Answer to Question 1
Calcium oxalate stones require limiting intake of foods high in oxalates: spinach, rhubarb, beets, nuts and peanuts, chocolate, tea, wheat germ, wheat bran, soy beans and soy milk, dry beans, and sweet potatoes. Avoid megadoses of vitamin C supplements, pyridoxine, thiamine, and magnesium, as they raise urinary oxalate concentrations.
Uric acid stones require a purine-restricted diet that limits red meat, particularly organ meats, anchovies, sardines, and meat extracts. A diet of no more than 100 g of protein per day is advised, and alcohol intake is limited.
Cystine stones form as a result of an inherited disorder of amino acid metabolism. Dietary restrictions limit the foods with the amino acid methionine, or an alkaline-ash diet is recommended; increased fluids are encouraged.
Struvite stones are treated with a low-phosphorus diet.
Answer to Question 2
B
