IMG_2303Jeff, a reader of this site, suggested this topic and I realized it was one that I should have written long ago.

You can make sense of all those numbers in the 24 hour kidney stone reports.

You can use those numbers to understand how things stand with you.

Reading the numbers can help you achieve your best possible chance at stone prevention – which is the only reason all those lab tests were done in the first place.

This article deals with calcium stones. A second one will cover uric acid stones.

Be Sure You Have Been Screened For Systemic Diseases

Your physician does this part. But even for systemic diseases stone risk is gauged in the urine so you can read along and assess how prevention is going.

Units of 24 hour Urine Measurements


Because excretions of stone risk factors are in amount per 24 hours, we need the time of the collection. You provide the beginning and end times for the collection, in minutes and hours, and the laboratory corrects all excretion values to amounts in 24 hours.

For example, you start a urine collection at 7 am and complete it at 5 am the next morning. The measured total time is 22 hours. If the volume is 1.5 liters, the volume ‘corrected’ to 24 hours is 1.5 liters x 24 /22 (1.09) or 1.636 liters/24 hours.

It is obvious that the less ‘correcting’ the better, because the ‘correction’ assumes that every hour is the same as every other hour, which is not likely. So you want to collect as close to 24 hours as possible. If your time is below 22 or above 26 hours throw it away – no cost – and do another.

I am sure this is an unnecessary comment but sometimes people forget that a urine collection begins by emptying the bladder, writing down the time, and discarding the urine. Here and there people add it, making the real collection from whenever the bladder had last been emptied.

Volume per 24 Hours

Urine volume is measured in liters (L) or milliliters (ml). A milliliter is 1/1,000 of a liter, so there are 1,000 ml in a liter. One liter is 1.06 quarts. The laboratory measures the total volume of urine if you send or bring it. Often you will read the volume yourself, off of a collection container.

Because excretion rates like calcium, oxalate, citrate, and uric acid are calculated by multiplying their concentrations by the 24 hour volume, mistakes in timing, collection, or measurement of volume will make the results less valid. You provide the collection times, assure all the urine has been collected, and even may measure the volume, so quality is under your control.

Excretion Rates

Urine creatinine, calcium, oxalate, phosphate, and citrate excretions, are in milligrams (mg) or grams (gm) per 24 hours. A mg is 1/1,000 of a gram. An ounce contains 28.3 gm.

Urine sodium is measured in millimoles (mmol) or milliequivalents (mEq)/24 hours. Atoms, like sodium, each have a weight made up mainly of their constituent protons and neutrons. One mmol of sodium is 23 mg.

Some atoms like calcium have two charged sites which can bind to other molecules or atoms. They are often measured in milliequivalents (mEq) which is the weight times the number of sites. Sodium has only one, so mmol and mEq are the same.

Molecules like creatinine and oxalate have weights made up of their constituent atoms.

Conversion of Units

Some laboratories report in mmol or mEq. You can convert your lab report if it differs from mine. I will be using L for urine volume, mg for urine creatinine, calcium, oxalate, and citrate, and mmol for urine sodium. Here are the conversions:

Creatinine; 113 mg/mmol

Calcium: 40 mg/mmol; 20 mg/mEq

Sodium: 23 mg/mmol or mEq

Oxalate (oxalic acid): 88 mg/mmol; 44 mg/mEq

Citrate (citric acid): 189 mg/mmol

Direct Measurements

Acidity or alkalinity are measured in pH – no units. It is a logarithm to the base 10 so a change from 6 to 5 means a 10 fold increase in acidity, from 6 to 7 a ten fold increase in alkalinity.

Supersaturations are calculated from urine concentrations. The one we use here is the ratio of the concentration dissolved in urine of each of the three important stone forming salts, calcium oxalate, calcium phosphate, and uric acid divided by their individual solubilities at body temperature. Values below 1 mean crystals will dissolve. Values at one mean crystals will neither grow nor shrink nor form. Values above 1 mean crystals can form and grow. Being a ratio it has no units.

Is The 24 Hour Urine Valid?

Urine creatinine

Like all 24 hour excretion rates, that for creatinine is calculated from the concentration, measured volume, and collection time.

Because muscle cells make almost all the creatinine lost in urine any two urines you collect will have about the same amount of creatinine in them. A more than 20% variation between two urines suggests an error in one collection. If there are many collections, most creatinine excretions will line up pretty well, and an outlier – too high or low by more than 20% of the average for all the collections will stand out.

When a urine stands out as different from prior collections, I say it is best to repeat it. If there are two, use the one that seems more correct.

‘More correct’ is judged by expected amounts of urine creatinine. For men, one expects about 18 – 24 mg/kg body weight; for women, 16 – 22. A urine far out of those ranges is suspect. In people who have a high body fat percentage the ratio can be as low as 12 mg/kg/day, and people who have little body fat and a high muscle mass can be as high as 30 mg/kg/day.

Conditions of Collection

Did you eat and drink as usual, or show off? Had you ‘improved things’ since a recent stone so your collections reflect new habits and not those that led to the stones? Every collection is a one day frame out of a movie that is running 365 frames a year, so if these few days do not reliably represent your average life, their results will inevitably mislead you and your physicians and falsify what you came to do.

Reading the Results

Urine Volume

Curhan and colleagues have linked new onset of stones to urine volume in three large cohorts reviewed in our other articles. Take a look now. The graph is on page 2 of the article. Risk is on the vertical axis, and urine volume is on the horizontal axis. When red shows above the line at 1 it is above normal.

Risk is low above 2.25 liters/24 hours. But the day is long and the 24 hour urine is an average, so for insurance it is best to overshoot so the low times are still not too low. I would say 2.5 – 3 liters liters/24 hours is ideal.

Urine Calcium

Stone risk increases with urine calcium excretion above 200 mg/day in men and women – take a look. The calcium risk is at the upper left corner of the graph.

If you have above 200 mg/24 hours you have ‘hypercalciuria’, a high enough calcium to pose risk of stones – and also bone disease. There are many causes of hypercalciuriaThe commonest is simply a genetic tendency, called idiopathic hypercalciuria. ‘Idiopathic’ means your physician has ruled out any of the other causes of hypercalciuria.

You lower urine calcium in idiopathic hypercalciuria with reduced diet sodium, avoidance of sugar loads, and medications if needed. You compare treated to untreated excretion to see how well the treatment worked.

Urine Sodium

Urine sodium is essentially the diet sodium intake. Because urine losses can lag intake when intake varies sharply, urine sodium is a good estimate of the average over 3 – 4 days. If you tried to lower your diet sodium to 100 mmol/24 hours, 2,300 mg intake, and you find 200 mmol/24 hours, you can be sure that your average intake is on average twice what you desired.

Suppose your urine calcium is 250 mg/24 hours, urine sodium 200 mmol/24 hours – twice the upper limit of diet sodium in the US and above the optimal value of 65 mmol (about 1,500 mg/24 hours). You would want to lower your diet sodium. Suppose your urine sodium was already 65 mmol/24 hours and urine calcium was 250 mg/24 hours; you would want to take other steps like thiazide diuretics or potassium citrate.

What if your urine calcium is 450 mg and your urine sodium is 200 mmol? Sounds like a bigger problem, but it is not. When urine calcium is higher the slope dependency of urine calcium on urine sodium is steeper, so the same reduction of sodium could bring urine calcium quite a way down.

If you lowered diet sodium and there is no change, do not assume the test is wrong. Check the creatinine values – do they match? If so, you have not lowered your average sodium intake. Sodium is an atom and you are not a cyclotron; you cannot make sodium or destroy it.

Sugar Loads

Given to people with idiopathic hypercalciuria they cause a rapid rise in urine calcium and supersaturation. The 24 hour urine will tend to underestimate this because of averaging throughout the day.

Thiazide Diuretics and Potassium Citrate

These drugs come after diet changes have not proven sufficient and are added to the diet changes.

Urine Oxalate

Stone risk increases with increasing urine oxalate and if the risk ratio is not as high as for calcium risk appears at very low levels of excretion – above 25 mg/day. In general, high urine oxalate comes from high oxalate diets, low calcium diets, or the combination of high oxalate and low calcium together. Therefore treatment is dietary. Excellent food lists are in this site – linked from the oxalate diet article. Rarely, urine oxalate is raised from a hereditary overproduction state – primary hyperoxaluria. Likewise, bowel diseases can raise urine oxalate. These are complex conditions and diet alone is rarely enough.

If urine oxalate is high and you have corrected both your diet oxalate intake and added significant diet calcium, you may have some form of genetic or acquired oxalate overproduction or an otherwise inapparent intestinal absorption problem.

Urine Citrate

Citrate is a powerful force against calcium stones. It binds calcium in a soluble complex. It interferes with calcium crystal formation and growth. Low urine citrate is a risk factor for new stone onset – bottom left panel of the graph. Above 400 mg daily there is no extra risk of stones in men or women, so ‘hypocitraturia’ means a urine citrate below 400 mg daily.

If you begin taking, as an example, four 10 mEq potassium citrate pills a day – 40 mEq, that extra 40 mEq of potassium should appear in the urine. If it is not there, the pills may not be delivering the medication into the blood from the bowel. The urine pH should rise because citrate imposes an alkali load. If it does not and the urine potassium does rise, you may need more of the medication.

Urine ammonia – I will cover this in the second half of this two part article – is a major way the body removes acid, so when you take citrate ammonia excretion should fall. If it does not fall, and urine potassium rises perhaps your pills are potassium chloride – the pharmacist switched from what was prescribed.

Strangely, the urine citrate itself does not rise in everyone even when potassium and pH rise and ammonia falls.

Urine pH

A low value – below 5.5 poses a risk of uric acid stones. A high value, above 6.2 raises calcium phosphate supersaturation and risk of calcium phosphate stones. Potassium citrate can raise urine pH; there are no medications to lower urine pH except methionine and ammonium chloride and these are not usable for stone prevention because they will increase urine calcium and pose a risk of bone mineral loss.

Urine Supersaturations

Get Them

If there are no supersaturations, ask that your samples be processed by a vendor that provides them. Supersaturation is the driving force for crystal formation and growth, and invaluable for monitoring stone prevention.

Relate Them To Your Stone Crystals

There will be three supersaturations: Calcium oxalate, calcium phosphate, and uric acid. Inspect the ones related to your stone crystals. For calcium oxalate both calcium oxalate and calcium phosphate supersaturations matter. If calcium phosphate, that one matters most. If pure uric acid, it is uric acid supersaturation.

Reduce Them

One should not compare values in a stone former to values in normal people, who often have urine supersaturations as high or higher than those of stone formers. Active stone formation means supersaturation is too high for you whatever the value may be and needs to be lower. You reduce your supersaturations by increasing urine volume and reducing excretions of calcium and oxalate, or raising excretion of citrate without undue increase of urine pH. That is why we make these measurements.

Compare Then to Now

Compare you now to you before your most recent fluid and diet intakes or medications: If they have fallen, things are going well; if they have risen things are not going well. If stones are still forming, supersaturations need to be lower. If there have been no more stones and supersaturations are stable, stand pat. If supersaturations are below 1 and stones are still forming, the urine samples do not properly represent your real life.

A Good Schedule

When? I like two 24 hour urines before treatment – it gives a sense of averages. After treatment has begun – diet changes, fluid goals, lifestyle, it is important to get another. The timing is up to patients: You know when something has changed, or ought to have changed, and need to be sure it has indeed changed in the right direction. It goes on like that until treatment is reaching its goals – lowering supersaturation by at least half – after which once a year is a good idea.


203 Responses to “HOW TO READ YOUR KIDNEY STONE LAB REPORT – Calcium stones”

  1. Jessica

    Hi Dr. Coe,
    I was poisoned by multiple heavy metals by unknowingly drinking a health product that was contaminated with toxins in Nov 2018. I was 37 and healthy. I noticed crystals in my urine ever since the incident. All shapes, sizes, colors that I can see with my naked eye. I had labs done March 2020 by the Mayo Clinic. This 1 yr and months later since I drank toxins. Can you please help interpret them. They are a 24 hr urine.
    Calcium oxalate 1.36DG
    Brushite 0.22DG
    Hydroxyapatite 5.55DG
    Uric acid is -2.66DG
    Sodium Urate 2.65DG
    Sodium, random U 152mmol/L
    Calcium random 5mg/dL
    Calcium/creatinine ratio 0.02mg/mg
    Magnesium random 20mg/dL
    Magnesium/Creatinine ratio 0.094mg/mg
    Potassium random 59mmol/L
    Chloride random 91mmol/L
    Phosphorus pediatric random 77mg/dL
    Phosphorus/Creatinine ratio 0.36mg/mg
    Sulfate random 229.9mg/dL
    Citrate excretion 35.9mg/dL
    Citrate/creatinine ratio 0.17mg/mg
    Oxalate pediatric random 0.59mmol/L
    Oxalate concentrations 51.93mg/L
    Oxalate/creatinine ratio 0.02mg/mg
    pH random 6.8
    Uric acid random 51mg/dL
    Uric acid/creatinine ratio 0.24mg/mg
    Creatine random 212mg/dL
    Osmolality random 906mOsm/kg
    Ammonium random 25mmol/L
    Thank you kindly for your help!

    • Fredric L Coe, MD

      Hi Jessica, I cannot do it properly. You need to multiply the concentrations by the liters/day of urine which will given the amounts of material lost in the urine daily. These are all concentrations. The only measurement I can interpret well is your urine calcium which is given in mg/mg of urine creatinine. Usual values for urine calcium are per gm of creatinine so your value is 20 mg/gm creatinine, a low number. This could arise from many reasons – low calcium diet, vitamin D deficiency, reduced kidney function. Without serum values I cannot know the latter. Moreover, you should gather some of the urine crystals and get them analysed – what they are made of may be important. Regards, Fred Coe

  2. Vince

    Hello, Dr. Coe, I’m posting my results below and was curious on what they mean.

    Urine Volume 3.16
    SS CaOx 2.61
    Urine Calcium (mg/day) 118
    Urine Oxalate (mg/day) 35
    Urine Citrate (mg/day) 552
    24 Hour Urine pH 6.141
    SS CaP .29
    SS Uric Acid .31
    Urine Uric Acid (g/day) .611
    Can you please tell me what it means?

    • Fredric L Coe

      Hi Vince, Strictly by numbers stone risk is very low. In fact you have no obvious abnormal results. But lab results need a context. So what I say is just that – the numbers are not pointing to anything abnormal. Best, Fred Coe

  3. Stuart Barnes

    Dr Cole,
    I’m about to go and get my second cluster of stones lasered in a few weeks time. This will be the second time on 6 months. The only irregular findings in my 24hr urine testing was that my Oxalate levels were high. I understand that I have change my diet to consumer fewer oxalates, and also increase my calcium intake with meals. I have spoken to my specialist, and GP re some severe tiredness that I’ve been experiencing (also experienced this leading up to the kidney stones being lasered in the past), both my GP and urologist seems to think that the tiredness and kidney stones are not linked.
    However my GP has noted that I have a Vitamin D deficiency, and has prescribed some Vitamin D supplements. However, I am under the impression that Vitamin D supplements can increase the risk of kidney stones! Clearly I do not need a higher risk of stones. Any ideas?

    • Fredric L Coe

      Hi Stuart, Be sure about how high the oxalate is – it should be well below 80 mg/d. Vitamin D deficiency needs treatment, and such treatment should not raise urine calcium unduly. But sometimes vitamin D deficiency masks idiopathic hypercalciuria or even primary hyperparathyroidism, so be sure and check blood and 24 hour urine when your D levels are normal. Regards, Fred Coe

  4. Ali Fouda

    Dr. Coe, My son is 12 years old, and a random sample ( not collected sample) of urine was analyzed. The results were as follows:
    1- Urine Oxalate ( Colorimetric) = 0.86 (without reference rang)
    2- Urine Citrate = 0.42 mmol/L (without reference rang)
    3- Uric Acid – urine = 1088 (reference range: 446 – 2944)
    4- Urine Calcium =1.68 (reference range: 0.5 – 4.37 )
    5- Urine Creatinine = 3470 (reference range: 5300 – 22100 )

    in addition to, other blood analysis as follows:
    1- CA – Calcium = 2.35 (reference range: 2.12 – 2.52 )
    2- CREA – Creatinine =47 (reference range: 53 – 115 )

    could you please evaluate the results
    Is there a deficiency in Urine Citrate level?

    • Fredric L Coe

      Hi Ali, I am afraid these measurements are not interpretable by me. You need the full 24 hour day so one can compare to normal children. Likewise, you do not give units. Is the creatinine in mg/l, mmol/l, or are these total amounts in the collection. Regards, Fred Coe

      • Ali Fouda

        thanks for your cooperation, creatinine in µmmol/l

        • Ali Fouda

          how can calculate the urine citrate/creatinine ratio mmol/mmol

          • Fredric L Coe

            Hi Ali, I suggested you might like to send along all the measurements with units and I can try to help. Fred

      • Ali Fouda

        Updated, new analysis for random urine creatinine is 100 mg/dL

        • Fredric L Coe

          Hi Ali, But all the other units? Can you repost with all the tests showing their units? Fred

  5. T boehs

    My us came back saying calcium oxalate crystals. Rare abnormal. What does that mean?

  6. Norman Dobson

    Dr Coe,
    Thank you for this website! I am a 59 year old male. 6’@ 148lbs, BP119/75, no meds yet. Passed first Kidney stone(Calcium Oxalate Dihydrate 20%, and Calcium Oxalate Monohydrate 80%), in October, 2019, 4mm from right kidney, still have 2mm and 1mm in left kidney. Ten days of agony so I am highly motivated to not repeat this experience. Urologist had me do one 24 hour urine eating and drinking as I had before passing the stone. When I was at the follow up appt. The doctor told me I had Hypocitraturia and low urine volume, in addition he said I eat too much animal protein and asked if I had ever been diagnosed with Gout. I didn’t see the actual numbers until I had found your web site and read your page on going over the results. The doctor prescribed 15mEQ Urocit-K 1 at breakfast,1 at dinner, plus produce >2L urine/day, eat less animal protein. The urine production part I am doing and cutting back on animal protein and realized I was eating ~3000mg sodium/day, now I have cut back there to ~2200/day, but I have had Irritable Bowel Syndrome most of my life and taking potassium citrate makes me feel sick all the time. I thought I could get used to it but haven’t been able too so far. I will try for a few days to a week and then need a week to feel better. I called about this and was told to stop and make an appointment. I have a follow up in March. Would going down to 5mEQ/day of the potassium citrate possibly let me get used to it? and my other questions: With my urine PH of 6.6 and supersaturation of brushite does it make sense to take the citrate? What in these numbers indicate Gout? In your page on Kidney stones and Middle Age, you list change in diet, well with IBS in the last 5 years or so I saw how much better I felt in eating a high protein low carb diet, but clearly it wasn’t good for my kidneys, so I have moved towards your recommended diet as best I can. For the acid load, are dairy products (cheese and yogurt) considered animal protein? Is there anything else you see in these numbers that I should bring up with my doctor at my next appointment? I will be requesting a second 24 hour sample since I really have changed my diet. Thank you, Norman
    The results are below first for serum drawn the morning I dropped off 24hour sample, so I had not fasted (if that was important to the results)
    Sodium 141
    Postassium 3.8
    Chloride 102
    Carbon Dioxide 31
    Creatinine 0.71
    eGFR non-Afr American 102
    Calcium 9.8
    Magnesium 2.1
    Phosphate (as Phosphorus) 2.4L ref. 2.5-4.5
    Uric Acid 3.7L ref. 4.0-8.0
    24 hour URINE Diagnostic—Urine Volume 1.55 liter low
    PH Urine 6.6
    Calcium 228mg/day
    Oxalate 18mg/day
    Uric Acid 501mg/day
    Citric Acid 293L >320mg/day
    Sodium 155mEQ/Day
    Sulfate 20mmol/day
    Phosphorus 682mg/day
    Magnesium 98mg/day
    Ammonium 40mg/day
    Potassium 32 mEQ/day
    Creatinine 1075 mg/day
    Are these SS indexes-> Calcium Oxalate 1.30
    Brushite 3.55H,
    Sodium Urate 2.61H,
    Struvite 5.67

    • Fredric L Coe

      Hi Norman, Your stone was 80% calcium oxalate monohydrate meaning a that calcium does not predominate greatly over oxalate. Your urine values are all normal except the oxalate is frankly so low I doubt the quality of the vendor who did the work. However the urine creatinine is also low for a mid life man, even one of very modest weight. Perhaps the urine is under collected. The ratio of urine calcium to urine creatinine – in grams – is very high, at 212, so I wonder if you have genetic hypercalciuria and an under collected urine that is deceiving us. That could also account for the faulty urine oxalate and low seeming urine citrate. I would do another urine, collect it fully, expect a lot more creatinine – about 1300 mg for your size if you are fit and not fat. That will clarify matters. As for potassium citrate, you probably have normal urine citrate with a full collection. Regards, Fred Coe

  7. Adrian

    Dr. Coe, I’m a 59 year old male and just recently discovered I had kidney stones. I had a large 1.8cm stone in one kidney and two smaller 3-4mm stones in the other. Had two lithotripsies to reduce the large stone. The stones were assessed as Calcium Oxalate between the lithotripsy sessions so I had made changes to my diet at that point. After the second lithotripsy and then having the stent removed I had my follow up. No new stone formation and we decided to do the 24 hour collection. My results came back and everything associated with Calcium stones was within the limits (calcium 124mg/day, oxalate 44mg/day, sodium 176 mEq, Calcium Oxalate SS .73). However, my Uric Acid was 774mg/day and Uric acid SS 1.59 and Brushite .28. Urine volume was 2.5L, PH 5.8, Phosphorous was high at 1145mg/day, Potassium 68 mEq/day, Ammonia 37 mEq/day, Creatinine 1850mg/day, Citric acid 637mg/day. The report suggested I have Hyperuricosuria. So while I’m pleased I have my Oxalate issue under control I’m a little perplexed about the uric acid issue. I’ve read your article on dealing with Uric acid stones but not quite sure specifically what I should do at this stage. Any insight and/or advice is appreciated.

    Thank you,

    • Fredric L Coe

      Hi Adrian, You have calcium oxalate stones, and your urine oxalate is quite high at 44 mg/d. Risk from urine oxalate begins at 25 mg/day. Uric acid stones are not present, and the borderline urine uric acid excretion is trivial. Common reasons for normal urine calcium and high urine oxalate include low diet calcium, as well as high diet oxalate. I would consider these possibilities. As well, conditions of your collection may not mirror those that caused your stones. Perhaps your life style or diet were quite different before now. Regards, Fred Coe

      • Adrian

        Dr. Coe thanks for your response. I did change my diet after the diagnosis of calcium oxalate stones but outside of the daily consumption of nuts, occasional spinach and potato it wasn’t that high in oxalates. I’ve upped diet calcium through dairy conisderably (1 cup of yogurt/cottage cheese & 2-4 oz of cheese daily plus vitamin supplement). I manage sodium intake as well. My fluids intake was always around 2-2.5 L but I’ve increased it to 3+ L. I’ll continue with tightly controlling the diet oxalates, consuming diet calcium and keeping the fluids up.

        • Fredric L Coe

          Hi Adrian, But be sure to check a new 24 hour urine to be sure about your stone risk. If you increased diet calcium without lowering diet sodium urine calcium might rise and increase stone risk. You do not mention lowering diet sodium – a crucial step. Regards, Fred Coe

  8. K Brown

    I had 2 24-hour tests. One that was specific to kidney stone risk (which was 10 days ago and I don’t have the results from that one yet), and a regular 24-hour one which I got the results from this morning. Volume was 1.04L so I know I have to double my fluid intake. I had high Calcium oxalate (3.08), high sodium urate (2.44), low citric acid (249), low Mag (56), high brushite (5.87). Report says suspected problem: hypocitraturic nephrolithiasis. The one that I can’t figure out is the brushite and what that means. I’m already on a restricted diet: no gluten, dairy, soy, turmeric, chocolate, black tea, mango, tree nuts, peanuts, grapefruit because of allergies, my weight is normal (actually a little under), I’m 51, female. And I just started getting kidney stones Oct 2018. I’ve had 6 since then. My father has had about 20, and my older brother has had 4. I also have chronic UTIs (probably 150-200 in the last 20 years) and wondering if that has any effect on the stone formation.

  9. Lesley Howell

    Hi. My daughter has been doing urine test once a week. Can you help me with results?
    Leukocytes esterase ur 3 +
    Calcium oxalate crystals 207 up
    Urobilinogen .2mg
    Hydaline cast 1.0
    Thanks oh she is 7

    • Fredric L Coe

      Hi Lesley, I suspect she has genetic hypercalciuria and can be helped by low diet sodium and/or low dose thiazide diuretics. But she needs 24 hour urine testing to be sure. Hypercalciuria with crystals, and often hematuria, is well known in childhood. The white cell enzymes are, however, less common, and suggest inflammation, perhaps crystals, perhaps infection. Ask her physician if he/she thinks this is a reasonable idea, for her physician is in charge of her care. Regards, Fred Coe

  10. Michele Auc

    Dr. Coe:

    I received the below results and was wondering if you could interpret for me and offer an dietary recommendations?
    Thank You very much.

    Urine Volume- 1.75
    SS CaOX- 10.87
    Urine calcium- 338
    Urine Oxalate- 43
    Urine Citrate- 957
    SS CaP

    • Fredric L Coe

      Hi Michele, I see the prior comment was incomplete. Your SS value is high because of low volume, and also high urine calcium and oxalate. The high urine calcium can arise from idiopathic hypercalciuria or other causes, the high oxalate often from low calcium diet. Regards, Fred Coe

      • Michele Auciello

        Fred: Thank You for your comments.
        If I have high urine calcium and high oxalate…how can I decrease my oxalate if I have to increase my calcium diet.
        Does that make sense?
        Thank You,


        • Fredric L Coe

          Hi Michele, It makes sense if you add in the other crucial part: Low diet sodium. This will lower urine calcium so you can eat calcium foods with meals apt to contain oxalate. That is the essential part of the kidney stone diet. Regards, Fred Coe

        • Suzanne

          Hi Dr Coe,
          I received the following results from my 24 hour urine test and was told I was a “stone former” ??. Can you take a look and perhaps help me understand what if any changes to my diet may help.
          Calcium 339 mg
          Oxalate 46 mg
          Uric Acid 617 mg
          Citrate 544 mg
          pH 6.8
          Total urine vol 1.62L
          Sodium 131 mEq
          Sulfate 19 mmol
          Phosphorus 744 mg
          Magnesium 148 mg
          Ammonium 26 mEq
          Potassium 69 mEq
          Creatine 1131 mg
          Calcium Oxalate 3.71
          Brushite 5.85
          Sodium Urate 2.54
          Uric Acid 0.30

          Thank you for your time

          • Fredric L Coe, MD

            Hi Suzanne, Of course I do not know your clinical situation, not even the stone analysis, so my remarks are purely technical. Your urine volume is too low – needed is overl 2 liters/d, urine calcium is quite high, oxalate as well, and pH. People with urine like yours often form calcium phosphate stones – brushite or hydroxyapatite. Feel free to mention what I say to your physician, but it is your physician who is totally responsible for your care and who needs to decide what to do for stone prevention. Regards, Fred Coe


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