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Oxalates Guide: What Are They, Why Should I Care?
September 3, 2020
Photo by Jacqueline Howell from Pexels

Oxalates GuideOverview

The oxalates guide is intended to provide a walkthrough of what oxalates are and why you should be aware of them.

Oxalates, also referred to as oxalic acid, are organic compounds that naturally occur in a wide variety of plants, including everything from leafy greens, legumes, nuts, and seeds, to cruciferous vegetables, blueberries, and dark chocolate. In small quantities, the body can also create oxalates by metabolizing vitamin C.

They are essentially a protective measure that plants have to defend themselves against predators. Like lectins and phytates, oxalates are considered to be antinutrients because once consumed, they tend to bind to minerals, like calcium or iron, forming oxalate compounds and causing the minerals to be non-bioavailable and therefore not useful to the body from a nutritional standpoint.

In fact, most of this chemical binding occurs in the colon, kidneys or in the urinary tract and these once-useful minerals are then eliminated in the stool or urine. 

In addition to causing reduced absorption of vital minerals, oxalates are linked to a number of other health problems. Sensitivities that have been linked to high-oxalate consumption include the following:

  • An increase in the formation of kidney stones
  • Vulvodynia or any chronic, unexplained vulvar pain syndrome
  • A carcinogenic effect on breast tissue cells
  • Autism Spectrum Disorder

Let’s take a look at the science behind each of these links, and then explore some simple behavioral changes that may benefit those who are sensitive to oxalates.

Kidney Stones

Having a diet high in oxalates has been shown to increase the oxalate levels in urine and the general scientific consensus is that higher urinary oxalate levels increase the risk of developing kidney stones, or nephrolithiasis, in susceptible individuals. This is thought to happen when oxalates combine with calcium to form crystals which then leads to the formation of kidney stones. This particularly seems to be the case for individuals who have high urinary concentration of oxalates with low-volume output of urine, known as hyperoxaluria. (1)


Vulvodynia is a chronic pain syndrome of the vulva. It is characterized by prolonged vulvar pain that interferes with everyday living and working. Sexual intercourse, tight-fitting clothing, and prolonged sitting can cause pain for many women who suffer from vulvodynia. 

The science behind whether oxalates play any role in vulvodynia is actually mixed. A study of 130 women with vulvodynia analyzed urine samples over a 24-hour period and 59 women who were determined to have hyperoxaluria were put on a low-oxalate diet and calcium citrate supplementation for three months. After this period, 14 women, or 24-percent, demonstrated an objective positive response, but only 6 of them, or 10-percent, said that they could have sexual intercourse without pain. These results led researchers to conclude that urinary oxalates may be an irritant for some with vulvodynia, but they are unlikely to be the primary cause. (2)

As it has been shown that excess oxalate can cause epithelial reactions similar to those seen in vulvodynia, a separate case study looked at a woman who had vulvodynia and exhibited periodic hyperoxaluria and high urinary pH. She was given calcium citrate supplementation to reduce urinary oxalate concentrations and within one year, she was able to resume normal work, sexual and recreational activities without pain. When the calcium citrate was removed, she experienced a return of her symptoms. These findings suggest that in some women, oxalates may play a role in their vulvodynia. (3

Breast Cancer

A study from 2015 found that normal breast epithelial cells were transformed into breast cancer tumor cells with chronic exposure to oxalates, and oxalates had a carcinogenic effect that induced tumor formation when it was injected into the mammary cells of mice. (4

Autism Spectrum Disorder

With respect to Autism Spectrum Disorder, ASD, a study conducted in 2012 found that in comparison to neurotypical children, children with ASD showed 3 times higher plasma oxalate levels and 2.5 times higher urinary oxalate concentrations. The researchers concluded that this variation may mean that hyperoxalemia and hyperoxaluria play a role in the pathogenesis of ASD. Further testing would need to be conducted to understand whether these differences are the result of impaired renal excretion, excessive oxalate absorption in the intestines, a central nervous system disturbance from oxalates crossing the blood brain barrier or a combination of any or all of these possibilities. (5)

Oxalate Guide – It All Leads Back to the Gut

Even though the science is not definitive, knowing that oxalates may play a role in these conditions, along with the potential for oxalates to cause mineral deficiencies, many individuals could benefit by considering how oxalates may be affecting them and then by taking steps to reduce their consumption of oxalates to see if it helps to mitigate or relieve any negative symptoms.  

Oxalate Guide – Low-Oxalate Diet

Many foods that are high in oxalates are actually very healthy and have been shown to positively affect cardiovascular health, causing the medical community to recommend a low-oxalate diet, a diet that restricts oxalate intake to less than 100 mg/day, only in cases where hyperoxaluria is present.

This can easily be done by restricting the intake of common foods that are very high in oxalate, including:

  • spinach
  • potatoes
  • nuts
  • seeds
  • wheat bran
  • chocolate
  • beets. (1)

Oxalate Guide – Cooking Methods

Despite the apparent health benefits of green smoothies and fresh juices, for individuals who are susceptible to conditions that may be aggravated by oxalate consumption, it may be wise to reduce the consumption of green juices as the oxalate concentration in raw leafy greens is quite high. Additionally, it has been shown that boiling spinach, potatoes and other high-oxalate foods prior to eating them significantly reduces the oxalate content in comparison to other food preparation methods, including steaming and baking. (6)

Oxalate Dumping – A Word of Caution

This oxalates guide wouldn’t be complete without addressing oxalate dumping. It’s important to remember that oxalates are a toxin that accumulates in the body, typically as salt crystals within various epithelial tissues, so when dietary oxalates are decreased, the oxalate concentration of the blood will decrease and will elicit an elimination of the accumulated toxins from the tissues. This is the general mechanism the body has for any pharmacologic, dietary, or environmental toxin, and is the primary reason why so many dietary changes result in a detox syndrome. With respect to oxalates, this detox process referred to as oxalate dumping can cause a whole host of uncomfortable symptoms and is typically seen within 3 days to 2 weeks of significantly reducing oxalate intake. The length of time it takes for the body to expel oxalates is different for each person, in my clinical experience it can take days to years depending on various factors.

Anecdotal evidence collected by dietary clinicians and offered up by countless patients that have significantly reduced their intake of oxalates or those who have transitioned to the all-meat ‘carnivore diet’ list the following as possible symptoms of oxalate dumping:

  • General cold-like symptoms: runny nose, sneezing, sore throat, mucus congestion and ear pain
  • Eye symptoms: dry, gritty eyes, runny eyes, puffy eyelids, stabbing eye pain, blurry vision and stys
  • Digestive upset, diarrhea or constipation, and painful gritty stool
  • Urinary frequency, urgency and kidney stones
  • Skin symptoms: skin eruptions, rash on the palate or throat, canker sores on lips or tongue, vulvar itching and pain
  • Joint pain often in the shoulders, hips and knees, along with trigger finger, foot pain and restless legs
  • Generalized detox symptoms: headache or pulsating headache, tinnitus, feeling vibrations, heart palpitations, sleep disturbances and anxiety

Reducing the Discomfort

Similar to other detox processes within the body, these symptoms typically last between 3-7 days but can last much longer depending on various factors. Though it is temporary, being run down, sick or out of sorts is never fun. One of the best ways to combat this detox is to take the withdrawal of oxalates slow. Keep a food diary of your typical diet and use it to calculate your baseline average daily intake of oxalates. If your end goal is to reach 100 mg/day or lower, reduce this incrementally dropping 10 mg/day every 5-7 days depending on the severity of any detox symptoms. Though it does take additional planning and work, this should allow your body to dump the accumulated oxalate more slowly, minimizing the negative symptoms and allowing your body to adjust to the dietary changes.

Along with this, oxalate dumping symptoms can be mitigated by staying hydrated, getting adequate sleep, taking epsom salt baths and utilizing supplemental support from calcium citrate (7), magnesium, vitamin B6, and oxalate-degrading probiotics. (8)

So even though the scientific jury is still out on the specific role oxalates play in various disorders and diseases, if you suffer from symptoms that suggest oxalates could be an aggravating factor, be proactive and ask for a test that can determine if you have hyperoxaluria, take steps to make some simple dietary changes and consider supplementation choices that could help reduce the concentration of oxalates in your body. Take it slow to avoid the negative symptoms that come along with oxalate dumping, and after a brief detox period, tune in to your body and symptoms and see if any of the changes yield a positive outcome!

Hopefully, this oxalates guide has been helpful. If you’ve had issues with oxalates, I’d love to hear your story. Please share in the comments.


1. Worcester E, Coe F. Clinical Practice Calcium Kidney Stones. N Engl J Med. 2010 Sep 2; 363(10):954–963.

2. Baggish M, Sze E, Johnson R. Urinary oxalate excretion and its role in vulvar pain syndrome. Am J Obstet Gynecol. 1997 Sep;177(3):507-11.

3. Solomons C, Melmed M, Heitler S. Calcium citrate for vulvar vestibulitis. A case report. J Reprod Med. 1991 Dec;36(12):879-82.

4. Castellaro A, Tonda A, Cejas H, Ferreyra H, Caputto B, Pucci O, et al. Oxalate induces breast cancer. BMC Cancer. 2015 Oct 22;15:761. 

5. Konstantynowicz J, Porowski T, Zoch-Zwierz W, Wasilewska J, Kadziela-Olech H, Kulak W, et al. A potential pathogenic role of oxalate in autism. Eur J Paediatr Neurol. 2012 Sep;16(5):485-91. 

6. Chai W, Liebman M. Effect of different cooking methods on vegetable oxalate content. J Agric Food Chem. 2005 Apr 20;53(8):3027-30.

7. The Great Plains Laboratory, Inc. Oxalates Control is a Major New Factor in Autism Therapy. [Internet]. [cited 13th October 2019]. Available from:

8. Liebman M, Al-Wahsh I. Probiotics and Other Key Determinants of Dietary Oxalate Absorption. Adv Nutr. 2011 May;2(3):254–260.


About author

Heather Cooan

Heather is a marketing executive turned functional nutrition consultant and educator. Heather advocates for informed consent, bodily autonomy, and healthcare authorship. She speaks and writes on nutrition and lifestyle design interventions for health recovery. Heather successfully recovered her health from vulvar cancer, Hashimoto's, and lichen sclerosus. She reversed estrogen dominance, insulin resistance, arteriosclerosis, and fatty liver utilizing a food-as-medicine and integrated clinical treatment approach. Heather is a certified Functional Diagnostic Nutrition® Practitioner, Nutrition Therapy Practitioner, and is earning her Oncology Nutrition Consulting Certification. Heather successfully recovered her health from vulvar cancer, Hashimoto's, and lichen sclerosus. She reversed estrogen dominance, insulin resistance, arteriosclerosis, and fatty liver utilizing a food-as-medicine and integrated clinical treatment approach. Heather is a certified Functional Diagnostic Nutrition® Practitioner and Nutrition Therapy Practitioner.

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There are 8 comments

  • Jennifer Campbell says:

    I have just discovered what has been causing a host of vague symptoms for me over the past few years. In particular, a strange numb sensation from the middle of both feet to my lower legs, which had starting feeling tight and stiff. The circulation is good, my feet didnt look bad. The doctor sent me for nerve tests and an mri of my lower back. I tried reflexology and hot soaks, which felt great but it didn’t solve it. I had heard about oxalates, i knew they are present in foods, but when i looked at the different levels i was shocked at how much was present in the cup of garden fresh spinach i was eating daily in my healthy smoothie! 10 times what should be consumed…for the past 7 years! and robbing my body of nutrients! No wonder my body was full of stiff joints, random pains, etc. I even had episodes of deep vag pain which was there and gone for no apparant reason. I was low on energy, battling depression after years at a high stress profession and felt like crap most days having to push myself to do my daily farm chores.
    I stopped eating spinach and I’m controlling my intake of high oxalates foods, slowly weaning my body, allowing my tissues to release what is stored and drinking lemon juice. I can already feel the difference in my mobility and my joints feel good. I know it will be a while for my feet to be normal but i am so happy that i will be able to do the activities i enjoy ….it had been quite depressing thinking that my retirement would be plagued by feeling so old and worn out. Now i feel i can actively participate in the solution by using nutrition to resolve a nutrient based problem. thank you for providing information about this topic.

  • Jennifer, I’m so glad you’ve pinpointed what was going on with your body. Unfortunately, I see a lot of folks who have been negatively impacted by the “healthy smoothie” trend. For those who are sensitive to plant photochemistry like oxalic acid, green smoothies can really be problematic! Wishing you well and thanks so much for sharing.

  • Christopher Dockstader M.Ed. says:

    I enjoyed the part about frequent urination and mucus/cold like symptoms. They are true for me. I really overdid oxalates two years ago and am still paying the price. Which leads me to my only request about an edit; would you consider changing “weeks” to “years” in terms of dumping symptoms? According to Sally K. Norton and others (a young chap in England, forgot his name), recovery via dumping could take a person years depending upon volume of oxalates consumed and individual susceptibility. This seems to be the case for me and it would be very distressing to feel that after only a few weeks, aches and pains didn’t go away. Testing for oxalates via doctors is not so easy as well. Thank you for your time.

  • Christopher! I’m so glad you’ve figured out that oxalates are an issue for you. Many struggle for years before they can pinpoint plant phytochemistry and oxalic acid as their source of dysfunction. It sounds like you’re well on your way to healing. Congratulations.

    I agree with you 100% that the process of removing oxalates from the body can take a surprising amount of time for some individuals. I see this in my client population. Thank you for reaching out. I think this edit request is appropriate despite the lack of published literature to support this claim. I will add my personal experience as a practitioner to the article to make sure folks who stumble upon this resource have the correct expectations on the time it can take to expel oxalates.

  • Marshall says:

    Been one year since I stopped high oxalates foods and switched to carnivore been to ER 5 times , massive sore throat, kidney stones, stomach issues , awful …. hope it ends soon

  • Yeah, removing oxalates can really put a toll on the body. I’ve had clients with all of these issues. Often times they also report that oxalates are excreted from their gums. They get sore, inflamed, and bleed. It’s interesting how each body expels them a bit differently. Hang in there! It will get better.

  • Bridget F says:

    I have been Carnivore 4 months after being keto for one year. I was diagnosed with diverticulitis in September which I suppose was a combination of stress and the extra fiber I was getting. My hair was falling out and I felt like my body was not absorbing nutrients properly. I just went to the ER with extremely high blood pressure and a headache. I was negative for Covid last week. I had a very bad sore throat and sinus junk last week. I had not eaten my chocolate foe about 3 days when the headache and bp issues started. I ate my dark chocolate last night and my bp was normal this morning. I have never had HBP. I also took calcium yesterday. I feel fine today. The last two days I was so moody and anxious I thought I was losing it. Could all of this be oxalate dumping?

  • Definitely possible. It’s hard to say for sure without looking over your labs. There are several things that can cause the symptoms you experienced. You’re in the loop on minerals and electrolytes when following keto and carnivore, right?

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