Normal adult including elderly and pregnant: 1000-1300mg daily
| Calcium Type | Elemental Calcium (%) |
| Calcium carbonate | 40 |
| Calcium citrate | 21 |
| Calcium lactate | 13 |
| Calcium gluconate | 9 |
-1500mg Calcium Carbonate= 600mg elemental calcium (1500 x 40%)
-Calcium carbonate needs to be taken with food as the absorption is better when the stomach is slightly acidity.
-Calcium citrate is soluble and does not require meals for absorption.
-Calcium supplement in liquid, powder and chewable tablet are more ready for absorption due to its dosage form.
-The absorption of calcium is also better if a smaller dosage is taken for each serving, for example 500mg (max).
Side effects
Constipation, flatulent and kidney stones.
Interaction of calcium with certain medicines
Reduced absorption of other medicines or supplements
- The absorption of some medicines like antibiotics (fluoroquinolone and tetracyclines – suggest at least a gap of 2 hours), thyroid hormone (levothyroxine – suggest at least a gap of 4 hours) and epilepsy medicines (phenytoin) can be reduced if taken together with calcium.
- Do not take iron supplements and antacids (calcium) or calcium supplements at the same time. It is best to space doses of these 2 products 1 to 2 hours apart, because calcium might inhibit the absorption of iron.
Reduced absorption of calcium
- On the other hand, the absorption of calcium can be affected if taken together with steroid and HCTZ
- Certain compounds in plants – sweet potato, bean (e.g., oxalic acid, phytic acid) can decrease calcium absorption by forming indigestible salts with calcium, decreasing its absorption.
Broccoli, kale, and cabbage do not contain these compounds - Net absorption of dietary calcium is also reduced to a small extent by intakes of caffeine.
