Regarding calcium intake for kidney stone prevention, which statement is correct?

• A. Restrict calcium intake
• B. Avoid dairy products entirely
• C. Maintain normal calcium intake
• D. Calcium supplements are always unnecessary

Answer: (C)

Calcium in the diet helps prevent calcium oxalate stones because it binds oxalate in the gut, forming insoluble calcium oxalate that is excreted rather than absorbed. This lowers the amount of oxalate that reaches the kidneys and reduces stone risk. Therefore, keeping a normal calcium intake, mostly from foods, is the best approach for prevention. Restricting calcium or avoiding dairy can actually increase absorption of oxalate, raising urinary oxalate levels and the chance of stone formation. Calcium supplements aren’t automatically unnecessary; they may be appropriate if dietary calcium is inadequate, but they should be used under medical guidance, typically with meals, rather than assumed to be risk-free. The key takeaway is to maintain normal dietary calcium rather than cutting it back or relying on supplements without advice.