There are probably millions of claims - on the internet, TV, blogs, in magazines - for this supplement vs that supplement...
We need to do our research because so many are either promotions, puffery, or one person's opinion.
When considering supplement which to use, whether calcium or any other, we must rely on scientifically valid research, done by qualified medical or scientific personnel, which actually test the effectiveness and safety of each product, including reporting unbiased results from unbiased studies.
AlgaeCel and many other "new" products have not been proven to have better results than the cheaper, older versions in real studies - https://naturalmedicines.therapeuticresearch.com/news/news-items/2020/january/is-algae-a-good-source-of-calcium.aspx They just cost a lot more.
So, if you want to know what to use, look for unbiased, peer-reviewed studies comparing the advertised product to the old stand-by ones. Over a significant period of time (year or longer.) Among a large and diverse group (not 25 people they selected.) Make sure real, tested berfore-and-after numbers are reported.
Jumping off the soap box now.
Sue