Dietary Management of Urolithiasis (AKA Kidney Stones)

Kidney stones, also called Urolithiasis, can be reduced through diet modification and medical treatment. Diet modifications usually follow surgical treatment for kidney stones. Diet can be modified to help prevent calcium-containing stones, which are the most common type. Even though kidney stones are typically calcium-containing, new research shows that drinking milk may actually decrease the absorption of oxalate, a compound in some plant foods that can form calcium oxalate stones. Therefore, drinking milk may reduce the risk for kidney stone formation. It is important to go over lab results with your doctor to determine the intestinal absorption of calcium. This will indicate whether or not there is normal absorption of calcium; if so, then calcium intake can be around 1,000 mg/day; if not, then calcium intake will need to be compared with an individual’s health history to weigh the benefit of reducing calcium in the diet. Completing a diet history with a Registered Dietitian is a good start to make adjustments pertinent to an individual’s diet plus increasing fluid intake. The following are general guidelines to decrease the calcium-containing stones from forming.

Increasing fluid intake can prevent any type of stone formation. Other culprits include excessive amounts of sodium, oxalate and protein which increase the risk of future stone formation. Traditional fluid intake recommendations are approximately 3 quarts of fluid per day taken throughout the day. At least half of that should be from water. Protein should be reduced to a moderate amount of about 12-14% of calories. The usual recommendation for a general diet without protein reduction is 15-20%. Most Americans consume three times the amount of protein per day that is recommended. Increase the amount of vegetable protein and decrease the amount of animal protein. Animal protein can be high in purines which increases the risk of kidney stone formation. Reducing dietary intake of sodium and oxalate prevents calcium salts and oxalate crystals from saturating the urine, which present a risk for kidney stone formation.

The following chart is helpful for making appropriate daily food choices to decrease risk for kidney stone formation. I have left off calcium containing foods as that is something that should be conferred with a doctor. Check with your doctor and a Registered Dietitian before making any dietary changes as they can assess lab results and health history to check for any contraindications. A Registered Dietitian can assist in a long-term healthy eating pattern incorporating the necessary diet modifications.