Find the source and stop the pain of kidney stones. Hard masses that grow from crystals forming in the kidneys, they typically cause severe back pain that may radiate to the groin area. According to research or other evidence, the following self-care steps may be helpful.
- Drink plenty of fluids
Water, lemonade, and most fruit juices can help dilute the substances in the urine that form kidney stones; avoid grapefruit juice and soft drinks
- Don't eat too much animal protein
Diets high in animal protein are linked to increased calcium in the urine, which contributes to oxalate stones
- Avoid foods with organic acids (oxalates) that help stones form
Limit spinach, rhubarb, beetroot greens, nuts, chocolate, tea, bran, almonds, peanuts, and strawberries, which appear to increase urinary oxalate levels
- Protect yourself with vitamin B6 and magnesium
50 mg a day of vitamin B6 with 200 to 400 mg a day of magnesium (preferably the citrate form) may inhibit oxalate stone formation
About This Condition
Kidney stones are hard masses that can grow from crystals forming within the kidneys. Doctors call kidney stones "renal calculi," and the condition of having such stones "nephrolithiasis."
Most kidney stones are made of calcium oxalate. People with a history of kidney stone formation should talk with their doctor to learn what type of stones they have—approximately one stone in three is made of something other than calcium oxalate and one in five contains little if any calcium in any form. Calcium oxalate stone formation is rare in primitive societies, suggesting that this condition is preventable.1 People who have formed a calcium oxalate stone are at high risk of forming another kidney stone.
The information included in this article pertains to prevention of calcium oxalate kidney stone recurrence only—not to other kidney stones or to the treatment of acute disease. The term "kidney stone" will refer only to calcium oxalate stones. However, information regarding how natural substances affect urinary levels of calcium may also be important for people with a history of calcium phosphate stones.
Kidney stones often cause severe back or flank pain, which may radiate down to the groin region. Sometimes kidney stones are accompanied by gastrointestinal symptoms, chills, fever, and blood in urine.
The right diet is the key to managing many diseases and to improving general quality of life. For this condition, scientific research has found benefit in the following healthy eating tips.
Recommendation Why Ask your doctor about bran Bran, a rich source of insoluble fiber, reduces calcium absorption, which in turn reduces calcium in the urine. Ask your doctor if supplementing with bran is right for you.
Bran, a rich source of insoluble fiber, reduces the absorption of calcium, which in turn causes urinary calcium to fall. In one trial, risk of forming kidney stones was significantly reduced simply by adding one-half ounce of rice bran per day to the diet. Oat and wheat bran are also good sources of insoluble fiber and are available in natural food stores and supermarkets. Before supplementing with bran, however, people should check with a doctor, because some people—even a few with kidney stones—don't absorb enough calcium. For those people, supplementing with bran might deprive them of much-needed calcium.
Drink lemonade Lemons are high in citric acid, which may protect against kidney stones. One study found that drinking 2 liters of lemonade per day helped prevent kidney stones.
Citric acid (citrate) is found in many foods and may also protect against kidney stone formation. The best food source commonly available is citrus fruits, particularly lemons. One study found that drinking 2 liters (approximately 2 quarts) of lemonade per day improved the quality of the urine in ways that are associated with kidney stone prevention. Lemonade was far more effective in modifying these urinary parameters than orange juice. In another study, drinking 2 liters of lemonade per day for an average of about four years decreased the recurrence rate of kidney stones by 87%. However, that improvement was not statistically significant, because of the small number of patients treated. The lemonade was made by mixing 4 oz lemon juice with enough water to make 2 liters. The smallest amount of sweetener possible should be added to make the taste acceptable.
Drink plenty of fluids Water and most fruit juices can help dilute the substances in the urine that form kidney stones
Drinking water increases the volume of urine. In the process, substances that form kidney stones are diluted, reducing the risk of kidney stone recurrence. For this reason, people with a history of kidney stones should drink at least two quarts per day. It is particularly important that people in hot climates increase their fluid intake to reduce their risk.
Eat more fruits and veggies Potassium reduces the amount of calcium lost in the urine, and therefore may reduce the risk of kidney stones. The best way to get more potassium is to eat fruits and vegetables.
Potassium reduces urinary calcium excretion, and people who eat high amounts of dietary potassium appear to be at low risk of forming kidney stones. Most kidney stone research involving potassium supplementation uses the form potassium citrate. When a group of stone formers was given 5 grams of potassium citrate three times daily in addition to their regular drug treatment for 28 months, they had a significantly lower rate of stone recurrence compared to those taking potassium for only eight months and to those taking no potassium at all. Although citrate itself may lower the risk of stone recurrence (see below), in some potassium research, a significant decrease in urinary calcium occurs even in the absence of added citrate. This finding suggests that increasing potassium itself may reduce the risk of kidney stone recurrence. The best way to increase potassium is to eat fruits and vegetables. The level of potassium in food is much higher than the small amounts found in supplements.
Steer clear of sugar People who form kidney stones have been reported to process sugar abnormally. As a result, some doctors recommend that people who form stones avoid sugar.
People who form kidney stones have been reported to process sugar abnormally. Sugar has also been reported to increase urinary oxalate, and in some reports, urinary calcium as well. As a result, some doctors recommend that people who form stones avoid sugar. To what extent, if any, such a dietary change decreased the risk of stone recurrence has not been studied and remains unclear.
Try a vegetarian diet Vegetarians have been reported to be at lower risk for kidney stones.
Increased levels of urinary calcium increase the risk of stone formation. Consumption of animal protein from meat, dairy, poultry, or fish increases urinary calcium. Perhaps for this reason, consumption of animal protein has been linked to an increased risk of forming stones and vegetarians have been reported to be at lower risk for stone formation in some reports. As a result, many researchers and some doctors believe that people with a history of kidney stone formation should restrict intake of animal foods high in protein.
In one controlled trial, contrary to expectations, after 4.5 years of follow-up, those who restricted their dietary protein actually had an increased risk of forming a kidney stone, compared with the control group. The findings of this trial conflict with the outcomes of most preliminary studies, and need to be confirmed by further clinical trials. Other researchers have found that a low-protein diet reduces the risk of forming stones. Although high-protein diets should probably be avoided by people with kidney stones, the effect of restricting dietary protein to low levels (below the RDA level of 0.8 grams per 2.2 pounds of body weight per day) remains unclear. Until more is known, it makes sense to consume a diet with a moderate amount of protein, perhaps partially limiting animal protein, but not limiting protein from vegetarian sources, such as nuts and beans.
Use coffee or tea cautiously Coffee and tea increase urinary oxalate excretion, possibly increasing risk of stones. However, observational studies have associated drinking more of either with lower risk. None of this research is strong, so coffee and tea's role in stone formation is unclear.
Drinking coffee or other caffeine-containing beverages increases urinary calcium. Long-term caffeine consumers are reported to have an increased risk of osteoporosis, suggesting that the increase in urinary calcium caused by caffeine consumption may be significant. However, coffee consists mostly of water, and increasing water consumption is known to reduce the risk of forming a kidney stone. While many doctors are concerned about the possible negative effects of caffeine consumption in people with a history of kidney stones, preliminary studies in both men and women have found that coffee and tea consumption is actually associated with a reduced risk of forming a kidney stone. These reports suggest that the helpful effect of consuming more water by drinking coffee or tea may compensate for the theoretically harmful effect that caffeine has in elevating urinary calcium. Therefore, the bulk of current research suggests that it is not important for kidney stone formers to avoid coffee and tea.
Eat the right diet with certain supplements In one study, recurrence rate of kidney stones dropped when people restricted salt, sugar, animal protein, and foods rich in oxalate, and after people supplemented with potassium citrate and magnesium citrate.
Some citrate research conducted with people who have a history of kidney stones involves supplementation with a combination of potassium citrate and magnesium citrate. In one double-blind trial, the recurrence rate of kidney stones dropped from 64% to 13% for those receiving high amounts of both supplements. In that trial, people were instructed to take six pills per day—enough potassium citrate to provide 1,600 mg of potassium and enough magnesium citrate to provide 500 mg of magnesium. Both placebo and citrate groups were also advised to restrict salt, sugar, animal protein, and foods rich in oxalate. Other trials have also shown that potassium and magnesium citrate supplementation reduces kidney stone recurrences.
Sidestep salt Some doctors recommend that people with a history of kidney stones reduce salt intake, but to what extent that would reduce stone recurrence remains unclear.
Salt increases urinary calcium excretion in stone formers. In theory, this should increase the risk of forming a stone. As a result, some researchers have suggested that reducing dietary salt may be a useful way to decrease the chance of forming additional stones. Increasing dietary salt has also affected a variety of other risk factors in ways that suggest an increased chance of kidney stone formation. Some doctors recommend that people with a history of kidney stones reduce salt intake. To what extent such a dietary change would reduce the risk of stone recurrence remains unclear.
Avoid foods with oxalates that can help stones form Limit your intake of spinach, rhubarb, beet greens, nuts, chocolate, almonds, peanuts, and strawberries, which appear to significantly increase urinary oxalate levels.
Increasing dietary oxalate can lead to an increase in urinary oxalate excretion. Increased urinary oxalate increases the risk of stone formation. As a result, most doctors agree that kidney stone formers should reduce their intake of oxalate from food as a way to reduce urinary oxalate. Many foods contain oxalate; however, only a few—spinach, rhubarb, beet greens, nuts, chocolate, tea, bran, almonds, peanuts, and strawberries—appear to significantly increase urinary oxalate levels.
Avoid grapefruit juice Drinking grapefruit juice has been linked to an increased risk of kidney stones in two large studies.
Drinking grapefruit juice has been linked to an increased risk of kidney stones in two large studies. Whether grapefruit juice actually causes kidney stone recurrence or is merely associated with something else that increases risks remains unclear; some doctors suggest that people with a history of stones should restrict grapefruit juice intake until more is known.
Halt the soda habit The phosphoric acid found in soft drinks is thought to affect calcium metabolism in ways that might increase kidney stone recurrence risk.
The findings of some but not all studies suggest that consumption of soft drinks may increase the risk of forming a kidney stone. The phosphoric acid found in these beverages is thought to affect calcium metabolism in ways that might increase kidney stone recurrence risk.
What Are "Star" Ratings?
Our proprietary "Star-Rating" system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by some in the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
Supplement Why 3 StarsMagnesium Citrate and Potassium Citrate (Abdominal Pain)1,600 mg daily potassium as citrate and 500 mg daily of magnesium as citrate Supplementing with a combination of potassium citrate and magnesium citrate may reduce the recurrence rate of kidney stones.Some citrate research conducted with people who have a history of kidney stones involves supplementation with a combination of potassium citrate and magnesium citrate. In one double-blind trial, the recurrence rate of kidney stones dropped from 64% to 13% for those receiving high amounts of both supplements. In that trial, people were instructed to take six pills per day—enough potassium citrate to provide 1,600 mg of potassium and enough magnesium citrate to provide 500 mg of magnesium. Both placebo and citrate groups were also advised to restrict salt, sugar, animal protein, and foods rich in oxalate. Other trials have also shown that potassium and magnesium citrate supplementation reduces kidney stone recurrences. 2 StarsIP-6120 mg daily IP-6 (inositol hexaphosphate, also called phytic acid) reduces urinary calcium levels and may reduce the risk of forming a kidney stone.
IP-6 (inositol hexaphosphate, also called phytic acid) reduces urinary calcium levels and may reduce the risk of forming a kidney stone. In one trial, 120 mg per day of IP-6 for 15 days significantly reduced the formation of calcium oxalate crystals in the urine of people with a history of kidney stone formation.
1 StarChondroitin SulfateRefer to label instructions Chondroitin sulfate may help reduce the risk of kidney stone formation. One trial found that glycosamionoglycans significantly lowered urinary oxalate levels, which reduces the risk of stone formation.
Chondroitin sulfate may play a role in reducing the risk of kidney stone formation. One trial found 60 mg per day of glycosamionoglycans significantly lowered urinary oxalate levels in stone formers. Chondroitin sulfate is a type of glycosaminoglycan. A decrease in urinary oxalate levels should reduce the risk of stone formation.
1 StarPumpkin SeedsRefer to label instructions Two trials from Thailand reported that eating pumpkin seeds reduces urinary risk factors for forming kidney stones.
Two trials from Thailand reported that eating pumpkin seeds reduces urinary risk factors for forming kidney stones. One of those trials, which studied the effects of pumpkin seeds on indicators of the risk of stone formation in children, used 60 mg per 2.2 pounds of body weight—the equivalent of only a fraction of an ounce per day for an adult. The active constituents of pumpkin seeds responsible for this action have not been identified.
1 StarVitamin B6Refer to label instructions Taking vitamin B6 with magnesium can inhibit oxalate stone formation.
Both magnesium and vitamin B6 are used by the body to convert oxalate into other substances. Vitamin B6 deficiency leads to an increase in kidney stones as a result of elevated urinary oxalate. Vitamin B6 is also known to reduce elevated urinary oxalate in some stone formers who are not necessarily B6 deficient.
Years ago, the Merck Manual recommended 100–200 mg of vitamin B6 and 200 mg of magnesium per day for some kidney stone formers with elevated urinary oxalate. Most trials have shown that supplementing with magnesium and/or vitamin B6 significantly lowers the risk of forming kidney stones. Results have varied from only a slight reduction in recurrences to a greater than 90% decrease in recurrences.
Optimal supplemental levels of vitamin B6 and magnesium for people with kidney stones remain unknown. Some doctors advise 200–400 mg per day of magnesium. While the effective intake of vitamin B6 appears to be as low as 10–50 mg per day, certain people with elevated urinary oxalate may require much higher amounts, and therefore require medical supervision. In some cases, as much as 1,000 mg of vitamin B6 per day (a potentially toxic level) has been used successfully.
Doctors who do advocate use of magnesium for people with a history of stone formation generally suggest the use of magnesium citrate because citrate itself reduces kidney stone recurrences. As with calcium supplementation, it appears important to take magnesium with meals in order for it to reduce kidney stone risks by lowering urinary oxalate.
1 StarVitamin ERefer to label instructions In one study, supplementing with synthetic vitamin E was found to reduce several risk factors for kidney stone formation in people with elevated levels of urinary oxalate.
In a double-blind trial, supplementation with 200 IU of synthetic vitamin E per day was found to reduce several risk factors for kidney stone formation in people with elevated levels of urinary oxalate.
- Find Drug Interaction Information
1. Blacklock N. Renal stone. In: Western Diseases: Their Emergence and Prevention, ed. DP Burkitt and HC Trowell. Cambridge, MA: Harvard Press, 1981, 60–70.
Last Review: 06-08-2015
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2021.