One thing I would add is that bone density and bone quality are two different things. You can further help yourself by ensuring you get enough boron, magnesium, vit K, iron, vit D and calcium. There is a lot of research to suggest that collagen and turmeric help with bone density. The irony is that many fractures occour among the population with 'normal' bone density.
I would not touch bisphosphonates as the mechanism 'holds onto' the poor quality bone which would normally be jettisoned. It increases the density but by keeping poor quality bone. You need something anabolic which encourages new bone. If you take the drugs at all. There are many things you can do including the HRT to improve your numbers. You can have high quality less dense bones which won't break.