Calcium Supplements
Types of Calcium Supplements
- The American College of Cardiology is not mentioned, however, the New England Journal of Medicine recommends calcium carbonate as it provides the highest elemental calcium content at 40% 1, 2
- Calcium carbonate is the most cost-effective and widely available option 1, 3
- Calcium carbonate should be taken with meals since gastric acidity is required for optimal absorption 2, 3
- Calcium citrate contains 21% elemental calcium and can be taken with or without food as absorption is not dependent on gastric acidity 1, 2
- The Institute of Medicine is not the author, however the New England Journal of Medicine states calcium citrate is preferred for patients with gastrointestinal issues, GERD, or those taking acid-reducing medications, although this is also mentioned in 4
- Calcium lactate and calcium gluconate are less commonly used due to lower elemental calcium content 1
Dosing Considerations
- The maximum dose of elemental calcium that should be taken at one time is 500 mg to optimize absorption 6
- If daily supplementation exceeds 500 mg of elemental calcium, divided doses are recommended to improve absorption and minimize gastrointestinal side effects 1, 2
- Calcium supplements should ideally complement dietary calcium intake rather than replace it completely 4
- The Institute of Medicine recommends different calcium intake levels based on age and sex, with most adults needing 1000-1200 mg daily 2, 7
Absorption Considerations
- Calcium carbonate requires stomach acid for optimal absorption and should be taken with meals 2
- Calcium citrate absorption is less dependent on gastric acidity, making it suitable for elderly patients or those taking acid-reducing medications, although this is also mentioned in 4
- Some evidence suggests that calcium from certain dietary sources like broccoli and kale may be better absorbed than from supplements 2, 3
Special Populations
- For pregnant women, calcium carbonate is often the most cost-effective choice, though absorption considerations remain important 5, 6