Calcium Carbonate or Calcium Citrate?

The difference between calcium supplements.

 
 
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Calcium supplements predominately contain two forms of elemental calcium, either calcium carbonate or calcium citrate. Calcium carbonate, the form of calcium found in Caltrate®, is the most concentrated form and is commonly found in food and drug stores.

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 amounts of calcium. And fewer tablets mean your bottle of Caltrate® may last longer.

Caltrate®: Smaller size, made possible by using a more concentrated form of calcium than citrate products.

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 carbonate products generally come in smaller size tablets than products using calcium citrate because they have a higher concentration of calcium.

Calcium citrate
A bulkier form of calcium, yielding about half the elemental calcium than equal amounts of calcium carbonate.

Calcium citrate products are generally bulkier than calcium carbonate products with the same amount of calcium so, to get the same amount of elemental calcium, you need to take more tablets or larger tablets.