Oxalic Acid
Naturally occurring compound in many plant foods. Binds to calcium and may reduce mineral absorption. Highest in spinach, rhubarb, and beet greens.
No established daily requirement for this nutrient.
Top Foods Highest in Oxalic Acid
Amount per 100g serving. Values in mg per 100g.
Foods Highest in Oxalic Acid (Table)
| # | Food | Per 100g | Group |
|---|---|---|---|
| 1 | Rhubarb, raw | 400 mg | Fruits and Fruit Juices |
Health Effects of Oxalic Acid
Oxalic acid is an anti-nutrient found in many plant foods (spinach, rhubarb, beet greens, almonds) that binds minerals, particularly calcium, forming insoluble oxalate crystals.
Oxalic acid is not a nutrient; no deficiency exists. However, very low oxalate diets may be recommended for kidney stone-prone individuals.
High oxalate intake reduces calcium and iron bioavailability from those foods. In susceptible individuals, dietary oxalate contributes to calcium oxalate kidney stones, the most common kidney stone type.
Absorption & Interactions
Only 2-15% of dietary oxalate is absorbed, primarily in the colon. Calcium in the same meal binds oxalate, reducing both oxalate absorption (good for kidneys) and calcium absorption.
Frequently Asked Questions
How much Oxalic Acid do I need per day?
There is no established daily requirement for Oxalic Acid.
Which food has the most Oxalic Acid?
The food highest in Oxalic Acid is Rhubarb, raw with 400 mg per 100g.
What does Oxalic Acid do in the body?
Naturally occurring compound in many plant foods. Binds to calcium and may reduce mineral absorption. Highest in spinach, rhubarb, and beet greens.