I looked up your product, and as usual Magnesium oxide is listed first under magnesium. When products do this, combine 3 types of magnesium they don't tell you how much of each you are getting.

here is a link to the label ingredients:
https://www.shaklee.com/pws/library/...0681_label.pdf
(use the magnifier in your tool bar to enlarge this PDF)

The ingredient list contains the newer mix of support minerals for bone
health. And be advised to read carefully...you have to take FOUR tablets to
get what is on that label.

Here is a monograph to read about safely using high dose calcium:
http://www.drugdigest.org/DD/DVH/Use...Plus+D,00.html

There are limits to absorption of calcium in the GI tract, so dividing up the tablets thruout the day may give you more effect.

I suspect the elemental magnesium is low in this mixed product. Most mixtures use inexpensive mag oxide, and very little of the chelates. Chelated magnesium is typically a very large tablet, so size also enters into the decision.