Is Corn syrup Safe for Kidney Stones? (Safe)
mg oxalate
per serving
Serving: 1 tbsp (20 g)
Verdict: 🟢 Safe
Per 100g: 0 mg
Data: Harvard T.H. Chan SPH (2024)
What this means: Corn syrup is rated Safe (🟢). At 0 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.
Among grains & pasta, Corn syrup sits well below the category average of 14 mg. For context, 170 out of 201 grains & pasta (84%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average grains & pasta in our database has 14 mg oxalate per serving — which means Corn syrup is 100% below the category norm. Within its specific category, Corn syrup ranks among the lower-oxalate options. 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 grains & pasta rated Safe to compare within the same verdict level.
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 Corn syrup: 0 mg oxalate per 1 tbsp — Safe per Harvard (2024).
Can I eat this food every day?
For Safe foods (under 25 mg/serving), daily use is generally fine. Caution and Avoid foods work better as occasional items — rotate them with safer options so no single high-oxalate food becomes a habit. Applied to Corn syrup: 0 mg oxalate per 1 tbsp — Safe per Harvard (2024).
Where does the oxalate data come from?
Harvard T.H. Chan School of Public Health (2024) via the OHF database. These are direct laboratory measurements — the most reliable oxalate data available for food. Corn syrup comes in at 0 mg oxalate per 1 tbsp (Safe) in the measured database.
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. Corn syrup comes in at 0 mg oxalate per 1 tbsp (Safe) in the measured database.