I Had a Kidney Stone. Now what?
Someone who has had kidney stones is more likely to get stones in the future. There are a number of factors at play that can cause a recurrence of kidney stones. An individuals metabolism, dietary and fluid intake, other medical conditions, as well as the anatomy of a persons urinary tract all contribute to the potential for kidney stone formation.
The good news is there are dietary and fluid management strategies to help you prevent stones. On this webpage we outline the general recommendations for all stone-formers as well as detail the specific treatments for conditions identified on 24-hour urine tests.
Six Dietary Recommendations for Everyone
1. Stay well hydrated
Kidney stones form in a concentrated urine. The more dilute you can make your urine the lower your chance is of having kidney stones. The goal is to increase your total urinary output to 2L(about a half gallon) or more even day. For many of us that will require increasing our fluid intake substantially. Water is best, but most all other liquids count as well. The best way to determine your total urine output is to measure it, such as is done in a 24 hour urine.
2. Monitor and limit your sodium intake
High salt diets affects the way your kidneys process other minerals in the urine. It also leads to a concentrated urine. Many of us have sodium intake that is simply too high. Aim to decrease dietary sodium intake to less than 2300mg/day. Avoiding pre-processed foods such as canned foods is the usual first step, but many foods contain high sodium that usually are considered "healthy", such as cheese, bread, and many "healthy" snacks.
3. Moderate and limit your animal protein intake
Animal protein increases kidney stone risk. Aim to decrease dietary intake of non-dairy animal protein, that includes beef, pork, chicken and fish. Limit portion size. Aim for a goal of protein daily of 0.8-1.2 mg/kg of your "ideal" body weight from all food sources. Vegetable and dairy protein can be a major contributor to your overall protein intake
4. Monitor and limit high oxalate foods
Many plant based food have a mineral called oxalate that combines easily with calcium to create kidney stones. Although we encourage you to focus on a plant-based diet, there are some plant foods that are best to limit. Limit high oxalate foods in your diet. There are lists you should refer to (see downloads below) but common culprits of high oxalate foods are spinach, beets, rhubarb, almonds and peanuts. Also very high doses (multiples above RDA) of Vitamin C also increase oxalate in the urine, and should be avoided.
5. Add Citrate to your diet
Citrate is a mineral found in the urine that can decrease your risk of stones. Citrate concentration in the urine is affected by hydration, protein and salt intake as well as by your body's own physiology. Higher citrate concentrations in the urine can decrease stone risk. You can increase urinary citrate through a diet high in fresh fruits and vegetables, oranges, lemons and limes are naturally high in citrate. Crystal Light Lemonade can also increase urinary citrate levels to a small degree. Dietary changes only increase citrate to a moderate degree. If you are diagnosed with chronically or severely low citrate levels in the urine on 24 hour urine testing, supplements are often prescribed.
6. Make sure you are getting enough Calcium, Magnesium and Potassium in your diet
Your body needs Calcium, Potassium and Magnesium Many people limit their intake of calcium thinking that because most kidney stones are made from calcium they should decrease calcium in the diet. That is wrong; patients with very low calcium intake may actually have higher kidney stone risk. Moderate Calcium consumption of 1000- 1200mg/day is good for body function and bone health. Do it. Foods high in calcium such as dairy, cheese, yogurt, milk and foods high in minerals such as fruit juices with added calcium and vegetables high in minerals such as beans, lentils, kale, broccoli, tofu, whole grain cereals all contain the calcium, magnesium and potassium your body needs. Most people do not need extra calcium in their diet in the form of supplements if eating a healthy diet.
24-hour Urine Testing for Kidney Stone Prevention
It matters what minerals concentratie in your urine over time. A 24 hour time period is long enough to get a representation of your urine concentration. Two 24 hour collections are more accurate than one. Testing your urine can tell you what needs adjustment to prevent kidney stones.
What is a 24 hour urine? Why do I need to do this?
Targeted Prevention for kidney stones
It matters what the average concentration of minerals is in your urine. Because kidney tones form over a long petriod of time, it matters what the concentration of the urine is over a longer period of time. A 24 hour time period is long enough to get a representation of your urine concentration. Two 24 hour collections is better than one.
Specific electrolytes and minerals are checked and recommendations for stone prevention are made depending on the results,
What gets tested in a 24 hour urine?
Volume
One of the major culprits of kidney stone formation is low overall urine output. Aim for a 2 liter (half gallon) daily output of urine. You may need to drink much more than 2 liters daily to make that much urine depending on your body's physiology.
For many, many patients a low urine volume may be the only abnormal finding on a 24 hour urine test.
Creatinine
Your body produces something called creatinine as part of normal function and it tends to produce creatinine at a pretty steady rate depending on your body size. The reason creatinine is tested is to make sure the collection is accurate, e.g. if the level of creatinine is lower or higher than expected you may not have collected an accurate 24 hour colection
pH
A low urine pH reflects the body's acid/base balance. A chronically low urine pH can put a patient at risk of Uric Acid stones. Patients with uric acid stones and a low pH have the unique opportunity to actually dissolve existing stones and prevent future stones by raising the urine pH through specific supplements to raise the urine pH
Sodium
Sodium output reflects intake of sodium. High urine sodium means that you are taking in too much salt. When the kidney has to get risk of too much sodium it affects other mineral composition in the urine leading to stones. Restriction of sodium in the diet is the only way to correct this.
Calcium
High calcium levels in the urine are most often from the kidney "leaking" calcium into the urine inadvertently. It is usually not related to how much calcium is in your diet. When there are high concentrations of calcium in the urine it can lead to stones. Most often levels of calcium too high in the urine are corrected with medication such as chlorthalidone, hydrochlorothiazide or indapamide.
Oxalate
Oxlalatae is a mineral found in plant foods. Some foods are very high in oxalate, Limiting the amount of oxalate in your diet decrease your kidney stone risk. Paying attention of foods high in oxalate can help limit the amount of oxalate in the urine.
Magnesium
Magnesium is a stone inhibitor. Low magnesium levels in the urine increase your stone risk. Magnesium supplementation can easily be obtained as over the counter supplement if needed according to 24 hour urines.
Uric Acid
Uric acid excretion is often related to animal protein intake in the diet. High uric acid levels in the uirine are usually corrected with dietary changes but also may be treated with medication if you have a history of high uric acid levels in the blood and a history of gout.
Common 24-hour Urine Abnormalities
Below is a list of the common 24 hour urine abnormalities that we see and ways we commonly treat these problems. The downloadable PDF contains all the information for 24 hour urine testing.
Low Urine Volume
Increasing urine volume is a relatively simple solution for many kidney stone formers. Drink more fluid. water is best, but many other fluids also increase urinary output.
Strategies for increasing urinary output and drinking more fluid include:
Timed fluid intake. Aim for a set amount of fluid intake per time unite. One glass an hour, for instance.
Set a goal for fluid intake. fill a bottle at the beginning of the day and aim to drink the entire bottle by end of day.
Set fluid intake by urine concentration. If the urine is concentrated then drink until the urine clears.
Carry a water bottle everywhere. Having water available increases your chance of drinking more. The kids are all about it. Try it.
Urine pH Adjustment
Raising the urine pH can dissolve and prevent uric acid stones. Hydration, eating a balanced, plant-based diet, and limiting acidic foods such as carbonated beverages are all helpful to keep a health urine pH level.
Supplementation may be need for some people to improve pH levels, usually in the form of potassium citrate or common baking soda.
Too Much Calcium or Hypercalciuria
Calcium combines with oxalate and phosphate in the urine to make kidney stones. higher concentration of Calcium, oxalate and phosphate within the urine increase kidney stone risk. All of us have some calcium in the urine, usually less than 200 mg/day. Some kidney stone formers have much more, with kidney stone risk increasing significantly above 275-300 mg/day of calcium in the urine.
Most elevated calcium is due to a kidney filtering issue called a "renal leak." Patients with this type of hypercalciuria are treated with a medication called a diuretic, most often chlorthalidone, hydrochlorothiazide or indapamide. People taking diuretics need to be monitored for lower potassium levels in the blood, a side effect of the medication.
Other causes of high urine calcium include hyperparathyroidism and, very infrequently, too much calcium absorption from the intestines.
Hypocitraturia
Cirate is a component of urine and is reflective of acid-base balance within the body. Citrate is a stone inhibiting mineral. Lower levels of citrate can increase stone risk' higher levels of citrate decrease stone risk.
Patients diagnosed with low levels of citrate in the urine can increase citrate through supplementation.
Citrate is found naturally within fruits and vegetables, and is in high concentrations in oranges and lemons. But simply adding a little orange juice or lemonade to the diet does not give the level of supplementation many people need. Most often a medication called Potassium Citrate is used.
Hyperoxaluria
Oxalate is a mineral in many plant based foods. Some foods have more oxalate than others.
Lowering oxalate in the urine is simply a matter of calculating intake of oxalate. A simple guideline for oxalate consumption is 100 mg oxalate daily.
Oxalate is excreted in the urine or in the stool. One reason you need adequate calcium in the diet is because the calcium will bind to oxalate in the gut. Once bound by calcium, the oxalate cannot be absorbed into the bloodstream and then the oxalate is excreted in the stool.
Hyperuricosuria
Uric acid is a byproduct or protein breakdown that is normally excreted through the kidneys. Too much uric acid in the urine can lead to uric acid kidney stones. Too much uric acid in the bloodstream can lead to gout.
Hyperuricosuria may be a result of genetic factors or can be associated with conditions such as certain metabolic disorders or kidney dysfunction.
Treatment for hyperuricosuria may involve lifestyle modifications, dietary changes, and medications to help reduce uric acid levels in the urine.
Uric acid stones are typically treated with adjustment of urine pH.
Low Magnesium or Hypomagnesuria
Low levels of magnesium in the urine are almost always dietary deficiency of magnesium. The recommended daily intake for a health adult is 350-400 mg/day. Dietary sources of magnesium include nuts, seeds, whole grains, leafy green vegetables, and legumes.
Magnesium supplements can be taken and purchased over the counter. 400 mg/day is an appropriate level of supplementation for most if your urine or blood levels are lower than ideal.
Too Much Sodium
Salt is essential for life. Salt adds flavor and acts as a preservative. Wars and confilicts have been waged to control salt deposits and trade routes. Gandhi marched to the sea in an act of civil disobedience against British salt taxes. Salt...is good.
Except all of us consume too much of it. In our age or ready abundance salt is everywhere in our foods. The salt load in our diets can lead to kidney stones in those who have salt sensitive kidneys, high blood pressure, or heart disease.
Limiting sodium intake is best for all of use. Kidney stone formers should try to limit sodium intake to less than 2500 mg/day.