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Does Milk Cause Kidney Stones?

Most kidney stones are made of calcium. So, a logical next question is “does milk cause kidney stones”?

Our bodies are a complicated place. What goes in isn’t necessarily exactly what comes out. Let’s dive into everything milk and kidney stones!

What Are Kidney Stones?

Kidney stones are hard crystallizations. They form in your urine when it is too saturated with stone making molecules. The most common molecules that make kidney stones are calcium and oxalate. About 80% of kidney stones are calcium oxalate. (1)

Other common types of kidney stones are uric acid and calcium phosphate.

Does Milk Cause Kidney Stones?

Milk is notoriously a good source of calcium. Since most kidney stones are made out of calcium, does milk cause kidney stones?

No! Milk does not cause kidney stones. In fact, milk can help prevent kidney stones.

Milk is a great source of calcium. Eating enough calcium can reduce the risk of kidney stones by up to 50%. (2) Study after study finds that people who eat enough calcium have fewer kidney stones. (3) This might seem counterintuitive. Here is how this works.

Calcium and oxalate love to bind. This is how they make kidney stones! But, if you eat enough calcium, the calcium will bind with oxalate in your intestine. This will block a lot of the oxalate in the food you eat from getting absorbed. Instead, that oxalate is excreted in your feces.

When you do not eat enough calcium, more oxalate is absorbed and is excreted in urine. Higher urine oxalate can contribute to kidney stones.

Image of cartoon human showing that when you have a high oxalate meal without calcium, oxalate is absorbed in intestines, there is not enough calcium to keep bones strong and there is a higher amount of oxalate in urine and higher risk of kidney stones. Comparatively, when a high oxalate meal is consumed with dairy, you have enough calcium to protect bones, calcium binds with oxalate in intestines and oxalate is not absorbed and is instead excreted in feces. This causes a lower risk of kidney stones and weak bones.

Milk, Kidney Stones & Bone Health

Bone health is another reason it is important for people with calcium kidney stones to eat enough calcium.

People who have calcium kidney stones tend to have a lower bone mineral density and have a higher risk of osteoporosis. (4) High urine calcium is one of the most common causes of calcium kidney stones and can be a sign your body is breaking down bone. This is likely the link between osteoporosis and kidney stones.

Getting enough calcium is important to help prevent osteoporosis. (5) Nutrition for kidney stones and osteoporosis go hand-in-hand!

What Kind of Milk for Kidney Stones?

For most people, I recommend cow’s milk for kidney stones. Milk and other dairy like yogurt and cheese is one of the few foods that is naturally high in calcium.

For people who can’t tolerate or choose to avoid dairy, milk substitutes can be an option. However, remember all milk substitutes are supplemented with calcium. They they are not naturally good sources of calcium. Calcium supplements may increase risk of kidney stones. (6) No studies have looked into the risk of calcium supplemented products and risk of kidney stones.

Some vegetables are high in calcium as well. Spinach, kale, broccoli and other greens tend to be higher in calcium. However, the calcium in vegetables is not as available as calcium from dairy. They also tends to have much less calcium per serving compared to dairy. Calcium is so important for oxalate kidney stones, I usually tell my students to focus on dairy or dairy substitutes.

Bar graph showing the amount of calcium (mg) in kale (160mg) and milk (300mg) per serving

How Much Milk Do You Need For Kidney Stones?

The American Urological Association recommends that people with calcium kidney stones and high urine calcium consume 1,000-1,200mg of calcium per day from food. (7) The Dietary Guidelines for Americans also recommend 1,000-1,200mg calcium per day for general health. (8)

Eating three servings of dairy per day is good way to make sure you are getting enough calcium. A serving is:

  • One cup (8 fluid ounces) of milk
  • 3/4 cup yogurt
  • 1 ounce cheese

Learn more about the best sources of calcium for kidney stones.

Calcium Supplements & Kidney Stones

Although calcium rich foods are very good at preventing oxalate kidney stones, calcium supplements are not.

One of the most common urine risk factors for kidney stones is high urine calcium. The more calcium in your urine, the more likely you are to make kidney stones. Calcium supplements increase urine calcium MUCH more than natural sources of calcium, like milk. In fact, calcium supplements are associated with higher kidney stone risk. (6)

Calcium supplements can be a good option to help reduce oxalate absorption and reduce risk of kidney stones for some people. Most notable, people who have kidney stones as a result of bariatric surgery or bowel disease. But, for most people, calcium supplements are not ideal. Nutrition for kidney stones must be personalized to your 24-hour urine risk factors.

What Else Causes Kidney Stones?

Nutrition for kidney stones is much more than milk! Many other things can contribute to kidney stones. Some of the most common nutrition causes of kidney stones are:

  • Too much salt
  • Too much added sugar
  • Not enough water
  • Too much non-dairy animal protein
  • Not enough fruits and vegetables

Learn more about nutrition for calcium oxalate or uric acid kidney stones.

A kidney stone diet is different for everyone! To know what you can do to prevent kidney stones, you must have a 24-hour urine test to know what caused your kidney stones. Without that test, you could be focusing on entirely the wrong things!

I help people prevent kidney stones with a personalized, science-based (and delicious!) approach in Kidney Stone Nutrition School!

Happy Eating!


14 thoughts on “Does Milk Cause Kidney Stones?”

  1. Since having a calcium oxalate kidney stone at the beginning of 2022 by bone density has taken a nosedive based on the results of my most recent 5 year dxa scan at the end of 2023. The T score shows that I am now seriously on the edge of osteoporosis. I have had milk/yogurt with every meal for the past two years in place of previous calcium supplements (which my PCP upped to 1,800mg per day just two months before the kidney stone event). I, of course, am consulting with my PCP and kidney urologist but perhaps the recommended amounts in this post are for a specific age cohort. Does the amount of natural calcium required go up as we age into our 60’s/70’s? Does increasing the amount dairy from milk products help or is there a “saturation” level where more is not good? For example, the baseline of 1,000-1,200 mg calcium per day is not working. How high can I go while working to maintain a balance diet?

    1. Melanie Betz MS, RD, CSR, FAND

      Hi Karen! Great question. You certainly aren’t alone. Calcium stones and osteoporosis unfortunately often go hand-in-hand. The calcium recommendation goes up from 1000 to 1200mg at the age of 50 years. There are many other things that contribute to bone health – I’d have to know more about you to give specifics.

  2. Stephanie Sauder-Andrade

    Hi Melanie
    Thanks for all your blogs and information. You are a life saver! I do have a question about calcium supplements. I take Citracal Calcium Citrate with Vit D. The bottle says this type of calcium is highly soluble easily absorbed. Would this type of calcium supplement be appropriate or is getting calcium from food better than this type of supplement? Also, do you recommend taking Vitamin K2 for aid in calcium absorption? Thanks

    1. Betz MS, RD, CSR, FAND

      Hello! Thank you so much! If you have high urine calcium, I’d HIGHLY advise against any form of calcium supplement. It is far better to get that calcium from food. This article touches on this a bit more.
      I don’t routinely recommend vitamin K2.
      Hope that helps!

  3. Marino Richard

    Your very helpful and as always informative, keep the 411 coming to us, P.S. like the recent picture of you promoting the whole lemon in hand.

  4. So if I take a Multi-Vitamin that has 100% of my calcium, do I still need to eat lots of diary products and other foods with calcium?
    Can I get too much calcium?

  5. Yea! I can start drinking milk with dinner every night. As a woman, I was worried if I was getting enough calcium in my diet since I cut back on calcium. So glad I signed up for your newsletters – very helpful in decision making!

  6. I have to watch my “fat” content in foods. My cholesterol runs high and my MD wants me to watch my carbs and fats. What do you think about fat free milk. I am willing to start drinking milk as you suggest, but I have to watch fat in dairy type products, yogurt included. Thanks!

    1. Melanie Betz MS, RD, CSR, CSG

      I have no problem with fat free or low fat dairy one bit! I will say, that the saturated fat in dairy actually isn’t associated with the same harmful heart health issues and high cholesterol as saturated fat from meat is! Something to ask your dietitian about!

  7. Bonnie Mohrhusen

    I have had many urine tests for UTI’s. Do they qualify as a 24 hour urine test? The urology department at my local hospital has given me a sheet of dietary guidelines and are monitoring my kidney stone via future CAT scans, but I’ve not been told what type of kidney stone I have.

    Your guidelines do concur with the guidelines given me by the hospital doctor who does nothing but kidney stones.

    1. Melanie Betz MS, RD, CSR, CSG

      Hi Bonnie! My guess is those UTI urine tests were just spot urine tests? (aka pee in a cup – not collecting your urine over an entire 24 hour time period?) You can learn more about that 24-hour urine test here.
      Unfortunately, most urologists are very good at getting rid of stones- but very few urology fellowship programs dive deep into actual stone prevention. I’d suggest sharing my site and credentials with your doctor and ask them what they think!

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