Updated: Sep 12
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?
Oxalate is a natural substance found in many plant foods. In humans, when plant foods are consumed, oxalates are 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.
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.
Signs and symptoms of oxalate toxicity can include:
Pain, muscle aches & fatigue
Joint pain – if deposition of oxalate crystals is in synovial fluid or connective tissue.
Chronic UTIs, interstitial cystitis or kidney infections
Frequently cloudy or hazy urine
Vulvar pain in women
Recurring fungal infections
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 B5.
What tests are used to assess for high oxalate?
24hr urine test showing high urinary oxalate
Great Plains Laboratory Organic Acids Test (OATS) – also a urine test.
N.B. 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 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, hazelnuts, and walnuts.
Oxalates can also come from moulds, mycotoxins and fungi.
What else can increase oxalate levels or aggravate oxalate toxicity?
Poor gut health and digestion including a leaky gut, dysbiosis, prolonged diarrhea or constipation, poor fat digestion.
Antibiotics – causes 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 metabolise to oxalate. The effect may be delayed 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 – possibly by increasing 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 low vitamin B5 (pantothenic acid)
What may improve oxalate toxicity?
Improved gut health and a balanced microbiome (gut bacteria break down oxalates).
Vitamin B1 (Benfothiamine) – keeps meat from being metabolised towards oxalate.
Vitamin B6 (pyridoxal-5-phosphate) – prevents metabolism of food to oxalate.
Vitamin B5 (Pantothenic acid) – prevents oxalate production by the body and gut microbes via glycolate cycle.
Calcium citrate – can bind to oxalates in the gut for removal. Take before a meal for it to be effective. (Or 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 oxylate 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. Having a probiotic supplement containing oxalobacter formigenes would be ideal as it requires oxalate as food to survive and therefore is an excellent degrader of oxalates. However, no such product is currently available. (One is in the pipelines though).
Epsom salt baths – 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 that helps reduce oxidative damage from oxalates.
Taurine - 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 released that oxalates can cause.
What to be wary of when trying a low oxalate diet.
Reducing intake of oxalates in the diet can be beneficial and reduce symptoms, however, it needs to be done very 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 when starting a low oxalate diet.
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
Inflammation issues (-itis conditions such as tendonitis)
Frequent fatigue or brain fog
Poor recovery from injury
Recurring fungal infections
Mucus production and congestion
Oxalate toxicity can do a lot of harm in 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 can lead to certain autoimmune diseases and since oxalates can bind to T3 it can 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.
For more information check out:
Trying Low Oxalate Facebook group by Susan Owens
For professional help please book a free discovery call to see how I can help online or in person.
Dr Georgina Compton
Certified Functional Medicine Practitioner
B.Sc, B.Chiro, CFMP, MZNCA