Is Flour Safe for Kidney Stones? | Safe

Q: Should I avoid Flour if I have kidney stones?

Don't overthink this one. Flour has 20 mg oxalate per 1/4 cup. That's solidly safe territory for kidney stones. The number is from Harvard's latest lab work.

Q: What's the oxalate content of Flour?

Here are the numbers: 20 mg oxalate in one 1/4 cup of Flour (34g). Per 100 grams, that's 58 mg. Harvard T.H. Chan SPH did the lab work (2024) — these aren't database guesses.

Q: Is Flour low or high oxalate?

Nope. Flour is a low-oxalate food — just 20 mg per 1/4 cup. Well under the 25 mg cutoff. You're in the clear with this one.

Q: What can I eat instead of Flour?

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 Flour with a fraction of the oxalate.

Q: How much sodium does Flour have?

Low sodium: 0 mg/100g. That's a non-issue for kidney stones. Just don't undo it by drowning it in salt during cooking.

🟢 Safe
Oxalate <25 mg/serving

🟡 Caution
Oxalate 25-99 mg/serving

🔴 Avoid
Oxalate ≥100 mg/serving

✓ 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

20 mg

Oxalate / serving

Low Oxalate

0 mg

Sodium / 100g

Low Na

14.5 g

Protein / 100g

Tier 1

30 mg

Calcium / 100g

Tier 1

📏 Oxalate by Serving Size

Serving	Weight	Oxalate	Verdict
1/4 cup	34 g	20 mg	Safe
2 x 1/4 cup	68 g	40 mg	Caution
½ x 1/4 cup	17 g	10 mg	Safe

🏷️ Tags

🟢 See all Grains & Pasta rated Safe for kidney stones →

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❓ Frequently Asked Questions

Should I avoid Flour if I have kidney stones?

Don't overthink this one. Flour has 20 mg oxalate per 1/4 cup. That's solidly safe territory for kidney stones. The number is from Harvard's latest lab work.

What's the oxalate content of Flour?

Here are the numbers: 20 mg oxalate in one 1/4 cup of Flour (34g). Per 100 grams, that's 58 mg. Harvard T.H. Chan SPH did the lab work (2024) — these aren't database guesses.

Is Flour low or high oxalate?

Nope. Flour is a low-oxalate food — just 20 mg per 1/4 cup. Well under the 25 mg cutoff. You're in the clear with this one.

What can I eat instead of Flour?

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 Flour with a fraction of the oxalate.

How much sodium does Flour have?

Low sodium: 0 mg/100g. That's a non-issue for kidney stones. Just don't undo it by drowning it in salt during cooking.

🔍 Explore More About This Food

🟢See our detailed safety analysis for this food 📊Exact oxalate numbers: how much is in a serving 📋Low, moderate, or high oxalate? Full breakdown 🧂How much sodium? Kidney stone risk check

📚 Data Sources

Oxalate: Harvard T.H. Chan School of Public Health (2024) via OHF. Nutrition: USDA FoodData Central (SR Legacy 2018 & Foundation Foods).

📖 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.

Flour, Spelt