How Much Oxalate Is in Fish and Seafood?

Harvard's 2024 analysis found 3 mg of oxalate in one serving of Fish and Seafood (4 oz). At the 100-gram level, that's 3 mg. This puts Fish and Seafood in the Safe range (under 25 mg per serving). Keep in mind: oxalate varies by growing conditions, preparation method, and variety — but Harvard's measurement is the most reliable reference available.

✓ Medically Reviewed Based on Harvard T.H. Chan SPH oxalate data (2024) and NKF/AUA dietary guidelines.

3
mg oxalate
per serving

Food: Fish and Seafood, Variety
Serving: 4 oz (113 g)
Verdict: 🟢 Safe
Per 100g: 3 mg
Data: Harvard T.H. Chan SPH (2024)

🔄 Lower-Oxalate Alternatives

💡 What This Means for Your Diet

What this means: Fish and Seafood is rated Safe (🟢). At 3 mg oxalate per serving, it's well under the 25 mg safety threshold. You can include it regularly in a kidney stone diet. Pair it with calcium-rich foods (dairy, fortified plant milks) for additional protection, and drink plenty of water throughout the day.

📊 How Fish and Seafood Compares

Among seafood, Fish and Seafood sits well above the category average of 2 mg. For context, 55 out of 55 seafood (100%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average seafood in our database has 2 mg oxalate per serving — which means Fish and Seafood is 94% above the category norm. Within its specific category, Fish and Seafood ranks on the higher end for oxalate. This context matters because two 'Safe' foods can have very different oxalate levels — one might have 5 mg while another has 24 mg. Both are Safe, but the first gives you more dietary flexibility. Browse all seafood rated Safe to compare within the same verdict level.

❓ Related Questions

Why does oxalate per 100g matter?

The per-100g number lets you compare foods on an equal-weight basis, regardless of serving size. It's useful when two foods have very different typical serving sizes, or when you eat more or less than a standard serving.

How accurate is the oxalate measurement?

Harvard's 2024 analysis used ion chromatography — the gold standard for oxalate measurement. These are direct lab values, not estimates or database calculations. Variability exists between samples, but this is the most reliable reference available.

How does this compare to other foods?

Foods under 25 mg per serving are rated Safe. Foods between 25-99 mg are Caution. 100+ mg is Avoid. Check the food's category page on OxalateWatch to see how it compares to similar foods.

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.