Calcium Carbonate Chews Dosing Frequency
For adults and children 12 years and older using calcium carbonate chews as an antacid, take 1-2 chewable tablets every 2-4 hours as needed, not exceeding 5 tablets in 24 hours. 1
Antacid Use (Symptom Relief)
When using calcium carbonate chews specifically for heartburn or acid reflux relief:
- Dosing interval: Every 2-4 hours as needed for symptom control 1
- Maximum daily limit: Do not exceed 5 chewable tablets in any 24-hour period 1
- Duration restriction: Do not use maximum dosage for more than 2 weeks without physician supervision 1
- Pediatric considerations: Children under 12 years should consult a doctor before use 1
The FDA labeling is clear that this dosing applies to over-the-counter antacid use, where calcium carbonate provides rapid symptom relief by neutralizing esophageal acid within 15-30 minutes 2.
Calcium Supplementation (Nutritional Support)
If you are taking calcium carbonate chews for calcium supplementation rather than antacid purposes, the dosing strategy differs significantly:
Optimal Absorption Strategy
- Divide doses: Take no more than 500-600 mg of elemental calcium per administration to maximize absorption 3
- Timing: Calcium carbonate must be taken with meals since gastric acid is required for optimal absorption 4, 3
- Frequency: Typically 2-3 times daily with meals to reach daily calcium requirements 5
Daily Calcium Requirements
The total daily elemental calcium intake (diet plus supplements) should meet age-specific targets 3:
- Adults 19-50 years and men 19-70 years: 1000 mg/day total 3
- Women over 50 years and men over 70 years: 1200 mg/day total 3
- Upper safety limit: 2000-2500 mg/day (do not exceed) 3
Practical Calculation
Since calcium carbonate contains 40% elemental calcium 4, 3:
- A 500 mg calcium carbonate tablet provides 200 mg elemental calcium
- A 1250 mg calcium carbonate tablet provides 500 mg elemental calcium
- To supplement 1000 mg elemental calcium daily would require 2500 mg calcium carbonate, divided into 2-3 doses with meals
Important Caveats
Common side effects: Constipation and abdominal bloating are frequent with calcium carbonate 4, 1
Drug interactions: Space calcium supplements at least 2 hours apart from iron supplements, as calcium inhibits iron absorption 3
Special populations: Patients with chronic kidney disease should not exceed 2000 mg/day total calcium intake due to hypercalcemia risk 3
Dietary sources preferred: Calcium-rich foods (dairy products, fortified foods) should always be maximized before considering supplements 4, 3
The key distinction is whether you're using calcium carbonate chews for acute symptom relief (every 2-4 hours as needed) versus nutritional supplementation (divided doses with meals, 2-3 times daily). The FDA labeling addresses only the antacid indication, while nutritional supplementation follows different evidence-based guidelines focused on absorption optimization and meeting daily requirements.