Spinach — Low or High Oxalate?
mg oxalate
per serving
Serving: 1/2 cup (87 g)
Verdict: 🔴 Avoid
Per 100g: 567 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Spinach is rated Avoid (🔴). At 493 mg oxalate per serving, Spinach exceeds the 100 mg threshold. Kidney stone patients should limit or avoid this food. If you do eat it, keep portions very small, pair it with calcium, and drink extra water. Check the full food page for safer alternatives.
Among vegetables, Spinach sits well above the category average of 27 mg. For context, 219 out of 271 vegetables (80%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average vegetables in our database has 27 mg oxalate per serving — which means Spinach is 1724% above the category norm. Within its specific category, Spinach ranks on the higher end for oxalate. This context matters because two 'Safe' foods can have very different oxalate levels — one might have 5 mg while another has 24 mg. Both are Safe, but the first gives you more dietary flexibility. Browse all vegetables rated Avoid to compare within the same verdict level.
What's the difference between 'Low' and 'Safe'?
Low Oxalate means under 25 mg per serving — the same threshold as Safe. They're equivalent in practice. The verdict system uses Low/Moderate/High to describe oxalate categories and Safe/Caution/Avoid to recommend dietary action.
Can oxalate levels change with cooking?
Yes. Boiling and discarding water can reduce soluble oxalate by 30-50% in many vegetables. Check the food's main page or cooking-specific angle page for details on preparation effects.
Is 'Low Oxalate' the same as 'No Oxalate'?
No — almost all plant foods contain some oxalate. 'Low Oxalate' means under 25 mg per serving, which is considered safe for kidney stone patients. Only purified products like sugar, oil, and salt have near-zero oxalate.