Most vegetables are naturally low in oxalates, containing less than 25 mg per serving. The vegetables that cause problems are a relatively short list of heavy hitters like spinach, beets, and rhubarb. If you’re trying to reduce oxalate intake (the standard recommendation for kidney stone patients is under 40 to 50 mg per day), you have far more safe options than restricted ones.
What Counts as Low Oxalate
A vegetable is considered low oxalate if it contains less than 25 mg per serving. To put that in perspective, a single cup of raw spinach can contain 840 to 1,212 mg of oxalate per 100 grams of fresh weight. Beet leaves range from 722 to 1,909 mg per 100 grams, and rhubarb stalks hit roughly 987 mg per 100 grams. These are the outliers. Most of the vegetables in your grocery store fall well under the 25 mg cutoff.
Best Low-Oxalate Vegetables
Some vegetables contain so little oxalate that they’re essentially negligible. Bok choy comes in at just 1 mg per cup raw, and chopped kale has about 2 mg per cup. These are among the lowest-oxalate leafy greens available, making them practical swaps if you’re used to eating spinach-heavy salads or smoothies.
Beyond leafy greens, here are vegetables that consistently fall in the low-oxalate range:
- Cruciferous vegetables: broccoli, cauliflower, cabbage, and Brussels sprouts
- High-water vegetables: cucumbers, zucchini, and bell peppers
- Alliums: onions and garlic
- Others: mushrooms, peas (green, fresh), lettuce (iceberg and romaine), and radishes
Carrots, corn, and turnips are also generally low, though oxalate content can vary depending on growing conditions and preparation. When in doubt, sticking with cruciferous vegetables and the leafy greens listed above gives you the widest safety margin.
Vegetables to Avoid or Limit
The high-oxalate list is short but important to know. Spinach is the biggest offender by a wide margin. Beet greens and beet roots both qualify as high-oxalate foods, with root tissue alone containing 95 to 171 mg of oxalate per 100 grams. Rhubarb, Swiss chard, and sweet potatoes also rank high. Raw beet leaves can deliver nearly 2,000 mg per 100 grams in some cultivars, which is enough to blow through several days’ worth of recommended limits in a single serving.
Legumes are worth mentioning here because they’re often grouped with vegetables in meal planning. Oxalate levels vary dramatically across legumes, ranging from 4 to 80 mg per 100 grams of cooked weight depending on the type. Lentils and peas tend to sit at the higher end (168 to 294 mg per 100 grams in some analyses), while common beans are more moderate at 99 to 117 mg per 100 grams. These numbers are high enough that portion control matters if you’re watching your total intake.
How Cooking Lowers Oxalate Content
Boiling is the most effective way to reduce the oxalate in any vegetable. It pulls soluble oxalate out into the cooking water, reducing levels by 30 to 87% depending on the vegetable. Steaming is less effective, cutting oxalate by only 5 to 53%. Baking does essentially nothing, at least for the foods tested.
This means that even moderate-oxalate vegetables can become low-oxalate options if you boil them and discard the water. It also means that how you prepare a vegetable matters as much as which vegetable you choose. A boiled portion of a borderline vegetable could easily end up lower in oxalate than a raw serving of something that starts out near the cutoff.
Why Oxalates Matter for Mineral Absorption
Oxalate binds to calcium and magnesium in your gut, forming insoluble compounds that your body can’t absorb. This is the mechanism behind calcium oxalate kidney stones: when excess oxalate reaches the kidneys, it combines with calcium there instead. Eating calcium-rich foods alongside oxalate-containing meals actually helps, because the calcium binds the oxalate in your digestive tract before it ever reaches the kidneys. This is why dietary calcium is protective rather than harmful for stone formers, a point that surprises many people.
If you’re pairing low-oxalate vegetables with a calcium source (dairy, fortified plant milk, or calcium-set tofu), you’re getting the double benefit of absorbing more of the calcium from your food while also neutralizing whatever small amount of oxalate is present. Reducing dietary fat may also increase calcium-oxalate binding in the gut, further lowering absorption.
Building Meals Around Low-Oxalate Vegetables
The practical takeaway is that a low-oxalate diet doesn’t require much sacrifice in the vegetable department. Stir-fries built on bok choy, broccoli, bell peppers, and mushrooms are well within safe limits. Salads made with romaine or iceberg lettuce, cucumbers, and radishes are negligible in oxalate. Roasted cauliflower, sautéed zucchini, and steamed cabbage are all solid staples.
The main adjustment is replacing spinach, beets, and Swiss chard with alternatives like kale and bok choy for your leafy green needs. Given that kale delivers just 2 mg of oxalate per cup compared to spinach’s potential 800-plus mg per 100 grams, the swap is dramatic in its impact and minimal in its effort. If you’re working within the 40 to 50 mg daily limit recommended for kidney stone patients, filling your plate with the vegetables listed above leaves plenty of room for oxalate from grains, nuts, and other parts of your diet.