Oxalate <25 mg/serving
Oxalate 25-99 mg/serving
Oxalate ≥100 mg/serving
Onions are the foundation of cooking across almost every cuisine on earth, and they're essentially zero oxalate — about 4 mg per half-cup, and you rarely eat that much onion at once. Use them freely. Saute them as a base for soups, stews, and stir-fries. Caramelize them for depth. Eat them raw on burgers, tacos, and salads. The sulfur compounds that make you cry when cutting onions are the same ones that give them their health benefits. No oxalate concerns, no sodium concerns, no protein concerns. Onions are a pure win for kidney stone patients. If every food were as safe as onions, this website wouldn't need to exist.
📊 Nutrition at a Glance
📏 Oxalate by Serving Size
| Serving | Weight | Oxalate | Verdict |
|---|---|---|---|
| 1 tsp | 2 g | 1 mg | Safe |
| 2 x 1 tsp | 4 g | 2 mg | Safe |
| ½ x 1 tsp | 1 g | 0.5 mg | Safe |
🏷️ Tags
🟢 See all Vegetables rated Safe for kidney stones →
⚖️ Compare this food: · vs Nopal (Prickly Pear) · vs Bitter Gourd (Bitter Melon) →
🔗 Related Foods
🟢 Safe alternatives (recommended)
⚠️ Other foods in this category to watch
❓ Frequently Asked Questions
Is Onion powder safe for kidney stones?
Don't overthink this one. Onion powder has 1 mg oxalate per 1 tsp. That's solidly safe territory for kidney stones. The number is from Harvard's latest lab work.
What's the oxalate content of Onion powder?
One 1 tsp of Onion powder = 1 mg oxalate. Scale it up to 100g and you're at 50 mg. Direct measurement from Harvard, 2024. About as reliable as food data gets.
Is Onion powder low or high oxalate?
Low. 1 mg per 1 tsp puts Onion powder firmly in the low-oxalate category. Safe for regular eating if you're managing kidney stones.
What are the best low-oxalate alternatives to Onion powder?
Don't give up the whole category — just pick a safer member of it. The green foods in the related section all work as substitutes for Onion powder with a fraction of the oxalate.
How reliable is the data for Onion powder?
The oxalate number for Onion powder — 1 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.