Carbonate or Citrate?
There is a difference
Calcium supplements usually contain one of two forms of elemental calcium, either calcium carbonate or calcium citrate.
Caltrate® is a calcium carbonate product; it's a smaller tablet with a more concentrated form of calcium so you can take fewer tablets to get the recommended amount. And fewer tablets mean your bottle of Caltrate® may last longer.
Compare the two forms:
Calcium carbonate - Caltrate® A concentrated form of calcium, yielding about twice the amount of elemental calcium than equal amounts of calcium citrate.
Calcium citrate A bulkier form of calcium, yielding about half the elemental calcium than equal amounts of calcium carbonate. You need to take more tablets or larger tablets.