How can I prevent kidney stones?

June 12, 2015 Lisa Cantkier


It’s estimated that 1 in 10 people will have a kidney stone in their lifetime. I had kidney stone surgery (percutaneous nephrolithotomy) about a year ago to remove 3 calcium oxalate stones that were causing me terrible agony—if you’ve had stones before (hopefully you haven’t and never will) you’ll know what I mean! I hadn’t been able to find out the cause of the stones from doctors and was instead informed of risk factors, such as celiac disease in general and calcium supplementation. I took the calcium supplementation for about 9 years under the advice of my naturopath at that time due to bone mineral density (BMD) loss (also linked to celiac disease unfortunately) which is another story!

So here I was a year ago in a catch 22—needing to stop calcium supplementation to reduce the risk of forming stones, yet aware that I needed that calcium to prevent/increase my BMD. My urologist (urologists specialize in problems of the urinary tract) recommended that I see a kidney stone dietician and a nephrologist (nephrologists specialize in kidney care and treating diseases of the kidneys).

I was surprised to find out that the kidney stone dietician and nephrologist work out of the St. Michael’s Hospital (Toronto) Regional Stone Program, which is the only stone prevention clinic in Canada, providing a unique focus to the treatment of renal stones in its primary prevention initiative. Prevention of stones (and bone loss)—I need you! So here is what I was taught at a recent appointment and follow-up appointment today…

The following list includes some of the recommendations I received from my kidney stone dietician and nephrologist based on my specific needs. I am sharing this strictly for the purpose of sharing information, as I found these recommendations interesting; the following information is not intended to be advice for anyone. Always speak to your health professional before making any changes to your diet.

*If you’d like a complete list of “YES” foods (low in oxalates), please send me a message by clicking here.


Recent scientific research shows that dairy actually helps prevent kidney stones. The calcium and magnesium in dairy binds to oxalate. Oxalate is a naturally occurring molecule found in abundance in plants and humans. Oxalate is not a required nutrient and too much can lead to kidney stones. Dairy decreases our ability to absorb oxalate and form stones. Those who consume dairy have a 40% lower risk of forming stones. I was advised to consume at least 3 cups of calcium-rich dairy per day (that could include *kefir from cow/goat milk, yogurt, cow/goat milk, cottage cheese and other cheeses). I found this interesting as many people I know who are stone formers have told me they eliminated all dairy from their diet, fearing the calcium intake will increase their risk of stones. Apparently, the opposite is true. *Although I can’t imagine consuming 3 cups of it, I like the research on kefir as it’s easier to digest and lower in lactose than plain cow’s milk. It’s also high in probiotics, vitamin K (linked to better calcium absorption) and other vitamins and minerals. Dairy has been recommended to me to both help increase my intake of calcium and help prevent kidney stones.

Drink 2-5 liters (5, are you kidding?!) of water per day with 1/4 cup of pure lemon juice; I drink organic lemon juice only as other kinds contain nitrites. Alternatively, I was advised to add 1 oz (or 2 tablespoons) of lemon juice to half a liter of water. The lemon juice contains citrate, which binds with calcium and prevents calcium from binding with oxalates which in turn can form stones. This is challenging, however, the nephrologist said that studies show those who drink the highest quantities of water exhibit the lowest amount of stone formation. There is a lot of research backing up the effectiveness of lemon juice in stone prevention. At my appointment today it was touted as one of the best and most effective ways to prevent stones.


• Keep away from high oxalate foods as they can lead to high oxalate in urine, increasing risk of calcium oxalate stones. including (those in bold are considered very high): almonds, almond milk, avocado, baked potato with skin, bamboo shoots, beets, canned pineapple, cashews, cooked celery, collards, dates, dried figs, dried pineapple, dried prunes, French fries, grapefruit, kiwi, mashed potatoes, okra, olives, orange, parsnip, peanuts, pecans, pistachios, potato chips, potato salad, pumpkin seeds, raspberries, raw carrots, rhubarb, rutabaga, spinach (raw and cooked), sunflower seeds, sweet potatoes, tangerine, tomato sauce, turnip, walnuts, yams. Oh dear, what a long list

Keep all forms of salt intake to a minimum. Stones thrive in a salty environment, including table salt, sea salt, Himalayan rock salt. Aim to consume under 2000 mg of sodium per day. Stone formers need to cut out processed and fast food as it is crazy high in sodium.

Eat less animal protein (animal flesh, poultry, organ meat, fish). Too much animal protein leads to high levels of uric acid and sodium, low levels of citrate and an acidic urine pH. Try to consume portions the size of the palm of your hand and thickness of little finger. Vegetarians have half the rate of forming stones. Interesting!


Avoid vitamin C supplements as they get metabolized into a form of oxalate.

Maintain a healthy weight as weight is linked to stone formation.

Are you a stone former and what do you do to prevent stone formation? ♦

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