Oxalate is a naturally occurring molecule found in abundance in plants and humans. It’s not a required nutrient for people, and too much can lead to kidney stones.In plants, oxalate helps to get rid of extra calcium by binding with the oxalate. That is why so many high-oxalate foods are from plants.owever, when too much oxalate continues through to the kidneys, this can lead to kidney stones. Calcium oxalate kidney stones are the most common type of kidney stone in the United States. The higher the levels of oxalate, the greater risk there is of developing these kinds of kidney stones.