Use of Over-the-Counter Calcium Carbonate: Excess can be Harmful

Calcium carbonate, available over the counter, is commonly used by patients. Its excessive use has led to resurgence of milk-alkali syndrome (MAS). Clinical features of MAS are non-specific and can easily be missed. Undetected MAS can result in progressive renal impairment, which can even be permanent. Therefore, it is important to obtain detailed information about the use of medications including over-the-counter medications. Here, we present a case of a 61-year-old man who developed acute renal failure on top of chronic kidney disease as a result of the delayed diagnosis of MAS.