Rose,
All strontium is the same strontium. What differs is the government regulation, the price and the additives in the product.

AOr has the best government regulation in Canada and the fewest additives. Vitacost has a good price point and easier to obtain than the AOR from Canada. I have taken both AOR and Vitacost.

Blood clots....no I am not concerned. This is why,,,, no research on strontium citrate has ever shown any cardio problems. Plus,,,,,The single research that talked about bloot clots was a population study on strontium ranelate, with the additives of ranelate and aspartame, problems of their own.
Plus...
That one population study which found strontium ranelate with cardio problems was a population study with no control group and included participants with existing heart problems which is usually considered as a contraindication in most research within the type of context.

So in an older population with lots of heart problems the population study found, viola, heart problems. The medical community in Europe was concerned enough that they performed several other population studies but used a control to eliminate those with existing cardio problems. The study in Denmark, 2005-2011 found no cardio problems. Subsequent research duplicated this finding of no cardio problems arising from use of strontium ranelate.
https://pubmed.ncbi.nlm.nih.gov/24651624/
https://pubmed.ncbi.nlm.nih.gov/24322476/
https://pubmed.ncbi.nlm.nih.gov/20553059/
etc. etc..
Many doctors and research groups now consider that one study that showed cardio problems, among people who had existing cardio problems, as an outlier, and I saw one report with the word "flawed" being used. I do not view it quite that way since good information was given in that population study which led to better and more precise research. I do find it upsetting that the study showing cardio concerns is used so much by people on the internet who want to stop the use of strontium, all without ever mentioning the follow up studies that found no cardio correlation; I am afraid that money may play a role in this; supplements after all are not a big money generator for anyone. But the information and studies are there for the finding and now easily found with the search tools to which we all have access.

I would personally never take strontium ranelate, but this is moot because it is not available in the USA. Strontium citrate is available and has never been linked in research or use or population studies to cardio events.

Also, bear in mind that several osteoporosis pharma medications are associated with potential cardiovascular side effects, most notably Evenity, which carries a warning for increased risk of heart attack, stroke, and cardiovascular death. Other osteoporosis drugs with reported cardiovascular risks include Prolia with atrial fibrillation and Forteo with reported side effects of dizziness/fast heart rate.

Most drugs and supplements have some type of side effects. Water if overused can actually cause death.

So we have to analyze and decide what is best for us. That is hard to do when you are scared and shaken. I have taken drugs which I regret, and I now take my husband with me to appointments to have his ear, memory and his instruction for me to say "let me consider that recommendation, before I take it, thank you". I do this because I know that I am not at my best when I am stressed and in pain. Most of us have this problem.
Plus, deciding what treatment you want to use for your osteoporosis is a very personal decision and made up in large part to our emotions and what makes us feel safe. There are lots of good osteoporosis drugs that work well for most people.
I celebrate anyone's good news; We are in this together.