1. Aim to Drink at Least 8 Glasses of Water a Day
One of the best ways to prevent all four types of kidney stones is to stay hydrated. By drinking more fluids, you dilute your urine and reduce the concentration of compounds (called solutes) that can bind together into crystals. Although there is no hard-and-fast rule as to exactly how much fluid you need—you may need more if you exercise or have a larger body mass—many experts recommend drinking at least 2 liters of fluids per day. That translates roughly to eight 8-ounce glasses per day. Up to 3 liters a day may be necessary if you have a history of kidney stones. Water is always best, but broth, apple juice, tea, low-fat milk, and nonacidic vegetable or fruit juices are also good.
2. Reduce Your Sodium Intake
Calcium stones can form when you excrete excessive amounts of calcium through your urine. These stones include calcium oxalate stones, which account for roughly 70% of all kidney stones, and the less common calcium phosphate stones. Both calcium and sodium are electrolytes, which are charged minerals in the blood. To reduce calcium stones, limit your sodium intake to 2,300 milligrams (mg) daily from all sources. A high sodium level, obtained mainly from salt intake, alters the electrolyte balance in your blood and releases more calcium into your urine. If you have a history of kidney stones, you may be advised to cut back to no more than 1,500 mg of sodium per day. Start by reducing your intake of sodium-rich foods, such as processed meats, instant soups, and packaged sauces. Replace them with low-sodium versions. You should also avoid adding salt to food and instead season it with fresh herbs, spices, or lemon juice.
3. Watch Your Intake of Oxalate-Rich Foods
Oxalates, also known as oxalic acid, are naturally occurring compounds in plants. They have no known function in the human body. When the foods you eat release too many oxalates, they can bind to calcium in your urine and form stones. If you have a history of calcium oxalate stones, you should try to follow a low-oxalate diet. Foods to avoid include:
- Peanuts
- Rhubarb
- Spinach
- Beets
- Swiss chard
- Chocolate
- Sweet potatoes
Oxalates are generally safe for people with no history of kidney stones, and the benefits of eating oxalate-rich vegetables and fruits generally outweigh any possible risks.
4. Eat Calcium-Rich Foods
Eating calcium-rich foods may seem counterintuitive, as calcium is a common component of kidney stones. However, a diet rich in calcium may actually help reduce the risk of kidney stones by increasing the amount of calcium in your urine and reducing the concentration of oxalates. Foods high in calcium include:
- Dairy products
- Leafy greens
- Fortified cereals
- Tofu
- Almonds
- Broccoli
- Kale
- Collard greens
10. Try a Citrate Supplement
Potassium citrate supplements, available over the counter, can make your urine less acidic. By doing so, they can help reduce the risk of calcium oxalate, cystine, and uric acid stones (but not calcium phosphate or struvite stones, which form in alkaline urine). Experts recommend taking 9 mg of potassium per day, divided into three doses and taken within 30 minutes of a meal or a bedtime snack. Sodium citrate supplements should be avoided because sodium can increase calcium excretion and negate the benefit. Potassium citrate supplements should be taken under the guidance of a healthcare provider and not as a substitute for medical treatment. If they are taken inappropriately, side effects such as muscle weakness, irregular heartbeats, and stomach ulcers can occur.
11. Check That Your Medications Are Safe
Many prescription and over-the-counter drugs can contribute to the formation of kidney stones. Though some may need to be avoided or substituted, others may be essential to your health and should not be stopped without an OK from your healthcare provider. Advise your provider if you take any of the following and are concerned about your risk of kidney stones or kidney stone recurrence:
- Loop diuretics like Lasix (furosemide), Bumex (bumetanide), Edecrin (ethacrynic acid), and Soaanz (torsemide)
- Glucocorticoids like prednisone, methylprednisolone, cortisone, betamethasone, and dexamethasone
- Anticonvulsants like Topamax (topiramate) and Zonegren (zonisamide)
- HIV drugs like indinavir, atazanavir, nelfinavir, tenofovir disoproxil fumarate (TDF), raltegravir, and efavirenz
- Antibiotics like sulfadiazine, sulfamethoxazole, ciprofloxacin, amoxicillin, ampicillin, and ceftriaxone
- Gout medications like Zyloric (allopurinol) and Probalan (probenecid)
- Azulfidine (sulfasalazine)
- Cozaar (losartan)
- Gaviscon (magnesium trisilicate)
- Mucinex (guaifenesin)
The overuse of laxatives can also contribute to the formation of uric acid stones.
Summary
Depending on your risk of kidney stones or the type of stone you’ve had in the past, there are ways to reduce your risk. These include cutting back on salt, animal protein, sugar, oxalate, and carbonated beverages and increasing your intake of calcium-rich foods. It is equally important to drink plenty of water to keep your urine diluted and to lose weight if you are overweight. You should also avoid vitamin C supplements and speak with your healthcare provider about potassium citrate supplements if you are at risk of calcium oxalate or uric acid stones.
FAQs
Q: How can I reduce my risk of kidney stones?
A: You can reduce your risk of kidney stones by cutting back on salt, animal protein, sugar, oxalate, and carbonated beverages and increasing your intake of calcium-rich foods.
Q: How much water should I drink per day?
A: You should aim to drink at least 8 glasses of water per day, but the exact amount may vary depending on your individual needs.
Q: Can I take vitamin C supplements to prevent kidney stones?
A: No, you should avoid taking vitamin C supplements if you are at risk of kidney stones.
Q: Can I take potassium citrate supplements to prevent kidney stones?
A: Yes, potassium citrate supplements can help reduce the risk of calcium oxalate, cystine, and uric acid stones. However, you should take them under the guidance of a healthcare provider and not as a substitute for medical treatment.
