@yvettemas1948
Well all strontium is the same strontium. What changes are the additives. AOR has the least additives and is monitored by an FDA like agency in Canada which monitors supplements. Vitacost has a strontium citrate at a good price point and FDA monitors it like a food product rather than a medicine. I have used both brands with no problems.
It is good to remember that the research shows that 3 capsules, 680 mg is what has worked for osteoporosis; other research seems to indicate that a half dose will work for osteopenia. Mots, Comb are two research studies which evaluate strontium citrate.
But any amount of strontium citrate will help bones; it is just that osteoporosis bones have large "holes" that the full dose of strontium is shown to work well to close and then allow calcium to adhere and bone can grow.
Also, it is good to remember that the one study on the pharma drug strontium ranelate which contained aspartame, which you seem to quote which showed some heart problems has never been able to be reproduced; it is now considered an outlier in research circles. Denmark tried for over a year to reproduce those results in their population study and they could not. I would never personally never take strontium ranelate with aspartame. Strontium citrate has never been tied to any cardio events, but more research would certainly be welcomed. Also realize that most of the earth has huge pockets of strontium in their ground water and there has never been pockets of cardio problems documented in those areas.
But check your diet or supplements and be sure to include enough calcium. Cronometer has a good free app that will chart your daily diet and your supplements and give you insight into what you may need, if anything.