Understanding Kidney Stones, Calcium & Oxalate

If you have suffered from kidney stones, you may have encountered somebody who told you to cut down on your calcium intake.

What does calcium have to do with kidney stones? Why would well-meaning, but ill-informed friends tell you to cut it out?

And what are the proper steps to take instead?

I am going to answer all these questions for you – and more. We are going to examine the kidney stone/calcium connection and see how to avoid the painful problem.

The Most Common Kidney Stone

If you have a kidney stone, there is a good chance that it is a calcium oxalate stone. (Here is where some of those ideas about consuming less calcium come in… I will debunk that soon.)

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Calcium oxalate stones from like this:

You have too much stone-forming substances (in this case oxalate) and not enough liquid in your urine. The stone-forming substances start sticking together instead of flushing out when you go to the bathroom. Oxalate crystalizes in the urine, and then it essentially sticks on to the calcium your kidneys brought to your urine.

Once binded together, you have a calcium oxalate stone.

So Should You Quit Calcium?

When I tell you that most kidney stones are formed by calcium, your next logical thought will probably be to cut down on calcium in your diet.

Except, that is not the case at all.

Calcium is necessary for your body. If you are depleted of calcium, you will have a long, long list of extra health issues outside of kidney stones – plus, you may actually get more kidney stones.

It sounds counterintuitive, but look at the findings of this study:

Men with hypercalciuria (too much calcium in their urine) were instructed to either follow a diet of low calcium (400 mg) or of high calcium (1200 mg). After 5 years, the high calcium group had slightly less than half the kidney stone recurrence than the low calcium group.

The reason for this is calcium can actually inhibit the absorption of oxalate, the second part of a calcium oxalate stone. 

Keep Reading: 6 Easy Ways to Get Rid of a Kidney Stone Fast 

Bonus: Download This Essential Home Remedies Guide  that will show you how to tackle your worst kidney stone symptoms quickly.

Honing In On Oxalate

Oxalate is a natural substance you get through many different healthy foods you eat. Outside of kidney stone creation, it is good for you.

But the trouble here is that it binds with calcium.

  • When things are working properly, that binded calcium oxalate should be easily excreted from the body
  • When things are not working probably, that binded calcium oxalate forms into kidney stones

When it comes to preventing those common calcium oxalate stones, it is the oxalate part that you should be focused on limiting, not the calcium.

RELATED: Will The Keto Diet Cause Kidney Stones? 

So What Should You Eat? 

Though we now understand that we need plenty of calcium, that does not mean all calcium sources are equal – especially for kidney stone sufferers.

The type of calcium you should focus on is dietary calcium, the calcium you get from the food you eat.

Unless a doctor or naturopath is monitoring your, a calcium supplement can potentially cause you more kidney stone problems.

If you want to learn more about why calcium supplements are not always the best choice for improving your body’s calcium levels, check out this 5-minute video by Dr. B.J. Hardick:

Outside of avoiding calcium supplements, we also know that you should be limiting foods that are high in oxalate. These include:

  • Spinach
  • Swiss Chard
  • Almonds (and nuts in general)
  • Sesame Seeds
  • Soy Products (milk, cheese, yogurt)
  • Sweet Potatoes
  • Okra
  • Beets
  • Chocolate
  • Black Tea

So if you want to get plenty of calcium while reducing your oxalate intake, here are some pointers I follow:

  • Dairy sources of calcium are low in oxalate, so those are safe choices
  • Since you will be limiting many leafy greens, which are high in oxalate, try adding in some cabbage; it is low in oxalate, but one cup has about the same amount of calcium as spinach
  • Cauliflower, cucumber, peas, and radishes are all examples of low oxalate veggies with a good amount of calcium
  • Avocado is low in oxalate and can help supplement fat content you may be losing by limiting nuts; 1 avocado also has about 24 mg of calcium
  • Sardines are one of the very best sources of calcium in all of our food sources, and they only have 4.8 mg of oxalate

At the end of the day, you will never (and should never) cut out all the oxalate from your diet. The goal is to reduce it and make sure you are eating enough calcium to inhibit an overgrowth of oxalate.

Just remember: if you know you are going to have oxalate-rich foods, eat plenty of calcium-rich foods in the same meal.

RELATED: Why Kidney Stones Are So Painful and How To Treat and Prevent Them 

Other Ways To Prevent Calcium Oxalate Stones

Avoiding oxalate and getting the right amount of calcium are not the only steps you can take to prevent a calcium oxalate stone. I want to leave you with five extra tips ward them off:

  • Drink plenty of water: Without a doubt, one of the #1 things you can do to reduce your chances of kidney stones of any kind is to get plenty of fluids. You do not want concentrated urine filled with stone-forming substances. You want to flush all of that out as frequently as you can.
  • Reduce sodium: When you reduce the amount of sodium in your diet, you also limit excess calcium in your urine. You should not be having any more than 2 grams each day.
  • Limit animal protein: Animal protein is directly connected with kidney stone formation. Researchers recommend no more than 80 grams per day. You can supplement with other forms of protein like quinoa.
  • Maintain a healthy weight: Not only is obesity correlated with kidney stones, so is diabetes. Losing weight and taking steps to improve your diabetes are both ways to fight kidney stones.
  • Do not overdo the vitamin C: Vitamin C can turn into oxalate in your urine – so if you have a kidney stone issue, you may want to be careful with supplementing vitamin C.

If you do end up with a stone, you can try taking Chanca Piedra. This natural herb is translated “stone breaker.” It can help break up the calcium oxalate stone, so it passes more quickly and easily.

Read Next: Fighting Kidney Stones with Chanca Piedra Tea

Sources:

https://www.kidney.org/atoz/content/calcium-oxalate-stone
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1455427/
http://www.northwoodsurology.com/sites/default/files/docs/Low-oxalate-diet.pdf