🟢 Safe
Oxalate <25 mg/serving
🟡 Caution
Oxalate 25-99 mg/serving
🔴 Avoid
Oxalate ≥100 mg/serving
🟢

Fennel bulb, raw

🟢 Safe — Low Oxalate
1 mg oxalate / serving
Serving: 1 cup sliced (87 g) | Per 100 g: 0 mg
✓ Medically Reviewed Content reviewed by OxalateWatch Editorial Team. Based on Harvard T.H. Chan SPH oxalate data (2024) and NKF/AUA dietary guidelines.

📊 Nutrition at a Glance

1 mg
Oxalate / serving
Low Oxalate
Sodium / 100g
Pending
Protein / 100g
Pending
Calcium / 100g
Pending

📏 Oxalate by Serving Size

ServingWeightOxalateVerdict
1 cup sliced87 g1 mg Safe
2 x 1 cup sliced174 g2 mg Safe
½ x 1 cup sliced43 g0.5 mg Safe

🏷️ Tags

Vegetables 🟢 Oxalate Safe Low Oxalate Plant-Based

🟢 See all Vegetables rated Safe for kidney stones →

🔗 Related Foods

❓ Frequently Asked Questions

Should I avoid Fennel bulb if I have kidney stones?

Safe pick. 1 mg oxalate per 1 cup sliced means Fennel bulb is comfortably in the green zone. Harvard's 2024 lab data says so. No need to track this one obsessively.

How much oxalate is in Fennel bulb?

The lab result: 1 mg per 1 cup sliced (87g serving). That's 0 mg per 100g. Harvard's ion chromatography analysis, 2024. Not crowdsourced, not estimated.

Is Fennel bulb a high-oxalate food?

It's low. 1 mg per 1 cup sliced is well under the 25 mg danger line. Fennel bulb is not the food you need to worry about.

What can I eat instead of Fennel bulb?

Substitutes exist. The safe alternatives listed below are all low-oxalate foods in the same family as Fennel bulb. Grab one of those and you dodge the oxalate while keeping similar flavors.

How reliable is the data for Fennel bulb?

The oxalate number for Fennel bulb — 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.

🔍 Explore More About This Food

📚 Data Sources

Oxalate: Harvard T.H. Chan School of Public Health (2024) via OHF.

📖 Key Scientific References

Taylor EN, Curhan GC. Oxalate intake and the risk for nephrolithiasis. J Am Soc Nephrol. 2007;18(7):2198-2204. PMID: 17538185
Borghi L, Schianchi T, Meschi T, et al. Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria. N Engl J Med. 2002;346(2):77-84. DOI: 10.1056/NEJMoa010369
Fink HA, Akornor JW, Garimella PS, et al. Diet, fluid, or supplements for secondary prevention of nephrolithiasis. Eur Urol. 2009;56(1):72-80. DOI: 10.1016/j.eururo.2009.03.031
Ferraro PM, Taylor EN, Gambaro G, Curhan GC. Dietary and lifestyle factors for primary prevention of nephrolithiasis. BMC Nephrol. 2020;21(1):267. PMID: 32652950
Pearle MS, Goldfarb DS, Assimos DG, et al. Medical management of kidney stones: AUA guideline. J Urol. 2014;192(2):316-324. DOI: 10.1016/j.juro.2014.05.006
Liebman M, Costa G. Effects of calcium and magnesium on urinary oxalate excretion after oxalate loads. J Urol. 2000;163(5):1565-1569. PMID: 10751889
Holmes RP, Assimos DG. The impact of dietary oxalate on kidney stone formation. Urol Res. 2004;32(5):311-316. DOI: 10.1007/s00240-004-0437-3
Lin BB, Lin ME, Huang RH, et al. Dietary treatment and fluid intake for prevention of recurrent calcium stones. PLoS One. 2021;16(4):e0250257. PMID: 33872340
This is dietary reference information, NOT medical advice. Talk to your doctor or a registered dietitian before changing your diet. Oxalate tolerance varies by person, stone type, and medication.