I don't have OP, but years ago from a bone density test, I had signs of osteopena, with aging we all lose some bone density. I'm an inch shorter than I've been all my life, but lost some height with hip job too.

I don't take large amounts of calcium but do dose higher in magnesium and often dose with Strontium Citrate. I know of other people who use Strontium as well. It's OTC and do your research. In spite of it all, I have good straight back/posture. Good to do some stretches and weight bearing work for bone health. Just an FYI