My calcium levels remain at normal ranges with Tymlos. But I believe we are all different and react to meds differently. There are only a few bone building meds and because my numbers were so bad my doc had to appeal our insurance because they wanted me to start with Fosamax and my doc said absolutely not. Would have prolonged my bone loss. So I’m almost done with my 2-year Tymlos protocol and have increased the bone density in my spine.