Is portobello Safe for Kidney Stones? (Safe)
mg oxalate
per serving
Serving: 1 cup sliced (121 g)
Verdict: 🟢 Safe
Per 100g: 1.7 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for portobello: Safe (🟢), with 2 mg oxalate per serving — comfortably below the 25 mg safe cutoff. There's no need to limit it. Just keep your usual kidney stone basics in place: water throughout the day and calcium-rich foods at meals.
Putting portobello in context: it lands well below 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 portobello runs 93% below that baseline. That places it among the lower-oxalate options 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 Safe 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. Applied to portobello: 2 mg oxalate per 1 cup sliced — Safe per Harvard (2024).
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, portobello measures 2 mg per 1 cup sliced, rated Safe.
Where does the oxalate data come from?
Every oxalate figure is sourced from Harvard T.H. Chan SPH (2024), distributed via the OHF database. The values come from actual lab measurements of the foods — not from database averages or estimates. For portobello, the measured oxalate value is 2 mg per 1 cup sliced (Safe).
Should I also check sodium and calcium?
Yes — oxalate alone doesn't decide stone risk. Sodium pushes more calcium into urine, and calcium from food (not supplements) helps bind oxalate during digestion. The main food page covers sodium and calcium alongside oxalate. For context, portobello measures 2 mg per 1 cup sliced, rated Safe.