Your doctor has ordered a diet to help you decrease the chances of forming calcium oxalate kidney stones. Oxalate is a compound that is naturally present in many foods. The following six factors increase the risk of forming calcium oxalate stones.
1. The amount of oxalate in certain foods.
Although many foods contain oxalate, only nine foods are known to increase oxalate in the urine and kidney stone formation. They are: beets, spinach, rhubarb, strawberries, nuts, chocolate, tea, wheat bran, and all dry beans (fresh, canned, or cooked), excluding lima and green beans. It is best to avoid these foods.
2. The amount of calcium in your diet.
Low amounts of calcium in your diet will increase your chances of forming calcium oxalate kidney stones. You need calcium in your diet to bind oxalate in the intestines. This helps reduce the amount of oxalate being absorbed by your body, so stones are less likely to form. Consuming a moderate amount of calcium every day (2 to 3 servings) from dairy foods or other calcium-rich foods is recommended. If you take a calcium supplement, calcium citrate is the preferred form.
3. The vitamin C content of your diet.
Oxalate is an end product of Vitamin C (ascorbic acid) metabolism. Large doses of Vitamin C may increase the amount of oxalate in your urine, increasing the risk of kidney stone formation. If you are taking a supplement, do not take more than 500 mg of Vitamin C daily.
4. The amount of fluids in your diet.
It is very important to drink plenty of liquids. Your goal should be 10-12 glasses a day. At least 5-6 glasses should be water. You may also want to consider drinking lemonade. Research suggests that lemonade may be helpful in reducing the risk of calcium oxalate stone formation.
5. The amount of protein in your diet.
Eating large amounts of protein may increase the risk of kidney stone formation. Your daily protein needs can usually be met with 2-3 servings a day, or 4 to 6 ounces.
6. The amount of sodium in your diet.
Reduce the amount of sodium in your diet to 2-3 grams per day. Limit eating processed foods such as hot dogs, deli meats, sausage, canned products, dry soup mixes, sauerkraut, pickles, and various convenience mixes.