Can I use Tums (antacids) as a calcium supplement?

Can You Use Tums as a Calcium Supplement?

Yes, Tums (calcium carbonate) is an effective and widely accepted calcium supplement that provides 40% elemental calcium by weight, making it one of the most cost-effective options available. 1

Understanding Tums as Calcium Supplementation

Tums products contain calcium carbonate, which is explicitly recognized in clinical guidelines as a legitimate calcium supplement formulation. 1 The various Tums formulations provide different amounts of elemental calcium:

• Tums EX (extra strength): 750 mg calcium carbonate = 300 mg elemental calcium 1
• Tums Ultra: 1,000 mg calcium carbonate = 400 mg elemental calcium 1
• Tums 500: 500 mg elemental calcium per dose 1

To meet a typical supplementation goal of 1,500 mg elemental calcium daily, you would need 5 tablets of Tums EX or 3.75 tablets of Tums Ultra. 1

How to Take Tums for Calcium Supplementation

Take Tums with meals to ensure optimal absorption, as calcium carbonate requires gastric acid for proper dissolution and absorption. 1, 2

Dosing Strategy

• Divide doses into increments of 500 mg elemental calcium or less to maximize absorption and minimize gastrointestinal side effects 1, 2
• Taking more than 500 mg of elemental calcium at once reduces absorption efficiency 1, 2
• Space doses throughout the day with meals 1

Important Caveats and Considerations

When Tums May NOT Be the Best Choice

If you take acid-reducing medications (proton pump inhibitors or H2 blockers) or have achlorhydria, calcium citrate is preferred over calcium carbonate because it doesn't require stomach acid for absorption. 3, 2, 4

Common Side Effects

Calcium carbonate is more likely than other calcium forms to cause:

• Constipation 1, 3
• Bloating 1, 3
• Gastrointestinal discomfort 2

If these symptoms occur, consider switching to calcium citrate, which provides 21% elemental calcium but causes fewer GI symptoms. 1, 3

Safety Limits

Do not exceed 2,000-2,500 mg of total elemental calcium per day from all sources (diet plus supplements) to avoid increased risk of kidney stones and potential cardiovascular concerns. 1, 5, 6

Practical Algorithm for Calcium Supplementation with Tums

1. Calculate your dietary calcium intake: Most adults get ~300 mg from non-dairy sources plus additional amounts from dairy products 1

2. Determine supplementation need: If dietary intake is below 1,000-1,200 mg daily (depending on age/sex), supplementation is appropriate 1

3. Choose appropriate formulation:

   • Normal gastric acid + no reflux: Tums (calcium carbonate) is appropriate and cost-effective 1, 5
   • Taking acid reducers or have reflux: Use calcium citrate instead 3, 2

4. Dose appropriately: Take ≤500 mg elemental calcium per dose, with meals, 2-3 times daily as needed 1

5. Monitor for side effects: If constipation or bloating develops, reduce dose or switch to calcium citrate 1, 3

Bottom Line

Tums is a legitimate, guideline-supported calcium supplement that is safe and effective when taken correctly with meals in divided doses. 1, 5 The key is ensuring you have adequate stomach acid for absorption—if you're on acid-blocking medications, choose calcium citrate instead. 3, 2