Kidney stones affect approximately 12% of the American population, and calcium oxalate stones account for almost 90% of kidney stone incidence. Oxalates are organic chemicals found in certain foods (such as spinach and beets) that may combine with calcium to form calcium oxalate, an insoluble chemical the human body cannot use.
Since 20-40% of recurrent kidney stones have been associated with elevated urinary calcium, it was originally thought that consumption of high amounts of calcium might cause or contribute to stone formation. However, recent research has shown that calcium restriction may actually increase the risk of kidney stones under certain conditions.
Many studies have investigated the role of nutrition in helping to reduce kidney stones. In general, the intake of calcium through food and/or supplements does not contribute to an increased incidence of kidney stones. In fact, with very few exceptions, getting adequate dietary calcium actually reduces your risk for kidney stones.
If you currently suffer from kidney stones, we recommend consulting with a physician to determine the best course of action for your specific situation.
Note: it is best to take calcium supplements with meals (rather than between meals) to most effectively inhibit oxalate absorption.
Whole foods are the best source of calcium?
Humans have built strong bones without calcium supplements since the dawn of of humanity. After all, real food is the best source of both calcium and calcium cofactors!
Grassfed dairy products – dairy is ubiquitously applauded as the be-all-end-all source of calcium, but we need to look at the bigger picture.
First, dairy from factory-farmed cows has virtually negligible levels of K2 and other fat-soluble vitamins. Second, the pasteurization and homogenenization makes it very difficult to digest. Finally, dairy is not tolerated well my many people. If it causes an inflammatory response, it’s not going to support healthy bones.
If you tolerate dairy, it can be an excellent source of calcium and k2. Seek out aged cheeses, grassfed ghee, grassfed butter, and raw milk for the most nutrients.
Leafy greens – Kale, bok choy, spinach and collard greens are good sources of calcium. Remember to serve them with a source of k2, such as pastured eggs, melted butter or ghee.
Blackstrap molasses – If you use sweeteners in your daily coffee, a great substitute would be switching sugar for molasses. A tablespoon of blackstrap molasses contains 8% of the daily value of calcium.
Canned seafood – Canned sardines and canned salmon contain the fish bones, an excellent source of calcium. If you haven’t eaten these options before, don’t let that turn you off – the bones are barely noticeable as texture.
Black eyed peas and white beans – Although legumes can be difficult to digest for some people, they can be a good source of calcium. I highly recommend properly preparing them by soaking them to reduce the anti-nutrients.
Homemade bone broth… is it a source of calcium? Here’s a surprise: Bone broth, homemade or otherwise, is not a good source of calcium according to this research by author and traditional food advocate Kaayla Daniel! However, it is important for building healthy bones. According to Kaayla, “Bone is built on a scaffold of collagen, making collagen the most important bone building component in broth.”
In conclusion… the best ways to get adequate calcium and ensure you are absorbing it includes:
Think twice about calcium supplements, which lack cofactors required for calcium utilization
Focus on real food sources of calcium, such as leafy greens and raw dairy products.
Enjoy foods and food-based supplements rich in calcium co-factors, such as grassfed dairy and cod liver oil
Increase your magnesium intake with foods and specific supplements
Support healthy fat digestion so you are able to absorb fat-soluble vitamins.