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Could oxalate toxicity be the cause of your symptoms?

Updated: Oct 14, 2023

The trouble with oxalates

This is an important read for anyone with kidney stones, urinary issues, chronic joint or muscle pain, unusual rashes, or even autism. Could oxalate toxicity be the underlying cause or an aggravating factor?

Oxalate is a natural substance found in many plant foods.

In humans, when plant foods are consumed, oxalates are degraded by certain bacteria in the gut or removed from the body by being bound to minerals (particularly calcium and iron) in the intestines and are excreted in stool. Oxalate can also be removed from the body via the kidneys in urine.

Issues arise when there is too much oxalate to be excreted or if our gut doesn't contain enough of the oxalate-degrading microbes.

One of the most common issues with increased oxalates in the urine (hyperoxaluria) is the formation of kidney stones. However, if the body struggles to eliminate oxalate it can accumulate as crystals anywhere in the body. Commonly it accumulates in blood, then the eyes, bones, skin, muscles, blood vessels, heart and other organs.

High oxalates have also been linked with autism and inflammatory bowel disease. It can also be an underlying issue in those with ongoing gut problems or irritable bowel syndrome.

Signs and symptoms of oxalate toxicity may include:

Signs and symptoms of oxalate toxicity
  • Pain, muscle aches & fatigue

  • Joint pain – if deposition of oxalate crystals is in synovial fluid or connective tissue.

  • Strange rashes

  • Kidney Stones

  • Chronic UTIs, interstitial cystitis or kidney infections

  • Frequently cloudy or hazy urine

  • Vulvar pain in women

  • Gastrointestinal problems or irritable bowel

  • Recurring fungal infections

  • Gum problems

  • Sore eyes / poor vision

  • Excessive histamine signs and symptoms

  • Brain fog and fatigue

Excessive intake of high oxalate foods is often the underlying cause, particularly if combined with poor gut health, fat malabsorption, and certain nutrient deficiencies.

In rare circumstances, people can be endogenous producers of oxalate due to a genetic disorder or low vitamin B6.

What tests are used to assess for high oxalate?

  • 24hr urine test showing high urinary oxalate (gold standard - particularly if adjusted for height in children)

  • Mosaic Diagnostics Organic Acids Test (O.A.T.) – also a urine test.

Please note: Urinary tests may not be 100% accurate and give false negatives for those with sulfation problems. (Low sulfate inside kidney tubules could reduce the ability of the kidneys to remove oxalate from blood and deliver it to urine. Those with autism and HIV are known to have high urinary wasting of sulfate).

What foods are very high in oxalates?

Unfortunately, many healthy foods are high in oxalates. Spinach is one of the worst offenders.

Nuts that are high in oxalates include peanuts, cashews, pine nuts, Macadamia nuts, almonds, pecans, and hazelnuts.

Oxalates can also come from moulds, mycotoxins and fungi.

High oxalate foods

What else may increase oxalate levels or aggravate oxalate toxicity?

  • Poor gut health and digestion including a leaky gut, dysbiosis, prolonged diarrhea or constipation, and poor fat digestion.

  • Antibiotics – cause dysbiosis and some are known to destroy oxalobacter formigenes, an anaerobic beneficial bacteria that eats up oxalates.

  • Low dietary calcium – binds to oxalate for excretion.

  • Vitamin C supplementation – can metabolize to oxalate. The effect may be delayed by as much as 2 weeks.

  • Fish oil supplements – if you have poor fat absorption, fish oil may cause more absorption of oxalates. (Though some functional medicine practitioners suggest fish oil can be beneficial for those with oxalate issues).

  • Vitamin D supplementation – possibly by increasing the absorption of calcium, it may lower calcium levels in the gut needed for the binding of oxalate.

  • PEG Compounds (like Glycolax or Miralax) used for constipation – with the help of gut microbes these MAY be converted into oxalate.

  • Nystatin for thrush or a fungal overgrowth – may keep the gut leaky.

  • Endogenous production due to genetics, low vitamin B6 and from high glyoxylate levels (from its precursors glycoxal, glycolate, or the amino acids hydroxyproline and glycine). So, collagen, gelatin & glycinate forms of supplements may turn to oxalate in a small number of people.

Calcium oxalate crystal in urine.
Calcium oxalate crystal in urine.

What may improve oxalate toxicity?

  • Improved gut health and a balanced microbiome (gut bacteria break down oxalates).

  • Vitamin B1 (Benfothiamine) – keeps meat from being metabolized towards oxalate & can support endogenous producers.

  • Vitamin B6 (pyridoxal-5-phosphate) – prevents the metabolism of food to oxalate and can support endogenous producers. Note: vitamin B6 deficiency can cause internal oxalate issues, but oxalates can also cause B6 deficiency.

  • Calcium citrate – can bind to oxalates in the gut for removal. They are best taken before a meal in order for it to be effective. (The other suggestion is to consume dairy with each meal if tolerated).

  • Magnesium – may bind oxalate and can be depleted by oxalate. Is commonly deficient in those with kidney stones. In citrate form it may help break down formed oxalate crystals.

  • Anti-oxidants – like vitamin E, vitamin A, alpha lipoic acid, glutathione (or precursor NAC). Oxalates cause oxidative stress and inflammation, induce histamine release and interfere with sulfate metabolism.

  • Probiotics –Lactobacillis and Bifido bacterium strains may help to degrade oxalates, however, they prefer other food. The best probiotic supplement for those with oxalate toxicity includes oxalobacter formigenes as it requires oxalate as food to survive and therefore is an excellent degrader of oxalates. Oxalobacter probiotics are available in India, but are challenging to get elsewhere.

  • Epsom salt baths – are soothing and may help to get rid of oxalates in the skin.

  • Zinc – maintains gut integrity (prevents leaky gut) and may be depleted by oxalate.

  • Arginine – replenishes nitrous oxide and helps reduce oxidative damage from oxalates.

  • Taurine - is needed to make bile acid taurocholate which limits absorption of oxalate. Consider especially if stool turns yellow.

  • Ox bile or Lipase – helps with fat absorption. Poor fat absorption can lead to excessive absorption of oxalate.

  • Anti-histamines – to counter histamine release that oxalates can cause.

What is oxalate dumping?

What to be wary of when trying a low oxalate diet.

Reducing the intake of oxalates in the diet can be beneficial and reduce symptoms, however, it needs to be done extremely slowly to avoid a “dumping” reaction. This is where the cells are moving stored oxalate out and are being damaged in the process.

Dumping of oxalates can cause a temporary worsening of symptoms and/or a yeast flare, painful bowel movements, rashes or hives, grainy stools, pain with urination, or irritability.

Detoxing too quickly using certain supplements (e.g. active B vitamins, glutathione, MSM, liver detox herbs) can also aggravate symptoms, so support from a qualified health professional is strongly recommended before starting a low oxalate diet.

Unfortunately, waves of dumping symptoms can occur for months to years!

When should a low oxalate diet be considered?

Unfortunately, everyone has their own unique set of reactions to over-exposure to oxalates, causing differing symptoms.

But, those who consume at least 1 or more high oxalate foods per day, plus have any of the following could be wise to consider oxalate toxicity:

  • Kidney stones, interstitial cystitis, and urinary issues.

  • Frequently cloudy or hazy urine.

  • Pain that comes and goes without an obvious cause or that affects different body parts on different days.

  • Gastrointestinal issues or inflammatory bowel disease

  • Autism

  • Autoimmune disease

  • Inflammation issues (-itis conditions such as tendonitis)

  • Frequent fatigue or brain fog

  • Poor recovery from injury

  • Recurring fungal infections

  • Mucus production and congestion

Like alcohol, oxalates are toxic to all humans, we just have varying thresholds of tolerance to the amount consumed. An issue with oxalates is not a matter of an allergy or sensitivity.

Oxalate toxicity can do a lot of harm to the body. It can damage not just the kidneys, but the intestines, soft tissues, and even the brain. Through its damage to the gut it may lead to certain autoimmune diseases and since oxalates can bind to T3 thyroid hormone it may even disrupt thyroid function! Trying a low oxalate diet and any of the supplements suggested may be just what is needed for your body to thrive.

cover of low oxalate recipe and ebook

If you are on a low oxalate diet or considering trying one, my Low Oxalate Living Guidebook and Recipe eBooks are ESSENTIAL resources. Check them out here...

Needing help navigating the low oxalate journey? Not sure what supplements to take and when? Want guidance and support to heal your gut and address the root causes of your health struggles?

Then see how you can work with me to get your personalized functional medicine solution (no matter where you are in the world).

functional medicine practitioner Georgina Compton

Dr Georgina Compton

Certified Functional Medicine Practitioner & Chiropractor

B.Sc, B.Chiro, CFMP, MZNCA

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Rated 5 out of 5 stars.

Can brain fog be a main symptom of high oxalates? Have hashimotos and terrible brain fog in pre and post menopause …. HRT hasn’t resolved the fog


scofio willie
scofio willie
Mar 08, 2023
Rated 5 out of 5 stars.



Can you have oxalate poisoning and issues with joints, connective tissue, vulvar pain, eye floaters, etc but NOT have kidney issues?

Replying to



Rachel H
Rachel H
Mar 09, 2022

How do you know if you have sulfate issues?


What are N.B urinary test?

Annette Price
Annette Price
Jul 17, 2021
Replying to

N.B. is short for the Latin phrase nota bene, it means “note well.” It just means to take note of what follows it. So she’s just saying to take note that urinary tests aren’t 100% accurate.

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