What Not to Eat If You Have Oxalate Kidney Stones: A Detailed Dietary Guide

December 25, 2025 •

4 min read

Up to 1 in 10 people will develop a kidney stone in their lifetime, with calcium oxalate being the most common type. If you have oxalate kidney stones, adjusting your diet is a critical step in preventing future episodes.

Quick Summary

This guide details which high-oxalate foods to limit or avoid when managing calcium oxalate kidney stones. It covers important dietary factors like proper calcium intake, staying hydrated, and reducing salt and animal protein to lower your risk.

Key Points

Restrict High-Oxalate Foods: Limit or avoid foods such as spinach, rhubarb, beets, nuts, and chocolate to lower urinary oxalate levels.
Increase Dietary Calcium: Do not restrict calcium from food sources; instead, ensure adequate intake (1000-1200 mg/day) to bind oxalate in the gut and prevent its absorption.
Stay Well-Hydrated: Drink plenty of water throughout the day (around 2-3 liters) to dilute urine and make it harder for crystals to form.
Moderate Sodium Intake: Reduce your consumption of high-sodium processed foods, fast food, and canned items, as high salt increases urinary calcium.
Limit Excess Animal Protein: Moderate your intake of animal protein like meat, fish, and eggs to decrease urinary calcium, oxalate, and uric acid.
Avoid High-Dose Vitamin C Supplements: Unless medically necessary, avoid high-dose vitamin C supplements (over 500 mg/day), as the body can convert it to oxalate.
Choose Low-Oxalate Foods: Opt for lower-oxalate alternatives like cauliflower, cabbage, white rice, bananas, and certain nuts to build your diet around.

Understanding Oxalate's Role in Kidney Stones

Kidney stones, particularly calcium oxalate stones, form when minerals and salts in your urine become highly concentrated and crystallize. Oxalate is a naturally occurring compound found in many plant-based foods. For most healthy individuals, oxalate is harmless. However, for those with a history of calcium oxalate stones, controlling dietary intake is essential. When calcium and oxalate are present in the kidneys in high amounts, they can bind together to form hard mineral deposits. The good news is that by making some intentional dietary adjustments, you can significantly reduce your risk of developing more stones.

High-Oxalate Foods to Limit or Avoid

A key component of managing oxalate kidney stones is being mindful of which foods are highest in this compound. You do not necessarily have to eliminate all oxalate from your diet, but moderation and careful pairing with calcium are important strategies.

Vegetables and Fruits

Certain plant-based foods, even those often considered healthy, contain high levels of oxalate. It's crucial to identify these items so you can moderate your consumption:

Spinach and Rhubarb: These are two of the highest-oxalate foods available and should be heavily restricted or avoided.
Beets and Beet Greens: Both the root and the greens contain high oxalate levels.
Sweet Potatoes: Considered a high-oxalate vegetable.
Okra: This vegetable has a high oxalate content.
Berries: Certain berries, like raspberries and blackberries, are higher in oxalates than other fruits.

Nuts, Seeds, and Legumes

Many popular nuts, seeds, and legumes are known to be high in oxalates.

Nuts: Almonds, cashews, and peanuts (a legume) are particularly high in oxalates. Lower-oxalate options include walnuts, pecans, and macadamia nuts.
Seeds: Sesame seeds and chia seeds contain significant oxalates.
Legumes: In addition to peanuts, some other beans can be higher in oxalates, including navy and kidney beans.

Beverages and Sweets

Your beverage choices and sweet treats can also impact your risk of stone formation.

Chocolate and Cocoa: These contain moderate to high levels of oxalate, especially dark chocolate.
Black Tea: A major source of oxalate for some individuals.
High-Sugar Drinks: Colas and fruit juices with added sugar can increase stone risk.

Beyond Oxalate: Other Dietary Factors

While oxalates are a primary concern, other dietary habits play a crucial role in preventing kidney stones.

The Problem with Sodium

High sodium intake can increase the amount of calcium in your urine, which then makes it easier for stones to form. To reduce your risk, focus on a low-sodium diet and avoid processed foods, fast food, and excessive condiments.

Limiting Animal Protein

Excessive animal protein from sources like red meat, poultry, fish, and eggs can increase your risk of forming both calcium oxalate and uric acid stones. It's recommended to moderate your intake, often limiting it to no more than 6-8 ounces per day, and incorporate plant-based proteins instead.

The Right Amount of Calcium

Contrary to popular belief, restricting calcium can actually increase your risk of stones. When you consume enough dietary calcium, it binds with oxalate in your intestines before it can be absorbed and reach your kidneys. Aim for 1000-1200 mg of calcium daily from food sources like milk, yogurt, and low-oxalate greens, and pair calcium-rich foods with higher-oxalate foods when you do consume them. Consult with your doctor before taking calcium supplements, as they may increase stone risk for some individuals.

High vs. Low Oxalate Food Choices


Category	High Oxalate (Limit)	Low Oxalate (Enjoy)
Vegetables	Spinach, Rhubarb, Beets, Sweet Potatoes, Okra	Cauliflower, Cabbage, Mushrooms, Onions, White Potatoes
Nuts & Seeds	Almonds, Cashews, Peanuts, Sesame Seeds, Chia Seeds	Walnuts, Pecans, Flax Seeds, Hemp Seeds
Grains	Wheat Bran, Buckwheat, Brown Rice, Grits	White Rice, Cornmeal, White Bread, Oat Bran
Beverages	Black Tea, Chocolate Milk, Colas, Grapefruit Juice	Water, Lemonade, Herbal Tea, Coffee (moderate)

The Power of Hydration

Proper hydration is the most important step in preventing kidney stones. Drinking plenty of fluids, primarily water, dilutes the minerals in your urine, making it more difficult for crystals to clump together and form stones. A meta-analysis published by the National Kidney Foundation found that producing 2 to 2.5 liters of urine per day significantly reduces kidney stone risk. You should aim to drink enough to keep your urine light-colored or clear throughout the day.

Conclusion: Making Informed Choices

Managing oxalate kidney stones is about making smart, informed dietary decisions rather than completely eliminating food groups. By focusing on limiting high-oxalate foods, reducing excess sodium and animal protein, ensuring adequate dietary calcium, and staying well-hydrated, you can take control of your kidney health. Always consult with a healthcare professional or a dietitian specializing in renal health for a personalized plan, as your specific needs may differ. Taking proactive steps today can help prevent the pain and discomfort of future kidney stones.

For more dietary guidance, consider reviewing information from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Eating, Diet, & Nutrition for Kidney Stones.

Frequently Asked Questions

The highest-oxalate foods, which should be heavily limited or avoided, include spinach, rhubarb, almonds, cashews, beets, and dark chocolate.

It is best to strictly limit or avoid spinach due to its extremely high oxalate content. If you do eat it, pair it with a calcium-rich food like cheese to help bind the oxalate in your gut.

No, dietary calcium from milk and other foods does not cause stones. In fact, it helps prevent stones by binding with oxalate in the intestines. It is calcium supplements, especially when not taken with food, that can increase risk.

Water is the most important fluid for preventing kidney stones. Aim to drink 2-3 liters per day to keep your urine diluted. Adding lemon juice to water can also be beneficial.

High sodium intake, common in processed and fast foods, increases the amount of calcium excreted in the urine. This rise in urinary calcium can increase the likelihood of stones forming.

Not necessarily. While high-oxalate nuts like almonds and cashews should be limited, you can enjoy lower-oxalate nuts in moderation, such as walnuts, pecans, and macadamia nuts.

High-dose vitamin C supplements (typically over 500 mg) can increase the body's production of oxalate. It's generally advised to avoid them and get vitamin C from food sources instead.

It is better to get your calcium from dietary sources. The calcium in food binds with oxalate in the gut, reducing absorption. Calcium supplements, especially high-dose ones, are more likely to increase stone risk.