There are a lot of calcium supplement choices out there from algae calcium that comes from ocean to calcium phosphate. It can get to be a bit mind boggling. Here are the four most common calcium types and a bit of information on each to help you and your doctor decide what might be best for you.
Carbonate (Calcium Carbonate)
- The most popular calcium on the market
- 40% of calcium carbonate is pure elemental calcium
- It is absorbed best when taken with food (even just some crackers, not necessarily a meal)
- Carbonate is relatively alkaline (not acidic) on the pH scale
Citrate (Calcium Citrate)
- The second most popular calcium on the market
- 21% of calcium citrate is pure elemental calcium
- No need to take calcium with food
Gluconate (Calcium Gluconate)
- Gluconate is the kind of calcium commonly used when given by intravenous infusion
- 9% of calcium gluconate is elemental calcium
Calcium Phosphate
- 38% of calcium phosphate is elemental
- Calcium phosphate can be taken with or without food
- Is not absorb as well as carbonate or citrate
- Because it is a phosphate, it might not be ideal for patients with certain medical conditions (like hypoparathyroidism)
There are other types of calcium that are less commonly used like algae calcium, bone meal, calcium chloride, coral calcium, calcium lactate, and oyster shell calcium. Whatever the type of calcium, try not to take more than 500 mg at a time and to talk to your doctor about other medications that may be affected by your calcium.