Is Sweet potato Safe for Kidney Stones? (Caution)
mg oxalate
per serving
Serving: 1/2 cup, mashed (134 g)
Verdict: 🟡 Caution
Per 100g: 42 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for Sweet potato: Caution (🟡) at 56 mg oxalate per serving. It's the middle of the road — usable, but with guardrails. Half portions, occasional frequency, calcium pairing, and watching your total daily intake keeps it workable.
Putting Sweet potato in context: it lands well above the category average of 27 mg. In the database, 80% of vegetables (219 of 271) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical vegetables here averages 27 mg oxalate per serving, so Sweet potato runs 107% above that baseline. That places it on the higher end for oxalate in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all vegetables rated Caution for a full side-by-side.
Why does the safe threshold matter?
The 25 mg per serving threshold is based on clinical guidance for kidney stone patients. Harvard's lab data (2024) provides the most reliable oxalate measurements available — no database estimates, direct lab analysis. For Sweet potato, the measured oxalate value is 56 mg per 1/2 cup, mashed (Caution).
Can I eat this food every day?
If it's in the Safe zone (under 25 mg/serving), yes — it can be a regular part of your diet. For Caution or Avoid foods, frequency matters. Rotate them with lower-oxalate options throughout the week. For context, Sweet potato measures 56 mg per 1/2 cup, mashed, rated Caution.
Where does the oxalate data come from?
The numbers come from Harvard T.H. Chan SPH's 2024 laboratory measurements, published through the OHF database. Direct lab analysis, which is why they're treated as the reference values for food oxalate. For context, Sweet potato measures 56 mg per 1/2 cup, mashed, rated Caution.
Should I also check sodium and calcium?
Definitely. Oxalate is only part of the story — high sodium raises calcium in urine, and dietary calcium (from food, not pills) binds oxalate in the gut. The food's main page lists both, so it's worth checking before you plan around it. For Sweet potato, the measured oxalate value is 56 mg per 1/2 cup, mashed (Caution).