All calcium supplements are not equal; some kinds are absorbed better by the body than others. Calcium Carbonate, the most widely used form of calcium, may not dissolve as easily in the stomach as calcium citrate or calcium gluconate, especially in the elderly. However, calcium citrate and gluconate are less concentrated than calcium carbonate. This means that you may have to take more of some kinds of calcium supplements than others to get an equivalent amount of this important mineral.
| PRODUCT | MG OF AVAILABLE CALCIUM |
| Caltrate 600 | Carbonate (600mg) |
| Caltrate 600 + Vitamin D | Carbonate (600mg) |
| Tums | Carbonate (limestone)(200mg) |
| Tums E-X | Carbonate (limestone)(300mg) |
| Tums 500 | Carbonate (limestone)(500mg) |
| Citracal | Citrate (200mg) |
| Citracal + D | Citrate (315mg) |
| Viactiv (chewable) | Carbonate (500mg) |
| Os-Cal or Os-Cal 500+D | Carbonate (oyster shell); This type may contain trace amounts of lead and should be avoided in pregnancy |
