Hello, and welcome to Mayo Connect. As a person who currently has adequate bone density, but is at risk for osteoporosis due to age, health conditions and heredity, I have wondered about Algae Cal Plus and other algae based supplements.

Currently I am taking Calcium Citrate plus Vitamin D & magnesium on the recommendation of my primary & my ortho. So I looked to see if there is clear evidence one way or the other about Algae Cal (which is chemically calcium carbonate.)

I went on a search to see if there is any published independent research that indicates calcium from algae is in any way superior to other forms. Nope - all the studies were by sellers of algae based calcium products, none I found met the requirements of an independent unbiased study.

Then I started reading what is published by Mayo, Harvard, Johns Hopkins, etc. No recommendations about using algae-based products. Mostly to be sure to take it with Vitamin D & magnesium to make it effective.

Here is what National Women's Health has to say: https://nwhn.org/have-you-ever-heard-of-algaecal-im-being-deluged-with-ads-saying-any-nutrient-supplied-in-natural-form-such-as-from-plants-is-better-absorbed-than-nutrients-supplied-from-rocks/

So - after an hour (about) at looking at this, I don't see a conclusive reason to change to something that will cost me 10 times as much as my current supplement. Have you asked the doc who diagnosed you what they recommend?
Sue