A nurse is providing dietary teaching to a client who has a history of recurring calcium oxalate kidney stones. Which of the following instructions should the nurse include in the teaching?

A. Take 3,000 mg of vitamin C daily: High doses of vitamin C are not recommended because excess vitamin C is metabolized into oxalate, which can increase the risk of calcium oxalate stone formation. This practice would worsen rather than prevent recurrence. B. Eat 12 oz of animal protein daily: Excessive animal protein intake increases calcium and uric acid excretion while lowering urinary citrate, which promotes stone formation. Clients with calcium oxalate stones are advised to limit animal protein, not increase it. C. Restrict calcium intake to one serving per day: Severe restriction of dietary calcium is not recommended. Adequate calcium intake is necessary because calcium binds oxalate in the gut, preventing absorption. Restricting calcium can increase oxalate absorption and stone risk. D. Drink 3 L of fluid every day: Increasing fluid intake dilutes urine, reduces urinary supersaturation, and promotes passage of crystals before they aggregate into stones. Maintaining a high fluid intake is the most effective and recommended measure to prevent recurrence of calcium oxalate stones.