Is Oyster Safe for Kidney Stones? (Safe)
mg oxalate
per serving
Serving: 1 oz (28 g)
Verdict: 🟢 Safe
Per 100g: 22 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for Oyster: Safe (🟢), with 6 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 Oyster in context: it lands well above the category average of 2 mg. In the database, 100% of seafood (55 of 55) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical seafood here averages 2 mg oxalate per serving, so Oyster runs 288% 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 seafood 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. For context, Oyster measures 6 mg per 1 oz, rated Safe.
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. Applied to Oyster: 6 mg oxalate per 1 oz — Safe per Harvard (2024).
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, Oyster measures 6 mg per 1 oz, rated Safe.
Should I also check sodium and calcium?
Yes — kidney stone risk isn't just about oxalate. High sodium increases urinary calcium (a stone promoter). Adequate dietary calcium (from food, not supplements) actually binds oxalate in your gut. Check the food's full nutrition page for the complete picture. For Oyster, the measured oxalate value is 6 mg per 1 oz (Safe).