| Calcium Carbonate | Inorganic Salt | ❌ No | ~40% | Moderate | Low (Needs Acid) | Most common form; best taken with meals |
| Calcium Citrate | Organic Salt | ❌ No | ~21% | High | Excellent | Good for elderly & those with low stomach acid |
| Calcium Gluconate | Inorganic Salt | ❌ No | ~9% | Low | Good | Often used in IV or emergency formulations |
| Calcium Lactate | Organic Salt | ❌ No | ~13% | Moderate | Good | Used in food fortification and supplements |
| Calcium Phosphate | Inorganic Salt | ❌ No | ~39% | Moderate | Moderate | Supports both calcium and phosphorus intake |
| Calcium Citrate Malate | Chelated (Blended) | ✅ Yes | ~26% | Very High | Excellent | Used in premium supplements & juices |
| Calcium Malate | Chelated | ✅ Yes | ~15–25% | High | Very Good | Supports bone and muscle metabolism |
| Calcium Orotate | Chelated (Orotic Acid) | ✅ Yes | ~10–20% | High | Very Good | Cell-level absorption; premium bone support |
| MCHA (Hydroxyapatite) | Natural Bone Matrix | ⚠️ Complex | ~20–25% | High | Very Good | Contains bone-building minerals & collagen |
| Coral Calcium | Natural Mineral Source | ❌ No | Varies | Moderate | Moderate | Often marketed with trace minerals |
