How Can Kidney Stone Formation Be Prevented?

Brief Answer:
Hello and welcome to HCM

Detailed Answer:
A truly specific diet could be tailored more accurately if I knew which type of stones you are prone to.

Below you will find nutrition guidelines to avoid kidney stones from the Academy of Nutrition and Dietetics. I hope you find it useful:

Diet can influence the formation and growth of kidney stones. Using diet to prevent kidney stones may mean changing what you eat. Depending on your individual risk factors and on the type of kidney stones you form, you may be advised to make changes. Nutrition therapy, as with other forms of therapy, is prescribed individually according to you and your specific needs and risks.

Risk factors for kidney stones vary between individuals and can even change within an individual over time. You probably won’t need to follow everything on this handout.

Your risk factors for kidney stone formation and growth are:
___ High urine calcium ___ Low urine volume ___ Low calcium intake

___ High urine uric acid ___ Low urine magnesium ___ High salt intake

___ High urine oxalate ___ Low urine citrate ___ High calcium intake

___ High acid urine ___ Low fruit and vegetable intake ___ Acid load of diet is high

Your Nutrition Therapy Checklist

Therapies that apply to you are checked.
__xIncrease your urine volume by drinking more fluids (usually 2 liters of urine or more is the goal)

Drinking at least 3 liters (at least 3 quarts or 100 ounces) of fluids per day is the best way to lower your risk for forming new stones. You may have to drink more than this if you exercise heavily or are in hot weather for long periods of time.
Spread your fluid intake throughout the day and night. All drinks count toward your fluid intake, including water, fruit juice, coffee, tea, milk, soda, and lemonade.
Drink more low-sugar, low-calorie beverages so you do not get too many of your calories from beverages.

Drink beer, wine, and alcoholic spirits in moderation, if at all.

HERE’S A TIP—Divide your day into 3 parts. Plan to drink at least 32 ounces in each part of the day. This will get you close to at least 100 ounces of fluids for the day.

_x__ Reduce urine calcium by reducing your salt (sodium) intake

Reducing sodium (salt) intake is a powerful way to reduce urine calcium. Most diets contain too much sodium. This may increase the amount of calcium your kidneys let out into the urine. Believe it or not, only about 10% of our salt intake comes from the salt shaker! The rest comes mostly from processed and prepared foods.
The sodium in your 24-hour urine collection is a good estimate of your intake. Based on your urine, your intake appears to add to your urine calcium. The recommended amount of sodium is 1,500 milligrams per day. Most people get more than this even if they don’t use the salt shaker. Start reducing salt by just eating less than you do now. Choose “no salt added” or “low-salt” foods as much as possible. Particularly high-salt foods to limit include:

Cheese (all types)     Most frozen foods and meals     Salty, cured meats and deli meats
Hot dogs, bratwurst, and sausages     Canned soups and vegetables     Breads, bagels, rolls, and baked goods
Salty snacks (chips, pretzels)     Certain salad dressings     Certain breakfast cereals
Pickles and olives     Casseroles and other “mixed” foods     Pizza, lasagna
Canned and bottled pasta sauces     Certain condiments     Table salt and some spice blends

_x__ Reduce urine calcium by balancing your diet- If you have a diet high in dairy, it is not necessary to take extra calcium unless ordered by your doctor.

Balancing your diet for acid is important if your urine calcium is high. A high “acid load” diet may cause your bones to release more calcium into the bloodstream than they should. This can add to high urine calcium.

The foods causing the highest acid load are:

Cheese
Meats of all types
Fish and seafood
Poultry
Reduce the number of times you eat these foods in a week and eat smaller portions of these foods.

Foods in the grain group—breads, cereals, rice, and pasta—also add to the acid load of the diet, but not as much as cheese, meat, poultry, and fish. Fewer grain foods, or smaller portions, may help reduce urine calcium.

Milk and yogurt do not need to be restricted unless otherwise recommended.
Nearly all fruits and vegetables have the opposite effect of acid. Eating more of these will help balance your diet against the acidic effects of meats and cheese.

_x__ Reduce urine oxalate: 4 strategies
There are different ways to lower the amount of oxalate in your urine. How you do so will depend on why your urine oxalate levels are high. It is unlikely that all the strategies below apply to you. Those that are circled apply to you most.

A. Eat or drink something with about 300 milligrams of calcium at each meal and snack.

WHY? Calcium and oxalate bind in the digestive tract and get removed in the stool. Less oxalate is absorbed and available to the urine. Foods and beverages are best for including calcium; non-dairy sources are available for those who may be lactose intolerant or who otherwise avoid or limit dairy. Calcium supplements may be included, but you should not have more than 1,200 to 1,500 milligrams of calcium a day. (If you have short bowel or malabsorption, you may be advised to use more calcium.)

B. Eat fewer “high-oxalate” foods.

WHY? The more oxalate absorbed from your digestive tract, the more in your urine. High-oxalate foods to limit, if you eat them, are:
Spinach
Rhubarb
Beets
Potato chips
French fries
Nuts and nut butters

You do not need to cut out other healthy foods that provide some oxalate. In fact, oxalate is practically unavoidable, because most plant foods have some. Often a combination of calcium from foods or beverages with meals and fewer high-oxalate foods is required.

C. Stop taking vitamin C supplements.
WHY? When the body gets more vitamin C than it needs, some of the vitamin C breaks down into oxalate. The oxalate then goes to the kidneys and into the urine. You do not need to limit fruits and vegetables with vitamin C.

D. Increase the amount of oxalate-eating bacteria in your digestive tract.
WHY? If you’ve ever been on an antibiotic, especially recently, or if you’ve had part of your digestive tract removed, you are at special risk of not having enough good bacteria (also known as probiotics). Many different bacteria eat oxalate, which reduces the amount of oxalate that is absorbed and reduces oxalate in urine. Eating foods with live cultures, such as yogurt and kefir, may help, but you may need a large dose of probiotics. Start a daily probiotic supplement. Choose one with at least 3, preferably more, different strains of bacteria to increase the chance that some of them will lower the level of oxalate.
In certain cases, vitamin B-6 and/or fish oil supplements are recommended.

__x_ Reduce urine acidity (especially relevant for those who form uric acid or cystine stones)

Sometimes, only medication can address acidic urine effectively. But you can decrease the acidity of your urine by increasing your intake of fruits and vegetables, which provide potassium and other compounds that alkalinize your urine. You can also reduce the amount of foods you eat that contribute directly to acidity, and these include cheese, meats, fish, and poultry.

_x__ Reduce urine uric acid: 2 ways
All meats of all types, including poultry and fish, contribute to uric acid production in the body. You are advised to eat fewer of these foods within a week and/or to eat smaller portions. Organ meats, water fowl, game meats, and certain types of seafood (anchovies, sardines, herring) are especially high in purines. When purines are consumed, they increase uric acid levels. HERE ARE SOME TIPS FOR REDUCING PURINES:
Make 2 or more days a week “non-meat” days (you may use dairy and eat non-meat protein foods like beans).
Limit yourself to one serving per day of meat, fish, poultry or seafood.
Limit portion sizes of meat, fish, poultry, or seafood to no more than one-quarter of your plate (or 3 to 4 ounces by weight).
There are other potential contributors to high urine uric acid. If applicable and depending on your current intake, you may be advised to reduce your consumption of alcohol and/or of fructose, a carbohydrate found naturally in moderate amounts in fruits but used in large amounts in processed foods.

_x__ Increase urine citrate

If your citrate is very low, a medication may be prescribed to help increase it. Otherwise, and in addition to medication, eating more fruits and vegetables—at least 5 a day—and choosing beverages high in citric acid can increase your urine citrate. Pure lemon juice (not lemonade) and lime juice are very rich in citric acid. You may try using 2 ounces of lemon or lime juice diluted in water or other beverage twice daily. Beverages with citric acid in them include some diet sodas and powdered drink mixes.

_x__ INCREASE URINE MAGNESIUM

If your urine magnesium is low, you are advised to take a magnesium supplement, which is available over-the-counter.
you may require a formulation providing in the range of 300 to 500 milligrams per day, depending on your current intake of foods providing magnesium.

I hope these tips help you understand kidney stones and some of the ways to avoid them. Regards, Kathy J. Shattler, MS,RDN

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