Calcium Carbonate vs Calcium Citrate

Not all calcium supplements are created equal. Calcium carbonate, the form of calcium found in Caltrate^®, is the most concentrated form of calcium.

Calcium supplements are generally made with one of two sources 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.

Most formulas supply calcium in the form of calcium carbonate. Calcium carbonate, which is found in Caltrate^{® +++}, is more concentrated, allowing for smaller or fewer tablets.

And fewer tablets mean your bottle of Caltrate^® may last longer per bottle compared with other forms.

Let’s compare the two forms:

Calcium carbonate – Caltrate^®

• Concentrated form of calcium
• Yields about twice the amount of elemental calcium as equal amounts of calcium citrate
• Provides same amount of calcium in a smaller-sized tablet than products using calcium citrate

Calcium citrate

• Bulkier form of calcium
• Yields about half the elemental calcium than equal amounts of calcium carbonate
• Requires more tablets or larger tablets than calcium carbonate products to get the same amount of elemental calcium