I too had terrible Dexa Scan result. I have not returned to see if it has changed.
What I do is lift heavy weights. Unfortunately I cannot squat over 315 because my back is broken at the L-5 vertebrae. I have fooled around with 400 and the research says heavier the weight the more effective it is at increasing density. I just try to do 315 20 times and eat good. Some day I will check it again with another Dexa Scan but I sure will never take prednisone again./www.builtlean.com/2013/12/11/weight-lifting-bone-density/..the vast majority of research supports resistance training as a very effective means to increase bone density
There are other benefits as well and you can just start with nothing and work your way up.