What is oxalate?
Oxalic acid is an organic compound found in many plant species that forms oxalate when it binds to minerals. It's very common for the termoxalate andoxalic acid to mean the same thing in terms of nutrition.1
What is calcium oxalate?
Calcium is a mineral found in different types of foods, such as dairy and fruits. When oxaclic acid binds with calcium, calcium oxalate forms. In most humans, calcium oxalate forms in the kidneys where oxalic acid and calcium meet.2
How does calcium oxalate affect kidneys?
Calcium oxalate is known to cause stones in kidneys (though it's unclear why it happens in some people and not others). Kidney stones caused by calcium oxalate occurs when they form crystals inside the kidney (which itself is generally caused by a lack of sufficient fluid in the kidney). More recent research suggests that while many foods do contain oxalic acid, the body also produces oxalic acid, and this is why it's medically recommended to calcium oxalate kidney stone patients to avoid or reduce ingestion of foods that contain oxalic acid.3
What should calcium oxalate kidney stone patients do?
Quick disclaimer: this is not medical advice; evaluate all statements with a qualified health professional.
More recent research suggests that while many foods do contain oxalic acid, the body also produces oxalic acid. For that reason, many medical professionals recommended that calcium oxalate kidney stone patients do two things to help reduce the risk of forming stones:4
- Avoid or reduce ingestion of foods that contain oxalic acid
- Consume more water
- 1 Noonan, S. C., & Savage, G. P. (1999). Oxalate content of foods and its effect on humans. Asia Pacific journal of clinical nutrition, 8(1), 64–74.
- 2 Heaney, R. P., & Weaver, C. M. (1989). Oxalate: effect on calcium absorbability. The American journal of clinical nutrition, 50(4), 830–832.
- 3 Worcester, E. M., & Coe, F. L. (2010). Clinical practice calcium kidney stones. The New England journal of medicine, 363(10), 954–963.
- 4 Gul, Z., & Monga, M. (2014). Medical and dietary therapy for kidney stone prevention. Korean journal of urology, 55(12), 775–779.