Interaction Between Iron Supplements and Calcium

Understanding the Supplements

• Calcium carbonate provides 40% elemental calcium content but is more likely to cause gastrointestinal side effects like constipation, bloating, and reflux symptoms compared to other calcium supplements 1

Clinical Implications

• This simplifies medication regimens and may improve adherence, as separation of calcium and iron supplements would otherwise necessitate multiple daily administrations 2

Recommendations for Clinical Practice

• For patients with GERD or gastrointestinal sensitivity, consider calcium citrate instead of calcium carbonate, as it causes fewer gastrointestinal side effects 1
• Be aware that excessive calcium supplementation (above 2,000-2,500 mg per day) may increase risk of kidney stones and potentially cardiovascular events 1
• Avoid recommending calcium carbonate to patients with significant reflux symptoms, as it may exacerbate their condition 1