Calcium -elemental and sources

[Guest guest]

Some calcium labels list how much elemental calcium is from the

source. Example brand " x " says there is 1200 mg of calcium citrate

in

one dose. Below that it says that 21% is elemental (so 252 mg).

On a tums EX tablet it says it contains 750 mg. of calcium carbonate.

Then below it says it contains 300 mg of elemental calcium. (or 40%

elemental).

My question is this:

Are we trying to meet the Recs. for calcium (1500 mg for RYN G-Byp.)

based on elemental amount? If that's the case, one would have to

take

4-5 times the dose of many calcium supplements, right? And what about

labels that don't list the amount of elemental calcium in the source?

How do we know the amount elemental? Is carbonate always 21%

elemental and citrate 40%, as in the example above?

Please advise.