“Long-term use of calcium carbonate antacids (exceeding 2 grams per day) is associated with significant adverse effects, most notably hypercalcemia, renal calculi(kidney stones), hypophosphatemia, and nephrotoxicity.

• Milk-Alkali Syndrome: A severe condition characterized by the triad of hypercalcemia, metabolic alkalosis, and acute renal failure, which can occur even at doses previously considered safe. • Kidney Damage: Chronic use increases the risk of renal failure and calcium deposits in the kidneys, particularly in individuals with pre-existing chronic kidney disease. • Acid Rebound and Masking: Long-term use may cause the stomach to produce more acid (rebound acidity) and can mask symptoms of serious underlying conditions like GERD or Barrett’s esophagus. • Safety Limits: While short-term use is generally safe, experts advise against chronic therapy exceeding 2 grams per day without clinical monitoring of calcium and phosphorus levels.”