@mcallister1002

Strontium density and dexa readings:
Yes, strontium is denser than calcium and skews the dexa because of how the radiation in the dexa reacts to the denser material. But REMS and TBS are not affected in this way and they show good results with good bone quality for strontium users. Plus, the bone biopsies done also show good bone quality and density.

Kidney Stones:

Well, algae Cal has many products, some of which have calcium. So not sure what the kidney stone connection might be in their self reports.
Interestingly, the research is mixed ...while some evidence links strontium to kidney stone composition, other research suggests that higher urinary strontium might be associated with a lower risk of chronic kidney disease (CKD) rather than causing stone issues directly.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10534960/.
Like calcium, the link between strontium and kidney health is more closely tied to general kidney function than to the specific formation of stones. Most meds and supplements need to be evaluated before use with lower kidney health. I do not think that strontium differs in this way.

Interestingly, in some recent research:
Chronic Kidney Disease (CKD) Association: A large-scale cross-sectional study of the U.S. population found a negative correlation between urinary strontium and CKD, meaning those with higher urinary strontium actually had a lower risk of CKD.
https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2023.1251232/full