Calcium oxalate stones are kidney stones formed from the mineral calcium and the organic molecule oxalate. Most individuals who have kidney stones form stones of this type. You can prevent or diminish the occurrence of calcium oxalate stones by eliminating or limiting foods and liquids in your diet that tend to support stone formation.
Understanding Stone Formation
When you eat, your body takes the nutrient content from your food and passes a number of waste products through your bloodstream to your kidneys, according to the National Kidney and Urologic Diseases Information Clearinghouse. Your kidneys then eliminate these waste products through your urine. Kidney stones form when waste products from certain foods crystallize in your urine rather than remaining diluted. Stones made from calcium and oxalate usually form when your urine has a low pH, which indicates high levels of acidity.
Oxalate-Containing Foods
Your body naturally makes some oxalate, the NKUDIC notes. However, the addition of high-oxalate foods to your diet can significantly increase your risks for calcium oxalate stone formation. While a variety of foods contain oxalate, only nuts, spinach, wheat bran and rhubarb have been shown to directly increase oxalate output in your urine. You can reduce your risks either by avoiding these foods entirely or by also eating foods or supplements that contain calcium. While this may seem counterintuitive, dietary calcium chemically binds oxalate and stops it from passing to your urine from your digestive tract.
Sodium
The sodium content in table salt can help trigger the formation of calcium oxalate stones by increasing the amount of calcium your body excretes into your urine, the NKUDIC reports. On average, Americans consume far more salt than necessary, and reducing your salt intake may reduce your risks for stone formation or recurrence. Foods that commonly contain high amounts of salt or sodium include fast foods, canned vegetables and soups, hot dogs and luncheon meats. In addition to salt, sodium may appear in your food in forms that include sodium nitrate, sodium nitrite, baking powder, sodium bicarbonate, disodium phosphate and monosodium glutamate, or MSG. To avoid unintended sodium consumption, check packaged food labels for these substances.
Additional Components
If you eat a high-protein diet, you can increase the levels of both calcium and oxalate in your urine, according to the University of Michigan Health System. You can avoid consuming too much protein by limiting yourself to two servings of dairy and 5 oz. of meat, fish or poultry per day. You can also decrease your calcium oxalate risks by increasing your intake of caffeine-free, non-alcoholic liquids to 8 cups per day and avoiding dark colas and grapefruit juice. In addition, avoid the consumption of vitamin C or D supplements, since they can also increase oxalate excretion.
Considerations
The NKUDIC lists additional factors in kidney stone formation that include your weight, genetic predisposition and local environment. In some cases, individuals on a kidney stone diet must also take medication to control stone formation. Additional types of kidney stones include cystine stones, struvite stones and uric acid stones. Consult your doctor for more information.
