Oxalate <25 mg/serving
Oxalate 25-99 mg/serving
Oxalate ≥100 mg/serving
📊 Nutrition at a Glance
📏 Oxalate by Serving Size
| Serving | Weight | Oxalate | Verdict |
|---|---|---|---|
| 1/2 cup | 105 g | 4 mg | Safe |
| 2 x 1/2 cup | 210 g | 8 mg | Safe |
| ½ x 1/2 cup | 52 g | 2 mg | Safe |
🏷️ Tags
🟢 See all Vegetables rated Safe for kidney stones →
⚖️ Compare this food: · vs Slippery Elm Bark →
🔗 Related Foods
🟢 Safe alternatives (recommended)
⚠️ Other foods in this category to watch
❓ Frequently Asked Questions
Can I eat Onion with kidney stones?
Safe pick. 4 mg oxalate per 1/2 cup means Onion is comfortably in the green zone. Harvard's 2024 lab data says so. No need to track this one obsessively.
What's the oxalate content of Onion?
The lab result: 4 mg per 1/2 cup (105g serving). That's 4 mg per 100g. Harvard's ion chromatography analysis, 2024. Not crowdsourced, not estimated.
Is Onion a high-oxalate food?
It's low. 4 mg per 1/2 cup is well under the 25 mg danger line. Onion is not the food you need to worry about.
What are the best low-oxalate alternatives to Onion?
Plenty of options. Scroll down to Related Foods — every 🟢 green item there is a lower-oxalate alternative to Onion. Same food group, way less oxalate.
How reliable is the data for Onion?
The oxalate number for Onion — 4 mg per serving — is from Harvard's 2024 lab analysis. That part is solid. The USDA nutrition data (sodium, protein, calcium) is still being matched — we'll update when it's available.