hi, I have read through your question and understood your concerns. It is right that strontium increases the bone cortical thickness but does not improve the density thus leaving more probability for bone fractures.More studies have been confirming this moreover stontium is a denser material and may show a false increase in density in a dexa scan. strontium having a same stucture a calcium competes with it for absorption therefore decreasing calcium absorption. vit-D3 with calcium is an effective combination for improving your bone health. Moreover recent studies found a relation that there was an improved cardiac health in patients who maintained a high level of vit-d3 in their plasma. you just need to drink a lot of water along with these supplements. as an excess of these supplements tend to form renal stones. wish you a speedy recovery..!!