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If we put together everything on this site about diet for kidney stone prevention we get a reasonable and consistent image of one basic pattern. It is more or less what is ideal for idiopathic hypercalciuria and for reducing urine oxalate. It is the diet that has been used in the one major trial of diet for stone prevention. It accords with modern recommendations for the health of the American people. More or less, after all is said, there is only one diet plan that meets the needs for kidney stone prevention and we have called it ‘The Kidney Stone Diet.’

Of course, we are speaking of the diet for treatment of idiopathic calcium stones. Stones from systemic diseases, like bowel disease, primary hyperparathyroidism, primary hyperoxaluria, are treated by treating those diseases, and that is a different matter altogether. But those are the exceptions. Of the millions of American people with stones, almost all are idiopathic.

There will be surprises. Diet oxalate always matters but less so than you might think once the full diet is in place. Calcium will seem odd to you unless you have been a frequenter of this site. Sodium will seem all too familiar.

Dissecting the Diet


High calcium intake is essential for stone formers. They have bones and many have idiopathic hypercalciuria that can cause bone disease unless there is a lot of diet calcium intake. Oxalate absorption is greatly hampered by high calcium intake, if the calcium is eaten when the oxalate is eaten.

It is not only stone formers who need a lot of calcium. The new FDA diet recommendations include high calcium intake for all Americans.

How high is high?

More or less, throughout life, men or women, girls or boys, the range hovers between 1,000 and 1,200 mg daily. This amount of calcium is ideal for both protection against bone mineral loss from idiopathic hypercalciuria and reducing oxalate absorption. The unique part for stone formers is timing the calcium to go with the main oxalate containing foods during the day.


Urine calcium follows urine sodium like a shadow. The lower the sodium the lower the calcium. In the one bone study that seriously looked at the matter, it was the combination of low sodium diet and high calcium diet that led to positive bone calcium balance – uptake of mineral into bone as opposed to bone loss.

So, what is ‘low sodium. The new FDA recommendations are an intake below 2300 mg (100 mEq for those of you who read lab reports). For those with high blood pressure – treated with drugs or not – 1,500 mg is ideal. For stone formers, the latter, 1,500 is ideal because it brings urine calcium of hypercalciuric people near the normal range, and also benefits those without hypercalciuria by making urine calcium as low as possible.

If 1,500 mg is the ideal for the kidney stone diet, 2,300 is the absolute upper limit, and people will more or less want to live somewhere in between, hopefully at the low end.

Refined Sugar

Refined sugar is sugar that has been extracted from plants into the white stuff you buy in bulk and add to cake and cookie and brownie recipes, and use to make candy. The sugar in plants and fruits is packaged along with fiber and released slowly so it is very safe. Once you extract it into white powder it is absorbed very fast. We are not made to use this well. Blood sugar and insulin rise a lot, fat is formed, and it is not healthy.

Jack Lemann first showed decades ago that simply eating 100 gm of glucose causes a rapid rise in urine calcium with – can you imagine worse? – a concomitant fall in urine volume so supersaturations rise extremely high. It is the perfect storm. Urine calcium of people with hypercalciuria rises a lot more than in those without it, so it is evil in family members of stone formers. Since about one half of the relatives of a hypercalciuric stone former will be hypercalciuric because of genetics, even the children are put at risk by high sugar intakes. The worst part is that hypercalciuria is silent until stones or crystals form, so no one can know.

Very reduced refined sugar intake is emphasized in the new government diet recommendations because of American obesity and diabetes. The recommendation is that less than 10% of all diet carbohydrates come in the form of added sugar which means very little sweets. This means sugars that are added to foods, not the natural sugars in fruits and some vegetables. The latter are absorbed more slowly and are safe. Obviously candy and cake and brownies and all the other good stuff is in the very bad category.


Our long and difficult review of the protein story make a main point. People absolutely need at least 0.8 gm/day per kilogram of body weight of protein and need no more than 1 gm/d/kg. WIthin that narrow range there is a measurable but modest effect of protein on urine calcium that can be neglected if sodium is controlled. So we see no physiological basis or trial evidence that ‘low protein diet’ is appropriate. By low we could only mean 0.8gm/kg/d. The one comprehensive kidney stone diet trial implies a low protein intake but in fact employed 93 gm of diet protein – which is a lot. The diet change was to make 40% of it be plant based. But there is no evidence that plant protein reduces stones or urine calcium compared to meat protein. Plant based protein sources are often rich in oxalate.


All things being equal we have advocated for a low oxalate intake between 50 and 100 mg daily. However Ross Holmes showed clearly that with very high calcium intakes such as 1,000 to 1,200 mg daily, absorption of diet oxalate is less and therefore the need for strict control is also less. In the one diet trial by Borghi diet oxalate was 200 mg/day but diet calcium was high and urine oxalate actually lower than in his contrast group with low calcium diet and less oxalate intake.

The ideal approach as best we can tell is to put in place the high calcium diet, aim for about 200 mg of oxalate, which is easier to accomplish than lower values, and measure the urine results. If despite high calcium intake urine oxalate is creating risk of stones then diet needs to be altered appropriately.

Some people seem to absorb oxalate more efficiently than others, so there are no fixed rules. Many have normal urine oxalate excretions without any diet change at all. Many who have undesirably high urine oxalate at their first labs will show a marked fall with the higher calcium intake and need no further restrictions.

Some will remain hyperoxaluric despite the calcium and it is for them that very restricted oxalate diets can be reserved.

One key is urine collections to see that calcium alone can accomplish for any one person.

The other key is timing. The diet calcium must come in the same meals that contain the bulk of the day’s oxalate. Without that precaution calcium might not work well in this regard.


We have covered this topic completely. The urine volume you want is above 2.5 l/d, the amount of fluids needed is about 3 l/d and you just have to experiment to find the exact intake for you, and also allow for weather, occupation, sports. Obviously sugared fluids have always been unfavored on this site, and you need to avoid them. The other major issue is steadiness over the day and into the evening. Overnight we just take our chances in most cases.

There You Have It

The kidney stone diet is one thing: High calcium, low sodium, low refined sugar, normal protein, flexible oxalate management that depends on how high urine oxalate is once high diet calcium is achieved, and of course high fluids.

This site is rich in articles that pertain to the kidney stone diet – it was built in part for this purpose. The home page lists articles by topic and you can find there the ones you need. Here is a brief summary with links.

High calcium and low sodium: 1,000 to 1,200 mg calcium 65 – 100 mEq (1,500 to 2,300 mg) sodium and care about oxalate (50 to 200 mg/day) can be achieved using our list of foods that meet all three requirements. It is essential that calcium be taken in with the meals that contain appreciable oxalate.

Low refined sugar (below 10% of daily carbohydrate intake): This is best thought of as a major reduction in sweets – cookies, candy, sugared drinks, cake, pie. Fruits are not a problem, but smoothies that break up the fruit may liberate their sugars and overcome the ‘slow release’ properties of the intact fruits themselves. We did not write an article about this matter because it is simply to give up what many of us love.

Normal protein intake – this translates into 1/2 to 2/3 pound of meats daily for an average adult. For stones, the issue of red meat vs. fish or chicken does not matter. Vegetable protein sources such as soy are high enough in oxalate one cannot recommend them.

High fluids and how to get them are in many articles on this site.

When Do You Begin the Diet

To us there is no question it should be after even one stone. The diet accords with all modern recommendations. The only special features are attention to oxalate and to timing of calcium with oxalate containing foods. High Fluids are more of a task, but after one stone the one trial showed a marked reduction in second stone formation with urine volumes above 2.5 l/day compared to the 1 l/d of the control group.

A more subtle matter is family members. Idiopathic hypercalciuria causes both stones and bone disease, and is hereditary. About half of first degree relatives of hypercalciuric people with stones have the trait even without stones. Given this, and also that the kidney stone diet is benign and in line with what we all should be eating, why not make it the general family diet as well?

I (Jill), have recently put together a private FB page called THE Kidney Stone Diet.  It is a group that helps educate you on your physician prescribed treatment plans. I moderate it to keep it clinically sound.  Come on over and join the discussion!

66 Responses to “THE KIDNEY STONE DIET”

  1. Kumar

    Dear Doctor,

    I was diagnosed with 8mm calculus on my upper right ureter with severe unbearable pain on April 2016. I tried not to take any surgery / lithotripsy and wanted to cure it by some traditional Indian medicines. But this doesn’t helped. I was taking pain killers during this period and was filtering the urine that I passed using a sieve to see if the stone has passed out in the urine. As I couldn’t see any stone fragments in the urine, I thought to go ahead with the lithotripsy as suggested by the Urologist. After the surgery, I was not discharged immediately from the hospital as I developed some infections in my urinary tract, which took nearly one month of regular antibiotic medicines injected into my veins. When I felt normal after a month, I resumed to my work as a normal person, but again I got infection on the next day. It took another one month for me to cure from it.

    After a year in March 2017, I took an ultrasound scan as a follow-up check and it was diagnosed that my right kidney has two or three stones of sizes 3 or 4 mm. Urologist said that these are small stones and it will pass away while urinating. I felt comfortable and returned to work. Now in July 2017, I felt some discomfort on my right side kidney and took an Ultrasound scan. The recent report says that I have a 5mm echogenic foci (right renal calculus) at the lower pole calyx region.

    I have been drinking lot of water every day. Atleast 3 to 5 litres as suggested by the doctor. I am not sure if this is really a lot of water. I have been eating apples, oranges, fish / chicken once or twice in a week. I am close to an obese person with my BMI exceeding 27. I am aged 35-Male. For the past 3 months, I have been on vegetarian diet and I was shocked to see that I have a 5mm stone in my kidney. I feel disturbed as I do not know what causes these stones to occur and how to prevent it. I have been regularly taking atleast 3 litres water every day. But the duration of taking the water is different. I drink 3-4 litres of water in the day time when I don’t eat much food due to my work and I take 0.5-1 litres of water after my stomach-filled dinner.

    Can you please advise me about my current scan report saying 5mm right renal calculi at the lower calyx region? What should I do now? Should I go for any surgery or any other procedures? Or is there any possibility for this stone to get out through urine in any way? I found this website as really useful and I thought to ask for your suggestion.

    (Please note that the scan report also says that mild right hydronephrosis and hydroureter was noted. I always feels some discomfort or pressing feeling on my right side hip. I do not know what to do for this, as my previous Urologists also observed this dialation of my right kidney, but have not suggested anything to do to reduce or avoid this. All they said was to drink lot of water and to avoid some foods).

    Kindly advise. Awaiting for your reply. Thanks.

    • Fredric Coe, MD

      Hi Kumar, It sounds like you are making new stones, which means you have some problems that need to be evaluated and treated. Before considering surgery, you need to know why stones form because after surgery more may well form. Here is a good plan for prevention. I cannot advise on the timing of surgery because that requires I view your scans and take medical responsibility, which is obviously not practical. Regards, Fred Coe

  2. Joe Donohue

    I have just had my first bout with Kidney stones. A normal day turned into a disaster in a 30 minute time frame. The pain was unbearable and I found myself screaming in agony. I had 3 stones in the right side. Two were 4mm and one 5mm. Two of the stones were actually caught up in the tube and the following day were taken out with surgery. I am a little sore on my recovery. A stent was placed in and is to be removed tomorrow. this website and it’s information is wonderful as I begin to change a terrible diet with high salt and soda intake, fast food and lack of proper diet in general, which is now a huge issue to me. I want no return of stones and will follow instructions to see that i do everything needed to work on diet and prevention! Thank you !!

  3. Lea Ann

    I cried when I found this website, and am so grateful that you have put together such an exhaustive amt of patient and scientific information, as I have felt terribly alone even though I live in a very urban and progressive area. I am switching my care over to Dr Stohler at UCSF whom you likely have heard of, as the community medicine approach is not working. I’ve just finished my third lithotripsy, after a 7mm stone episode, and five years ago had four in my other kidney. My father was on dialysis 4x per week and I do not want his fate. I’m a calcium oxylate stone carrier, and will know more after I see the big guns at UCSF but working on diet changes, and in San Francisco, we eat well, and eat some odd things so I have some questions after looking on the short list and long list. I’m bunching these ?s all together so you could answer easily.
    I hate salt, and have been a pescatarian for 40 years, I’m 57 yold
    1) I end up loosing alot of electrolytes on this much water….do you have any electrolyte replacement you recommend?
    2) White rice gets me totally constipated, can I use BASMATI rice which is white and from India
    3) Are chickpeas okay? We eat alot of those out here?
    4) Is Gluten Free good diet to follow in terms of like crackers etc because it is non wheat?
    5) Bread- what should I be looking for? Oat Bread or Flax Seed Bread?
    6) I run hypoglycemic but not enough to be on meds, I have used gorp as a resource for years. I don’t like the granola bars filled with sugars. Can you recommend a “safe” protein bar?
    7) Protein Shake – I use SOLGAR WHEY protein powder every day–Called Whey to Go. I put a 1/4 cup of strawberries and plain organic yogurt into it. I has Calcium, Phosphorus, Mag, low sodium, Potassium and many Essential Amino Acids and Non Essential Amino acids. Hoping to be able to continue that
    8) And I”m reading that both coffee and green tea are okay?
    9) Dr Stohler has found in his lab that warm lemon juice water every morning inhibits stone formation, and also is looking at high zinc as a contributing factor – all of which you may already know, just an fyi.

    Sorry for all these questions, hopefully the answers will help others! You all deserve deep bows of gratitude for helping so many of us every day. These events have literally caused ptsd for me, I have never known such pain, even in breaking my back (literally!) has anything hurt so much. I appreciate your time so much and this would help me greatly until I get into UCSF which could be a couple months down the road. Blessings upon you all!

    • Fredric Coe, MD

      Hi Lea Ann, Certainly the UCSF program is excellent and I do know Dr Stohler. Of course I do not know what is wrong with you. If your father went on dialysis because of calcium oxalate kidney stones, perhaps you have some serious disorder of oxalate metabolism. Possibly his dialysis was from other causes. As for sodium, the present US diet recommendations are for less than 2300 mg sodium daily – as a tolerable upper limit, and an ideal of 1500 mg – which is also ideal for most stone formers. But not if you have a serious oxalate disorder. Gluten free diets are for people with gluten sensitivities and are not healthy per se. GLuten experts warn against them for almost all people. I do not like any concentrates, bars, shakes, smoothies – food is better not taken apart. As for lemon juice, fruits and vegetables all contain considerable potassium as metabolizable anions, like citrate. The US diet recommendations of 5 servings of fruits and veggies daily will provide about 4,500 mg of potassium – over 100 mEq – which is far preferable to juices and the like. The article you have commented on has all the links. Here is a good article on how to get the most out of Dr Stohler. This one makes clear what evaluation you need. Regards, Fred Coe

  4. Amritha

    Hiiiii sir,
    My dad has being diagnoised with kidney stones a week before. Its diagnosed through scanning. The stone size is 5mm.
    Could you help me with suggesting some diet.

  5. Alicia petrakis

    My husband has had calcium oxilate stones for over 25 years (he’s only 52). He’s had numerous lithotripsy procedures as well as stents and catheters after removal. He has some scar tissue and related issues. He recently met with his urologist as well as a nephrologist. She is saying tomgo on a plant based diet low in
    Oxilates, increase water intake and decrease/eliminate salt. I Am confused. I have read information stating similar protocol however your site seems to say there is little correlation between animal protein and stone levels. We would like to understand the best approach as his body cannot handle any suregeries. We are open to trying anything. We’ve been doing plant based + fish for a week now. Also taking ACV and honey each morning and a ginger/Tumeric/honey and cocunut Milk drink at night. Thank in advance for anything you can do to help guide us in the right direction. Kindly. Alicia

    • jharris


      Thanks for writing. There is correlation between high protein intake and kidney stones and do not know where on the site you are seeing the contrary. If your husband has done a 24 hour urine collection I would be happy to take a look The Kidney Stone Prevention Course I offer would benefit your husband greatly. Please go to: to find out more. The apple cider vinegar is very popular right now, but we find not a lick of scientific evidence that it works for stone prevention and certainly will not dissolve any stone. The tumeric could actually be increasing his oxalate level as it is high in it.



  6. Brenda carleton

    There is valuable information here, I suspect, but you seriously need an editor.

    • Fredric Coe, MD

      Hi Brenda, Everyone needs an editor, certainly I do. But, alas, I am a professor who has no money to hire one. Perhaps you are an editor and would like to donate your skills to this project as I donate mine; that would be a virtue. Regards, Fred

    • Michael

      Well written article, thank you. Brenda has issues….

    • Clarissa Porche

      Brenda Carelton, it is hard to believe that after navigating through the WEALTH of valuable information for stone sufferers, all you managed to come up with for a comment was that an “editor” is needed. I suspect you are in need of some validation for whatever reason, though it could simply be that you are an egotist, with a delusional sense of grammatical superiority. Either way, seek help.

  7. Krishna

    Hello Doctor,

    My father has been suffering from kidney stones. He already had 2 kidney stone surgeries. First one was mini PCNL where the doctor made small hole and took the stones out. The stones as per the report were around 25mm. The smaller stone int he urinary pipes were removed through pipes that were inserted through the penis.

    After again 1 year he again developed kidney stone is both right and left kidney. A MDCT Scan of abdomen and CT urogram was done. As per the report single 10 mm intracortical cyst is seen in upper polar cortex of right kidney. Two calculi lager measuring 9×6 mm with HU641 and slight irregular margin and smaller one with 6.4×4.2 mm having slight irregular margin with HU317. Two calculi seen in left kidney in left renal pelvis and lower polar calyx. The largest one in lower polar calyx having irregular margin measuring 7.7×6.4 mm with HU692 and another one in renal pelvis having define margin measuring 5×4 cm with HU686.

    The blood test reported urea of 18 mg/dl (reference 15-45) and creatinine of 1.00 mg/dl(reference 0.7-1.2).

    Operation was then done -RT URSL with Laser Lithitripsy with doudle DJ stenting . The doctor then prescribed following medicine
    1. Tab Cetil
    2. Tab Levocide
    3. Tab Nise
    4. Tab Dolopar
    5. Tab Raciper
    6. Tab Alprax
    7. cap Nubex Forte

    The doctor then said that the stone in the left kidney shall be removed by ESWL (through sound wave shock) and the same was done.

    During the follow up after the operation and on the request of the doctor, 24 hour urine test and blood test was carried out. The report showed following result

    Urine Test
    1. calcium urine—– Not calcualted—— Reference Inverval(50-300.00 mg/24 hrs)
    2. Magnesium———-60 mg/24 hrs——–Reference (24-255)
    3. Uric Acid———-765 mg/24hrs——– Reference (Average Diet 250-750, Low Purine Diet <480 and High Purine Diet <1000)
    4. Phosphorus——-0.705 g/24hrs——-Reference (0.4-1.3)
    5. Oxalate———18.66 mg/24hrs——–Reference(7-44)

    The blood test for calcium and uric acid showed following result
    Calcium——11.5 mg/dl——-reference(8.4-10.2)
    uric acid——8.5 mg/dl———reference (3.4-7.0)

    After 8-9 months after the operation, my father again developed stone in both kidneys. The doctor here say stone are caused due to various reason and single reason cannot be pinpointed and he again say we need to operate.

    I humbly request you to suggest me what should I do and what are the thing that my father should do to avoid these stone. Its really painful to see going through operation. Furthermore, I have heard that kidney stone are so painful but my father never experienced these kind of pain. We only know he has stone after USG.

    Please do help

    • Fredric Coe, MD

      Hi Krishna, There are some things missing; do you know what the stones were made of? The urine test inexplicably leaves out the calcium and volume, perhaps most important of all. The other measurements are normal. His blood calcium is very high if the measurement is to be believed and that suggests primary hyperparathyroidism. For the diagnosis he needs a repeat fasting blood for calcium with serum PTH in the same sample, and a 24 hour urine with calcium and creatinine measured in it. If the calcium is still high and the PTH value is not suppressed and the urine calcium is high the diagnosis is likely. Surgery to remove the enlarged parathyroid gland is curative. Regards, Fred Coe

      • krishna

        Dear Sir,
        The calcium level was reported no calculated in the report because it was below the lower detection level. The stone was not analyzed.

        • krishna

          Dear Sir,
          The volume of 24 hrs urine collected was 5000mL and as per the report urine calcium was Less than 5.0 mg/dL. The calcium , 24 hrs urine was reported not calculated. Comment is also present which says, urine calcium is reported less than 5.00 mg/dL. Since lower detection level for calcium is 5.00 mg/dL. hence 24 hours urine calcium is reported “not calculated”

          Please do help

        • Fredric Coe, MD

          Hi Krishna, This is in response to both of your comments. The large urine volume has diluted the calcium but if the volume is really 5 liters and the collection is complete – not under collected because of the high volume exceeding the collection container capacity – his urine calcium would be less than 250 mg/day. That the stone was not analysed is most unfortunate. I would proceed as I said but get not only the blood tests I mentioned but another 24 hour urine taking extreme precautions to collect a full 24 hours – that might mean two containers or letting the volume go down a bit for a day or two. The high blood calcium could be an important clue or a lab error. Please review these comments with his physicians. Regards, Fred Coe

          • krishna

            Dear Sir,
            We have seen an endocrinologist and as per your suggestion we took test including others as well. As per the report

            Blood Calcium is 9.9 mg per dl Reference is 8.1-10.4 and method used is OCPC
            Hb1Ac is 5.6 percent and Reference being 4.0-6.4 and method used is NGSP certified HPLC
            Parathormone Intact PTH is 224.3 pg per ml and Reference is 15.00-65.00 and method used is ECLIA
            Vitamine D, 25 OH is 8.2 method used ECLIA
            severe deficiency is less than 10ng per ml
            ultra sensitive TSH is 2.83 uIU per ml and reference is 0.27-4.20 method used is ECLIA

            The doctor has not asked for Sestamibi Parathyroid Test.

            The urine test is yet to be obtained

            The result esp. PTH test look scary. Could you please advise what might be the case


            • Fredric Coe, MD

              Hi Krishna, It sounds like the vitamin D deficiency has raised the serum PTH and needs to be treated. Because the serum calcium is at the high end of normal despite vitamin D deficiency there may be underlying primary hyperparathyroidism so as the Di levels go up PTH will come down and serum calcium rise above normal. Your physicians know all this and if this occurs they will see it and act accordingly. The 24 hour urine tests can wait for repletion of the vitamin D. Regards, Fred Coe

              • krishna

                Dear Sir,
                We again took the clinical test and the result were
                Serum Calcium is 10.6 mg/dl when the reference is 8.00 -10.2
                Serum albumin is 4.77 mg/dl when the refernce is 3.8-5.1
                Serum phosphorus is 2.9 mg/ dl when the reference is 3-5

                Urine calcium is 352 mg/24 hrs when the reference is less than 300
                Urine Creatinine is 1529 mg/24 when the reference is 500-2000
                Urine Phosphorus is 759 ,g/24 hrs when the reference is 400-1300

                The serum albumin, calcium and phosphorus was also repeated in another lab. The result are like this
                Serum Calcium is 11.7 mg/dl when the reference is 8.0 -10.4
                Serum albumin is 4.6 mg/dl when the refernce is 3.5-5.0
                Serum phosphorus is 2.7 mg/ dl when the reference is 2.5-4.9
                PTH was 176.40 pg/ml when the reference was 10-65

                The endocrinologist says its a primary hyper parathyroidsm and need to undergo operation. The doctor has referred to ENT and Neck Surgery specialist for the operation.

                As per the radiologist, the sestambi parathyroid scan is not clear and not text book picture.

                Could you please let me know if the test result shows its hyperparathyroidsm and caould you also let me know if ENT and Neck Surgery Specialist are capable of doing this kind of surgery.


              • Fredric Coe, MD

                Hi Krishna, Your serum calcium is high on two occasions in two different laboratories, PTH is high in the same blood whose calcium is high, urine calcium is high. This is good evidence for PHPT. Here are a few possible problems: Were the bloods fasting? Were any drugs being taken that could have produced these changes: High doses of thyroid medication, lithium, diuretics? Are your physicians certain you have no other diseases that could mimic PHPT? That is entirely their responsibility. I cannot assess the skills of a distant surgeon; ENT and neck surgeons are qualified to operate. WHether your surgeon is skilled for PT removal is known only to his/her immediate surgical peers. Regards, Fred Coe

  8. Bruce

    I have been voraciously reading about kidney stone prevention and realize that urologists don’t remotely disseminate a fraction of what you have – drink water with lemon juice and watch oxalate is what I was told. But even with all my reading, there is so much contradictory information out there:
    1. I read that almonds are high in oxalate, and that as almond milk is almond-based, it must be high in oxalate. On the other hand my dietician said that almond milk was not high in oxalate as the oxalate is in the shell which is not in almond milk. How do I reconcile?
    2. I’ve read that the only berry that is high in oxalate is raspberries, but elsewhere that strawberries are high in oxalate and elsewhere again that strawberries are low in oxalate. And I’ve read that stone formers should eat avocados for protein yet elsewhere that they are high in oxalate. And I recently read that you only have to avoid 9 vegetables with high oxalate contents to reduce the risk of recurrent stones. How do I reconcile?
    3. I’ve read that people with kidney stones should include 1000-1200 mgs of calcium in their diets but not via supplements – but I’ve never seen whether food fortified with calcium is good or bad. Is food fortified with calcium like supplements or calcium-rich food?
    4. I’ve read and been told to drink lemon juice (but I’ve also read that frozen lemonade concentrate is high in oxalate at 16 mg/8 oz. (not that I use frozen, but…)). I’ve also read that diet lemonade is low in oxalate – is it the sugar then? I haven’t read that. I’ve also read that potassium citrate may be more effective than lemon juice. Is it? Is it safe?
    5. I’ve read that Stevia is high in oxalate, but processed Stevia is not (wow – processing is good for something). Is this right?
    6. I’ve also read that stone formers should take:
    a. Vitamin B-6 supplements in addition to eating bananas, avocados, soybeans, etc. Correct? But I’ve read that soybeans and avocados are high in oxalate?
    b. Omega 3 supplements (I’ve read to take 1,200 mg/day). Can more hurt?
    c. Magnesium?
    d. Vitamin D (I’ve read both good and bad)?
    e. Vitamin C – limit to 100 mg? 500 mg?
    7. Should stone formers try to make their urine alkaline? I read that animal protein makes the urine acidic which is bad for stone formers and that plant-based diets make the urine alkaline which is good for stone formers – so should stone formers drink alkaline water for the same effect? Does lemon in water make urine alkaline (which I’ve heard from non-medical “health” sites)?

    • Fredric Coe, MD

      Hi Bruce, A lot of useful questions, which I can try to answer. For food oxalate, just read this article which is linked to our oxalate lists. The high calcium in the kidney stone diet – the article this is posted on – protects bone and will lower urine oxalate. It is recommended for all Americans. Calcium can be in foods, added to foods, and if needed one can use calcium supplements with meals. I know nothing about omega 3 supplements, or vitamin B 6 in relation to stones – the scattered articles about them are trivial. Vitamin D is needed to bring your serum levels into the normal range, not about stones. Vitamin C excess can raise urine oxalate. I know of no data favoring attempts to raise urine pH unless stones are made of uric acid, whereupon one needs medicinal doses of potassium citrate. Regards, Fred Coe

      • Bruce

        1. For prevention of calcium oxalate, cystine, and uric acid stones, urine should be alkalinized by eating a diet high in fruits and vegetables, taking supplemental or prescription citrate, or drinking alkaline mineral waters. American Famly Physician (December 1, 2011). Any thoughts on drinking alkaline mineral water based on this study?

        2. Vitamin B-6 can help some hyperoxaluric patients by modifying hepatic oxalate metabolism.   [American Urological Assn Update series]. Intake of vitamins B6 and C and the risk of kidney stones in women. Curhan GC1, Willett WC, Speizer FE, Stampfer MJ. Large doses of vitamin B6 may reduce the risk of kidney stone formation in women. Routine restriction of vitamin C to prevent stone formation appears unwarranted (although this is contrary to what I’ve read elsewhere and the subjects were women without stones…) Any thought on taking B-6 or vitamin C for patients with stones based on these studies?

        3. Researchers have discovered that consumption of only certain oxalate-containing foods is likely to significantly increase urinary oxalate.
        a) The foods reported by at least one group of researchers to cause a significant increase in urinary oxalate include spinach, rhubarb, beets, nuts, chocolate, wheat bran, strawberries, peanuts, almonds, and tea. Not every study has found tea to significantly increase urinary oxalate. [Dayton Children’s Medical Center – 7/14/05]. Also – Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate notes that “Only eight foods—spinach, rhubarb, beets, nuts, chocolate, tea, wheat bran, and strawberries—caused a significant increase in urinary oxalate excretion.” Note strawberries are shown as high here but low in the spreadsheet you sited – and you and Jill say that mushrooms are fine but broccoli is moderately high – mind the portion size, while other sites classify broccoli as low but mushrooms as high in oxalate – who do I believe? Do we really need to limit total oxalate or only the eight foods listed above?
        b) Medical and Dietary Therapy for Kidney Stone Prevention states: Cold-water fish, including salmon, tuna, mackerel, and sardines; walnuts; flax seeds; and canola oil are rich sources of EPA. Why would a kidney stone site recommend walnuts to get EPA oil as walnuts are supposedly high in oxalate? (Korean J Urol. 2014 Dec; 55(12): 775–779. Published online 2014 Nov 28. doi:  10.4111/kju.2014.55.12.775 Zeynep Gul and Manoj Monga1)

        4. For calcium oxalate stones: The ingestion of cranberry juice favorably and uniquely altered three key urinary risk factors, i.e. oxalate and phosphate excretion decreased, while citrate excretion increased. In addition, there was a decrease in the relative supersaturation of calcium oxalate, which tended to be significantly lower than that induced by water alone. [McHarg, Rodgers  BJU Int. 2003 Nov;92(7):765-8. Should we drink cranberry juice, perhaps instead of or in addition to lemon juice (and especially for patients that may have GERD and should avoid lemon juice)?

        5. Oxalobacter formigenes may Reduce the Risk of Calcium Oxalate Kidney Stones – David W. Kaufman*, Judith P. Kelly*, Gary C. Curhan†,Theresa E. Anderson*, January 2, 2008 – is there a probiotic or other way to ensure this is in our systems or is this a non-issue?

        6. Magnesium – Clinical trial evidence does not justify the use of MgO or Mg(OH) 2 as a sole therapy for calcium oxalate kidney stones in a general patient population. However, the addition of magnesium
        to potassium citrate therapy improves outcomes. Clinical trials should focus on patients who are likely to be Mg deficient. Food Science and Human Nutrition, Washington State University. (See also Korean Journal of Urology, June 16, 2014, adding in vitamin B6.) Should stone-formers take magnesium supplements or potassium magnesium citrate (albeit there are nonpalatability issues) if they are deficient in these or otherwise, or not take either?

        7. You and Worcester wrote that at supersaturation below 1 stones dissolve. Does that mean we can make stones disappear? How? I believe you say that only citrate can be modified. I’m not sure how that relates to supersaturation. Also, if a patient may have GERD and shouldn’t have lemon juice in managing GERD, how should a patient address the lack of lemon juice to help avoid stone growth (or should patients drink lemon juice?

        8. A Sorensen study (Jurology) (only of women) suggests that eating a vegetarian diet helps women without stones, but not with stones. I’ve read elsewhere that such a diet is good for you for other reasons. Do you know of studies that show vegetables help people/men (re: stones) for people with stones?

        • Fredric Coe, MD

          Hi Bruce, I am afraid I cannot find your earlier post. Since you are presently listed as having only this one, perhaps that post never made it through.

          As I wrote to you privately via email, there is so much in this comment I cannot really respond in any detail. I will try to make a few comments back, using your point numbers. 1. Raising urine pH is not a treatment for calcium oxalate stones – alkali are used to raise urine citrate. Alkaline water may have too little buffer capacity to alter urine pH. 2.We have what you quote – no recent trials. 3. The issue of food oxalate on this site more or less follows the research of Ross Holmes. I am not a food oxalate researcher. Perhaps he might see this and respond. 4. Many juices will raise urine citrate and thereby lower supersaturations; choice concerns calories and tastes. 5. Oxalobacter’s role in human stones is uncertain, and treatments to date with probiotics have – so far as I know – been unimpressive. 6. The two potassium citrate trials, one with magnesium one without yielded the same results; Mg K citrate was not superior. Magnesium deficiency is not found in routine stone formers but only as a complication of treatments or systemic diseases; repletion of magnesium deficiency is standard medical practice. 7. At a supersaturation below one a crystal will dissolve because fugacity from thermal agitation over weighs the attractive forces on the crystal surface. This is true for all crystals, everywhere, all the time. I am not sure what is being asked in the remainder of the section. 8. The US diet recommendations include 5 servings of fruits and vegetables for all people. Regards, Fred Coe

  9. Lee

    I didn’t see the diet to increase urine citrate. And I know that both are important…but if you had to choose which would cause new stones more, a low urine citrate level or a low urine volume, which would it be? Thanks

    • Fredric Coe, MD

      Hi Lee, Thanks for the important comment. The fruits and vegetables called for in the diet contain the potassium anions – citrate included – that will do as much as diet can do to increase urine citrate. As for volume, that pertains to fluid intake, not foods. Many articles on the site specifically detail how to drink. Here is one. Regards, Fred Coe

  10. Denise

    I’m 56 and just recently diagnosed with 2 large kidney stones. This was discovered due to blood in the urine, but so far I’ve not experienced pain so I’m not taking any medical treatment. I’ve begun drinking apple cider vinegar/ & lemon juice with water 2-3 times per day, increasing my water intake, and now I will cut down on some of the high oxalate foods you list. This is difficult because I have always eaten what I consider to be a healthy diet that includes lots of greens, veggies, nuts, low carb and low meat. I don’t know what type of stones I have because I haven’t passed any. The low oxalate diet doesn’t seem like a great diet for overall health but I will try to find a compromise. A couple of questions: I grow raspberries and blackberries and eat them regularly all year with yogurt. Are blackberries also high oxalate? Are all types of nuts high oxalate? I have heard of a dietary supplement recommended by some naturopaths as a cure and prevention for kidney stones. It’s called “Chanca Piedra” which translates to “break stone” and is a traditional herb which has had some good reviews for dissolving kidney stones. What is your knowledge of this? It would be wonderful to have more research on it. Thank you.

    • Fredric Coe, MD

      Hi Denise, Diet is a means of stone prevention but not sufficient always, and hard to direct without a proper evaluation. Before launching into treatment, take a look at a good way to be evaluated, and get through the steps needed. As for Chanca Piedra I did review the material for another comment and found no evidence to support its use. Regards, Fred Coe

    • jill

      Hi Denise,
      All nuts are on the high list. The herb has not been proven to work so we cannot speak of it for stone prevention. Blackberries are lower and raspberries are high. You have the low oxalate list I gave on the FB page, so you can see what is low for fruits.
      It is a shame that many high oxalate foods are healthy, but you can still incorporate them into your diet if you eat enough calcium (like raspberries in your yoghurt) with the oxalate containing food.
      Hope this helps-

  11. Marc

    Hi Dr. Coe,
    My Litholink labs are below and some meaningful changes. I started taking 12.5 mg after the second lab results and have been taking for 5 months now. i take no calcium supplements. any thoughts for me? I read through your site and greatly value your insights.

    Stone Risk Factors /Cystine Screening:
    DATE Vol 24 SS CaOx Ca 24 Ox 24 Cit 24 SS CaP pH SS UA UA 24

    10/03/16 1.66 14.70 372 60 956 1.67 5.915 1.09 0.783
    04/04/16 1.59 9.46 334 35 991 1.74 5.809 1.13 0.626
    11/24/14 2.04 9.02 289 48 815 0.82 5.756 0.91 0.602

    Dietary Factors
    DATE Na 24 K 24 Mg 24 P 24 Nh4 24 Cl 24 Sul 24 UUN 24 PCR
    10/03/16 196 74 170 1.092 46 214 59 13.68 1.1
    04/04/16 98 50 200 1.212 29 98 35 12.06 0.9
    11/24/14 206 84 109 1.162 45 246 36 1 1.10 0.9

    DATE WEIGHT Cr 24 Cr 24/Kg Ca 24/Kg Ca 24/Cr 24
    10/03/16 97.5 2647 27.1 3.8 141
    04/04/16 98.9 2233 22.6 3.4 149
    11/24/14 95.7 2323 24.3 3.0 124

    • Fredric Coe, MD

      Hi Marc, Of course I can only offer some technical points as it is your physicians who are responsible. Your sodium intake is high, so urine calcium is high, your urine volume is low, your urine oxalate is high and your SS for CaOx and CaP are high. The ideal your physician no doubt seeks would be to lower the sodium to at least the US upper limit of 100 mEq (2300 mg) which would lower the urine calcium, and raise your diet calcium to 1200 mg – with food ideally so as to lower urine oxalate and preserve your bones, avoid refined sugars that raise urine calcium and when all this is in place perhaps get better control. DId I mention – you need double the urine volume! Now this is only technical, so be sure and discuss these matters with your physicians. Regards, Fred Coe

  12. Susan

    Many nuts are high in oxalate, but also contain a fair bit of calcium. To what extent does the calcium in common nuts (peanuts, almonds, cashews, etc.) mitigate the presence of oxalate?

    • Fredric Coe, MD

      Hi Susan, a wonderful question. I do not know the answer as I have not found a paper in which nuts were used in a trial and urine oxalate measured. I suspect like spinach nuts have calcium mainly bound to oxalate, so the amount of calcium is too small to prevent oxalate absorption. A typical liberal oxalate diet is 200 mg/day, whereas a proper calcium intake is 1,000 to 1,200 mg/day so the calcium over reaches the oxalate by 5 to 6 fold. Regards, Fred Coe

  13. Sally Likens

    Dr. Coe,
    My sister was recently diagnosed with stage 4 kidney disease. Her nephrologist called it oxalate nephropathy. She had a kidney biopsy which found oxalate crystals in the tubules of her kidney. My brother has had one calcium oxalate kidney stone. How would I find out if I need to be on a low oxalate diet? Also, do you have any suggestions as to where my sister could find a nephrologist with expertise in the area of oxalate nephropathy? Her nephrologist in Tulsa, OK told her that the large nephrology group practice he is in only sees a few cases per year. Thanks!

    • Fredric Coe, MD

      Dear Sally, I apologize for the delay. It sounds as if she has primary hyperoxaluria and has had the misfortune to lose her kidney function. The correct treatment is usually combined liver kidney transplantation, and this is a very high level kind of treatment. The Mayo Clinic has a rare disease registry and the part for her is the hyperoxaluria center. Dr John Lieske is a key physician in that program and at Mayo. I strongly advise she contact them. Regards, Fred Coe

  14. Thomas Hollomon

    Is unsweetened almond milk, which contains approximately 30 calories per serving, an acceptable alternative to skim milk?

    • jharris

      Hi Thomas,

      Sure it is, if you are not watching your oxalate. Almonds are very high in oxalate, so be careful if you need to lower oxalate in your diet.

  15. Jeanne E. Heinen

    Dear Dr. Coe,
    I am confused about your recommendation re the kidney stone diet, as far as calcium intake is concerned. I was diagnosed with hypercalciura perhaps ten years ago when I kept getting UTIs and other discomfort while taking calcium supplements because of osteopenia. (I had had one rather large calcium based stone some years before and since then only smaller ones). During the time I was diagnosed with hypercalciuria I went from osteopenia to osteoporosis. I was told that too much calcium was detrimental, that I should not have more than 900 mg total calcium (food and supplements) daily, to avoid oxylates, to drink a lot of water, and to take a diurectic (started with one and then was switched to chlorthalidone). It was explained to me that with hypercalciuria, calcium is drained out of my bones and straight into my kidneys. This info is from two urologists as well as two bone health specialists I have seen. But you are saying to take MORE calcium; thus the confusion. Please advise.
    Thank you,
    Jeanne Heinen

  16. Mark

    A calcium oxalate stone former, recent tests showed normal blood results including calcium, sodium, potassium and PTH; with only Vit D indicated as low. High urine calcium (370 mg/d) and oxalate (55 mg/d) were coupled with normal citrate (470 mg/d) and sodium, slightly acidic pH (5.5) and good urine volume (>2.5 L/d). In addition to diet changes to reduce oxalate and increase calcium consumption at meals (either via food or low-dose supplementation with Vit. D), potassium citrate has been suggested in effort to promote urine calcium binding, inhibit crystallization and increase pH alkalinity. Cost aside (which is not imposing in Canada), are there any other reasons not to include potassium citrate as part of a stone prevention regimen (eg. side effects/risks) and what is the very lowest (starting) dose that might begin to show efficacy? Look forward to your reply.

    • Fredric Coe, MD

      Hi Mark, You seem to have idiopathic hypercalciuria and perhaps low calcium diet fomenting hyperoxaluria. The article you are responding to seems to be about perfect for you and, since I have offered this as a general principle, I offer to you the idea that you might want to establish all of the parts of the diet before using medications to see what is really more needed. You say urine sodium is normal, I am concerned that ‘normal’ is too liberal. So, try the diet. retest, and discuss with your physicians what more you need. Of course, discuss this note with them before taking action, as we are about 1,000 miles and a border apart and there may be lots of things about your condition I do not know. Regards, Fred Coe

      • Mark

        If the results of any prevention protocol equal efficacy times compliance, I would think that potassium citrate would only enhance diet change outcomes (or help mitigate any adherence challenges) with a favourable risk-to-benefit ratio. When one wishes to effect metabolic change to avoid the potential pain/downtime of a future stone episode, diet change and re-testing alone seems a long waiting game; particularly given diet change requirements are often seismic and compounded by the reliability of food composition lists. Further, I understand that shifting pH more alkaline (to 6-6.5) mitigates calcium oxalate stone formation, but is very difficult to achieve solely by diet. Again, cost aside, are there risks in using potassium citrate (where metabolic results support) that outweigh the benefits and inhibit you from recommending it as a first-line strategy in conjunction with diet change?

        • Fredric Coe, MD

          Hi Mark, Change of diet is so fundamental I favor putting all attention to it and perhaps that creates what seems to be dawdling. But I long ago published what happens in even my own clinic: Drugs, no stones, stops coming in, drugs stopped, new stone, back to the clinic. The loss rate from treatment is about 3 years mean time, and is log linear with time. This knowledge has had a large effect on my approach, and I aim for a change in life – diet and fluids – to which I can add medications as needed. It is a more solid way but of course a double blind randomized trial of one way vs another is almost impossible to imagine. You are a thoughtful and interesting person, and I appreciate your remarks and take them seriously. Regards, Fred Coe

          • Mark

            Diet changes aside, can low doses of potassium citrate confer any benefits? With potassium citrate available OTC in tablet dosage of 99 mg (ie. .92 mEq), I am wondering if 6-10 tablets/day (approximately 5-10 mEq/day) would offer any ability to increase urine alkalinity and inhibit crystallization? Cheers.

            • Fredric Coe, MD

              Hi Mark, Good question, but diet changes are never aside as they are the base for treatment. The best way to prevent stones is to follow a program, and here is one that will work. YOu have to identify the key problems and fix them. Maybe citrate is a problem for you, maybe not. Diet and fluids do a lot to correct urine chemistries so the dosages of meds can be less, too. Take a look and see if this approach works for you. Regards, Fred Coe

  17. Gregory Hubert

    Hello Dr Coe,

    I am grateful for your guidance to me to increase my calcium intake through skim milk, as my changing to a vegan diet had been a primary factor in my kidney stone problem. Please I ask if you might offer direction and suggestions for those of us who are animal-free in our protein intake. Is anyone researching the best forms of plant protein that we might use?

    Thank you.

    Greg Hubert

  18. Kally

    This is a fantastic list, thank you both. How does greek yogurt fit in the diet? Is it low or moderate in oxalate?

  19. Ricki Linksman

    Dr. Frederic Coe one of the nation’s leaders in kidney stone research from the University of Chicago Hospital is brilliant and in his article on the Kidney Stone diet has made a phenomenal contribution to the field of kidney stone prevention. His recommended kidney stone prevention diet is a masterpiece and a guide to live by to manage kidney stones and idiopathic hypercalciuria for optimal health. Dr. Coe makes a complex subject easy to understand for non-medical readers. This information should be disseminated widely to the public to help prevent the suffering kidney stones brings in a safe, natural, and easy-to-live by manner. Thank you Dr. Coe and Jill Harris.

    • jill

      Hi Ricki,

      Thanks for the shout out. We are on a mission to help make these dietary changes as easy as possible. We understand that making lifestyle changes can be challenging and with all the contradictory info on the web it makes it even worse. You all deserve easy to understand AND backed by research.

      Anything we can do to make your lives a bit more manageable is what matters most to us.


  20. Michele

    Thanks for the easy and concise approach to implementing the “kidney stone” diet. I keep learning as I get older and continue to maneuver my way through this disease. Had my fifth ESWL in Feb. of this year and it was a success. I do have hyperoxaluria and I know that I was eating a very high sodium diet my entire life. It’s a daily struggle not eating many oxalate rich foods and cutting the sodium. I do drink a lot of water however and use the Minute Maid frozen lemon juice in some of it. It’s pure with no additives. Also take Theralith XR and it has brought my urine PH from 5.5 to 7. Thanks so much for all of your well thought advice, it has truly made a difference in how I approach each day.

    • Fredric Coe, MD

      Hi Michelle, Raising your diet calcium to 1,000 or 1,200 mg and timing the calcium to go with foods that contain oxalate should be very effective in lowering urine oxalate. But the low sodium is essential or else urine calcium may rise overly. With the high calcium you may be able to increase your use of foods that have some oxalate. Regards, Fred Coe

  21. Yvette Berisford

    What is the role of stevia in the kidney stone diet? Does the consumption of 1/2 gallon of Crystal Lite Lemonade (made from the powder plus Smart Water) per day help to prevent kidney stones from growing or ‘sticking together’ OR should the lemonade be deleted from my diet? Stevia, in moderation, is the only sweetener that I use. I started using this lemonade because it was recommended in the book, No More Kidney Stones by Gail Savitz and Stephen Leslie. Thank you, I am still ‘digesting’ all of your articles — keep them coming!

  22. Kim Gallagher

    Great article. Does a great job of simplifying the dietary “guidelines” for stone prevention.


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