mentioned inflammatory diseases like lupus & RA, right off the bat.
I think the other risks she mentioned were the ones we read about all the time, i.e., smoking, alcohol, genetic tendency, prolonged steroid use, age, Caucausian background, being female, and being post-menopausal.
She says proper shoes are essential for all sorts of reasons. (I snickered only slightly at this, as she does wear high-ish "msart" heels on dress occasions. But I love to tease & we're buddies, so I got away with that.)
Have you discussed the possibility of Fosamax or one of the other bone-builders with your drs? I've been on it for several years---boy, oh boy, was my GP shocked at my first DEXA test, about 7 yrs. back. Not good at all.
Anyway, how are you doing in general? With my best, Vee