Kidney stones are largely preventable through a combination of hydration, dietary changes, and in some cases medication. About half of people who get a kidney stone will form another one within five to ten years, but the right habits can dramatically cut that risk. The most important single step is drinking enough fluid to produce at least 2.5 liters of urine per day.
Drink Enough to Dilute Your Urine
Fluid intake is the foundation of kidney stone prevention, regardless of what type of stone you’ve had. The goal is 8 to 12 cups of liquid per day (roughly 2 to 3 quarts), which should produce at least 2.5 liters of urine daily. At that volume, the minerals and salts that form stones stay diluted enough that they’re less likely to crystallize.
Water is the best choice, but other fluids count too. A practical way to check: your urine should be pale yellow or nearly clear throughout the day. If it’s dark or concentrated, especially in hot weather or after exercise, you’re not drinking enough. People who live in warm climates or sweat heavily during work or sports need more than the baseline recommendation.
Get Calcium From Food, Not Supplements
This surprises most people, since calcium oxalate is the most common type of kidney stone. But dietary calcium actually helps prevent stones. When you eat calcium-rich foods, the calcium binds to oxalate in your digestive tract before it ever reaches your kidneys. That means less oxalate gets absorbed into your bloodstream and filtered into your urine, where it could form stones.
The American Urological Association recommends 1,000 to 1,200 mg of dietary calcium per day for people with calcium stones. Good sources include milk, yogurt, cheese, and fortified foods. The key word here is “dietary.” Calcium supplements and calcium-containing antacids can actually increase stone risk, likely because they’re taken separately from meals and don’t bind oxalate as effectively in the gut. If you need a supplement for bone health, taking it with a meal that contains oxalate helps.
Cut Back on Sodium
Sodium has a direct effect on stone formation that most people don’t realize. When you eat a lot of salt, your kidneys excrete more calcium into your urine. That extra urinary calcium provides the raw material for calcium-based stones. The recommended limit for stone formers is no more than 2,300 milligrams of sodium per day, which is about one teaspoon of table salt.
Most excess sodium comes from processed and restaurant foods rather than the salt shaker. Canned soups, deli meats, frozen meals, chips, and fast food are the biggest contributors. Reading nutrition labels and cooking more at home are the most practical ways to get sodium under control. For many stone formers, reducing sodium is just as important as increasing fluid intake.
Limit High-Oxalate Foods
If you’ve had calcium oxalate stones (the most common type), reducing oxalate-rich foods can help. The foods most often flagged include spinach, rhubarb, wheat bran, tree nuts, and peanuts. You don’t need to eliminate these entirely, but eating large amounts regularly raises the oxalate concentration in your urine.
A practical strategy is to pair high-oxalate foods with calcium-rich foods at the same meal. Eating spinach in a salad with cheese, for example, lets the calcium bind oxalate in your gut before it reaches your kidneys. This combination approach is more realistic than trying to avoid every oxalate-containing food.
Watch Your Animal Protein Intake
Eating too much animal protein, including beef, poultry, pork, eggs, and fish, raises your risk in multiple ways. These foods are rich in sulfur-containing amino acids that create an acid load in your body. Your kidneys respond by pulling calcium from your bones to buffer the acid, which increases calcium in your urine. At the same time, the acid load lowers your urine’s citrate levels (citrate is a natural stone inhibitor) and drops urine pH, creating conditions favorable for both calcium and uric acid stones.
Animal proteins also contain purines, which your body breaks down into uric acid. Excess uric acid in the urine is the direct cause of uric acid stones, the second most common type. Stone formers are advised to limit all animal proteins, including fish. You don’t need to go vegetarian, but making plant-based proteins a bigger part of your diet helps. Beans, lentils, and tofu are good alternatives for some meals.
Add Citrus to Your Diet
Citrate is a natural substance in urine that inhibits stone formation by binding to calcium and preventing crystals from growing. People with low urinary citrate are at higher risk for stones. One of the simplest ways to boost citrate is through citrus fruits and juices.
Orange juice appears to have a stronger protective effect than lemon juice, with about 200 mL (roughly 7 ounces) daily being the amount used in studies. Lemonade made with real lemon juice mixed into water is another popular option, though research suggests it has a smaller effect. The important thing is choosing real citrus juice rather than citrus-flavored drinks, which often contain little actual juice. Be mindful of the sugar content in store-bought juices, since added sugars can increase stone risk through other pathways.
Be Cautious With Vitamin C Supplements
Your body converts excess vitamin C into oxalate, which is then excreted through your kidneys. The daily requirement for vitamin C is only 90 mg for men and 75 mg for women, amounts easily met through fruits and vegetables. Many supplements deliver ten times that amount or more, and high-dose vitamin C has been linked to increased kidney stone risk, particularly in men.
If you have a history of calcium oxalate stones, avoid high-dose vitamin C supplements. Getting your vitamin C from food (oranges, bell peppers, strawberries, broccoli) doesn’t carry the same risk because the amounts are much lower and come with other beneficial compounds.
Prevention by Stone Type
Not all kidney stones are the same, and knowing your stone type (usually determined by analyzing a stone you’ve passed or had removed) helps you target prevention more effectively.
Calcium Oxalate Stones
These are the most common, making up roughly 80% of all kidney stones. The core strategy combines high fluid intake, adequate dietary calcium (1,000 to 1,200 mg daily), sodium restriction, moderate animal protein, and limiting high-oxalate foods. Pairing calcium with oxalate at meals is particularly effective for this type.
Uric Acid Stones
These form when urine is too acidic and contains too much uric acid. Limiting animal protein is the primary dietary intervention, since meat, poultry, and fish are the main dietary sources of purines. Keeping urine less acidic through citrate-rich foods or prescribed potassium citrate can also prevent uric acid crystals from forming.
Cystine Stones
These are caused by a genetic condition called cystinuria and are much rarer. Aggressive hydration and potassium citrate are typically the first-line approaches, with additional medications available if dietary changes aren’t enough.
When Medication Becomes Necessary
If you’ve had recurrent stones and dietary changes alone haven’t worked, your doctor may prescribe medication based on what’s showing up in your urine tests.
Potassium citrate is one of the most commonly prescribed options. It raises citrate levels in urine and can also make urine less acidic, which helps prevent both calcium and uric acid stones. It’s typically taken twice daily in tablet form.
For people whose urine contains persistently high calcium despite sodium restriction and adequate dietary calcium, a type of diuretic called a thiazide may be prescribed. These medications reduce the amount of calcium your kidneys release into urine. Long-acting versions are generally preferred because they work more consistently throughout the day.
Medication is usually considered a second-line strategy after dietary and fluid changes have been given a real trial. A 24-hour urine collection test helps your doctor identify the specific imbalances driving your stones, so treatment can be tailored rather than generic. If you’ve had more than one stone, this metabolic workup is worth pursuing.