> If we need at least 1500 mg of calcium, what would you eat daily to supply
> this amount?
>
> If I want to supplement calcium what is the most bioavailable calcium?

Before taking calcium supplements, read this:
www.beyondveg.com/cordain-l/prot-calc/prot-calcium-loss-1a.shtml

According to the Nutrition News Focus (12.13.02), coral calcium is not the
way to go:

"Coral Calcium is a Crock

A highly advertised supplement is coral calcium. Claims are made that it
makes you body more alkaline to resist disease; that it boosts your immune
system; that it helps you live longer; and that it cures almost anything
you've got.

People selling this stuff hope you don't know any science. Raising you
body's pH, even by a little, will kill you. Check any medical textbook if
you don't believe it. Some sellers claim coral has an identical composition
to human skeleton. This is patently untrue.

HERE'S WHAT YOU NEED TO KNOW: Your body handles coral calcium just as it
would any other calcium supplement. But coral reefs are protected by
international law, so where does this stuff come from and is it really
coral? Most likely it is limestone which was formed billions of years ago
from seashells and coral depositing on the ocean floor and just happens to
be the source of inexpensive calcium supplements. Run, don't walk away from
coral calcium."

Rob