Oxalates are naturally occurring compounds found in some foods that bind to minerals in your body, and while they aren’t necessarily bad, high amounts of oxalates can pose problems for people with kidney disease or kidney stones. Most kidney stones are calcium oxalate stones, and they develop when excess oxalates bind with calcium in your kidneys. Vegetables that have high oxalates are spinach, potatoes, and beets.
Oxalates can also build up in your digestive system if you’re taking antibiotics. Antibiotics not only kill off pathogens but also the good bacteria that feed on oxalates. This buildup of oxalates could limit vital minerals from being absorbed by your body.
If you love spinach or other foods high in oxalates, cooking these foods can reduce these oxalates. To prevent calcium oxalate kidney stones, combine high-oxalate foods with foods rich in calcium. The calcium in your meal will bind with the oxalates and pass through your digestive system before they can reach the kidneys.