A nurse is evaluating a client with a history of kidney stones. Which dietary modification should the nurse recommend to prevent recurrence?

Choice A reason: Increasing oxalate-rich foods (e.g., spinach, nuts) promotes calcium oxalate stone formation, a common type of kidney stone. Oxalate binds calcium in the urine, increasing crystallization risk, so reducing these foods is recommended to prevent stone recurrence, making this an incorrect dietary modification. Choice B reason: Reducing fluid intake increases urine concentration, promoting stone formation by allowing minerals like calcium and uric acid to precipitate. High fluid intake (2–3 L/day) is essential to dilute urine and prevent stones, so this is an incorrect recommendation for kidney stone prevention. Choice C reason: Increasing citrus fruit consumption, such as lemons or oranges, provides citrate, which inhibits kidney stone formation by binding calcium and preventing crystallization. Citrate also alkalinizes urine, reducing uric acid stones, making this a key dietary strategy to prevent recurrence in clients with a history of stones. Choice D reason: Limiting carbohydrate intake is not directly related to kidney stone prevention. While high sugar intake may increase urinary calcium, general carbohydrate restriction is less critical than hydration or citrate intake, which directly influence urine chemistry to reduce stone formation risk.