Which mineral interacts with aspirin and calcium carbonate?

• A. Calcium
• B. Magnesium
• C. Iron
• D. Zinc

Answer: (A)

When thinking about mineral-drug interactions, the gut is the key arena. Some minerals can bind to other substances in the intestinal lumen or compete for absorption, altering how well each nutrient or medication works.

Iron is the mineral that best fits with both aspirin and calcium carbonate. Calcium carbonate is a calcium supplement, and calcium can bind to iron in the gut, forming insoluble complexes and reducing non-heme iron absorption. That means taking iron supplements together with calcium carbonate commonly lowers iron uptake. Aspirin, as an NSAID, irritates the stomach lining and can increase the risk of gastrointestinal bleeding. If someone is relying on iron to treat or prevent deficiency, concurrent aspirin use can worsen GI upset or blood loss, making iron status more of a concern. So iron has a twofold relevance: its absorption is reduced by calcium carbonate, and its GI status can be impacted by aspirin.

The other minerals don’t have as direct or clinically significant a interaction pattern with both aspirin and calcium carbonate in typical practice. For example, while magnesium or zinc can influence iron absorption to some extent, the clearest and most well-known interaction publicly taught in nutrition and pharmacology contexts is iron’s reduced absorption with calcium, plus the GI considerations with aspirin. To minimize problems, time iron and calcium supplements a few hours apart and consider vitamin C to aid iron absorption when appropriate.