Oxalate is found throughout nature; it’s produced in most edible plants and fruit, but also in humans as part of normal liver metabolism. Oxalate has no known benefit to our bodies – it’s either filtered by the kidneys and excreted through the urinary tract, metabolized by our gut bacteria, or removed from the body through the stool.
Many people choose to limit the amount of oxalate in their bodies to keep their kidneys healthy. Avoiding or reducing oxalates found in food – known as exogenous oxalate – is commonly done because limiting endogenous oxalate – the oxalate produced in the body – can be a bit more difficult.
Discover the differences between common oxalate sources – endogenous and exogenous oxalates – and simple steps you can take to reduce urinary oxalate. Your kidneys will thank you!
Endogenous oxalate: Circulating Oxalate
The human body is a highly-complex machine. At any given moment, your body is breaking down chemicals and turning them into nutrient-rich compounds that keep your bones strong, heart pumping, and brain sharp.
Oxalate, an anti-nutrient, can be produced endogenously as part of these chemical breakdowns, and production can be increased due to several factors, including an enzyme imbalance because of genetic variation and differences in lifestyle with varying intake of vitamin B6, magnesium, or thiamine. Increases in oxalate generation can also be a consequence of high doses of vitamin C or consumption of high levels of fructose.
Healthcare professionals can help some individuals limit endogenous oxalate production by recommending certain vitamins, including Vitamin B6, which helps support healthy metabolic activity.
Exogenous oxalate: Oxalate in the wild
Oxalate is the chemical outcome of metabolism in plants, including spinach, potatoes, beets, and dozens of other fruits and vegetables.
Exogenous, or dietary, oxalate is the second oxalate source. Exogenous oxalate (2-50%) may be absorbed from the gastrointestinal tract the bloodstream, which is filtered by the kidneys and then expelled through the urinary tract. Oxalate is considered an anti-nutrient in the GI tract because it keeps important elements, such as calcium, magnesium, and iron, from being readily absorbed. Too much oxalate from either source (endogenous or exogenous) can make it more difficult for your kidneys to filter.
There are a handful of ways to reduce the amount of diet-derived oxalate prior to absorption. Limiting foods with a lot of oxalate is where many people start, but a low-oxalate diet can be difficult to maintain. Adding calcium to your diet can also help reduce the absorption of oxalate from the GI tract into your bloodstream, assisting in the maintenance of your kidney health and overall nutrition.