Oxalic acid, or oxalate, is a compound in many plant foods. In large quantities, it can inhibit the absorption of some nutrients. Learn more.

Oxalic acid is a natural substance found in many plants, including leafy greens, fruits, vegetables, nuts, seeds, and cocoa . Rhubarb contains approximately 570–1,900 mg of oxalate per 3.5 ...

Since a lethal dose of oxalic acid is somewhere between 15 and 30 grams, you’d have to eat several pounds of rhubarb leaves at a sitting to reach a toxic oxalic acid level, which is a lot more ...