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

Blueberries, fresh or frozen

🟡 Caution — Moderate
27 mg oxalate / serving
Serving: 1 cup (200 g) | Per 100 g: 14 mg
✓ Medically Reviewed Content reviewed by OxalateWatch Editorial Team. Based on Harvard T.H. Chan SPH oxalate data (2024) and NKF/AUA dietary guidelines.

Blueberries sit right on the edge between Safe and Caution territory — 27 mg oxalate per cup, just 2 mg above the 25 mg safe threshold. This makes them one of the most interesting foods in the Harvard database: not dangerous enough to avoid, not low enough to ignore. For most kidney stone patients, a half-cup of blueberries (about 14 mg) on oatmeal or yogurt is completely fine. A full cup every single day could push your daily oxalate total higher than you realize — especially if you combine them with other moderate-oxalate foods like whole wheat toast or sweet potatoes. Blueberries aren't a problem food — they're a portion-awareness food. Pair them with yogurt or milk for calcium binding, and watch your portion size.

📊 Nutrition at a Glance

27 mg
Oxalate / serving
Moderate
2 mg
Sodium / 100g
Low Na
0.7 g
Protein / 100g
Tier 1
12 mg
Calcium / 100g
Tier 1

📏 Oxalate by Serving Size

ServingWeightOxalateVerdict
1 cup200 g27 mg Caution
2 x 1 cup400 g54 mg Caution
½ x 1 cup100 g13.5 mg Safe

🏷️ Tags

Fruits 🟡 Oxalate Caution Moderate Oxalate Plant-Based Calcium-Rich

🟡 See all Fruits rated Caution for kidney stones →

⚖️ Compare this food: · vs Peach · vs Plum

🔗 Related Foods

❓ Frequently Asked Questions

Should I avoid Blueberries if I have kidney stones?

Yellow zone. 27 mg per 1 cup means Blueberries sits in that middle ground where it's manageable but not risk-free. Half portions help. So does eating it less often.

What's the oxalate content of Blueberries?

Quick math: 1 cup of Blueberries = 27 mg oxalate. 100g = 14 mg. Both numbers come from Harvard's latest lab measurements. Not AI, not a database, actual lab work.

Is Blueberries high in oxalates?

Moderate. Blueberries has 27 mg oxalate per 1 cup — not high enough to panic, not low enough to ignore. Portions matter with this one.

What are the best low-oxalate alternatives to Blueberries?

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

How much Blueberries is safe to eat?

Think garnish, not main dish. Blueberries at 27 mg per 1 cup is a lot for one food. Use smaller amounts spread across meals or as a flavor accent rather than the centerpiece.

How much sodium does Blueberries have?

Low sodium: 2 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

📚 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.