Comparison guide
Which calcium should you take?
Food-first is the real answer for calcium — supplements are for closing a measured gap. Among supplements, the boring forms win: the exotic ones charge more for the same element wrapped in a story.
The options, compared
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Calcium | Moderate evidence | Most people (carbonate, with meals) | Highest elemental calcium per pill and cheapest; needs stomach acid, so take with food. | View |
| Calcium Citrate | Moderate evidence | Older adults / acid reducers | Absorbs fine without stomach acid — the right pick with PPIs or after bariatric surgery. | View |
| Algae Calcium | Limited evidence | Label preference | 'Plant calcium' with trace minerals; the added-benefit trials are small and industry-run. | View |
| Coral Calcium | Limited evidence | Avoid | Just calcium carbonate from coral with legendary marketing claims — the FTC prosecuted the famous ones. | View |
Our verdict
Carbonate with meals for most; citrate if you're on acid blockers or older. Skip coral entirely, and remember the strongest calcium evidence is for diet plus vitamin D, not high-dose pills.