People who have kidney stones, particularly calcium oxalate stones, are required to follow a low-oxalate diet,
which prohibits foods such as beets, chocolate, spinach, rhubarb, tea, and almonds.
This diet is especially important for people who have calcium oxalate stones.
Since spinach contains a high concentration of oxalates, eating it may increase one's risk of developing calcium oxalate stones.
Spinach should be avoided by people who have these stones or who have a significant risk of developing them because of this reason.
People who have had kidney stones in the past may be given the recommendation to reduce the amount of oxalate-rich foods they consume.