Oxalate reference · Leafy greens
Oxalate in spinach
493 mg in a 1/2 cup serving, which the Oxalosis and Hyperoxaluria Foundation bands as very high. That is 567 mg per 100 g. It sits above 81 of the 83 foods with a page here.
What is worth knowing about spinach
Spinach is the food the whole oxalate conversation is built around, and it earns it: one cooked half cup carries more oxalate than most people eat in a day from everything else combined. Boiling and discarding the water removes a useful share, which is why the figure below is for cooked spinach rather than raw. What it does not do is turn spinach into a low-oxalate food.
The published figure
| As listed | Band | mg per 100 g | Serving | mg per serving |
|---|---|---|---|---|
| Spinach, fresh or frozen, boiled or steamed | very high | 567 | 1/2 cup | 493 |
Bands are per serving as the OHF lists them, so a food can be high per 100 g and low in the portion anybody eats. Turmeric and dried parsley are the clearest cases of that, and neither is a problem in a kitchen.
Lower than spinach, and doing the same job
Ranked by the most representative form of each, spinach is 9 of 9 in leafy greens. These are the ones beneath it, which matters because a substitute is only useful if it does the same thing on the plate.
| Food | Band | mg per serving | Serving |
|---|---|---|---|
| Rocket (arugula) | low | 1 | 1 cup |
| Kale | low | 3 | 1 cup |
| Lettuce | low | 3 | 1 cup, shredded |
| Cabbage | low | 4 | 1 cup |
| Mustard greens | low | 5 | 1/2 cup, chopped |
| Turnip greens | low | 6 | 1/2 cup, chopped |
| Collard greens | low | 21 | 1/2 cup |
| Swiss chard (silverbeet) | high | 237 | 1 cup |
| Spinach (this page) | very high | 493 | 1/2 cup |
Before you act on the number
A figure in a table is not a figure in your urine. Oxalate in a plant moves with variety, ripeness, soil, season and cooking — boiling leaches a good deal of it into water that is then poured away. What you absorb also depends on what was on the plate with it, because calcium eaten in the same meal binds oxalate in the gut so that it leaves in the stool instead of the urine.
There is no daily target on this site. The OHF publishes bands per serving, not an allowance, and what any one person should aim for depends on their stone chemistry and their own testing. If you have been given a number, that number wins over anything here.
Restriction is not the first move. Guideline advice for recurrent calcium oxalate stones starts with fluid, with normal calcium taken alongside meals, and with less sodium — and it recommends the fruit and vegetables a low-oxalate list tends to strip out.
All 83 foods, and the full published table · Why a low-oxalate list is the wrong tool for planning a diet · Why calcium belongs with the meal, not off the plate
