A nurse is caring for a client who has chronic kidney disease (CKD) and states she has heartburn. The provider prescribes aluminum hydroxide. The client asks, "Why can't I just take the antacid magaldrate my husband has at home?" The nurse explains to the client that aluminum hydroxide is the preferred antacid because it lowers which of the following?

Choice A reason: Aluminum hydroxide does not significantly lower serum calcium levels. In fact, some antacids may contain calcium carbonate, which can increase calcium levels. This is not the therapeutic target in CKD management. Choice B reason: Serum potassium levels are managed through dietary restrictions, medications like sodium polystyrene sulfonate, and dialysis. Aluminum hydroxide does not directly affect potassium levels. Choice C reason: Aluminum hydroxide binds dietary phosphorus in the gastrointestinal tract, preventing its absorption and thereby lowering serum phosphorus levels. This is crucial in CKD management, as hyperphosphatemia contributes to secondary hyperparathyroidism and bone disease. Choice D reason: Magnesium-containing antacids are generally avoided in CKD due to the risk of hypermagnesemia. Aluminum hydroxide does not lower magnesium levels and is preferred specifically for its phosphate-binding properties.