Is Buckwheat Flour Safe for Kidney Stones? (Caution)
mg oxalate
per serving
Serving: 1/4 cup (30 g)
Verdict: 🟡 Caution
Per 100g: 280 mg
Data: Harvard T.H. Chan SPH (2024)
Here's the takeaway: Buckwheat Flour falls in the Caution band (🟡) at 84 mg oxalate per serving. Not off-limits, but not free — moderate portions, a few times a week at most, and preferably with dairy or another calcium source at the same meal.
Putting Buckwheat Flour in context: it lands well above the category average of 14 mg. In the database, 84% of grains & pasta (170 of 201) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical grains & pasta here averages 14 mg oxalate per serving, so Buckwheat Flour runs 505% 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 grains & pasta 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 context, Buckwheat Flour measures 84 mg per 1/4 cup, rated Caution.
Can I eat this food every day?
Daily eating is fine for Safe foods (under 25 mg/serving). For Caution or Avoid foods, spread them out and alternate with low-oxalate picks. The idea is keeping your weekly oxalate load manageable, not eliminating any single food. For Buckwheat Flour, the measured oxalate value is 84 mg per 1/4 cup (Caution).
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 Buckwheat Flour, the measured oxalate value is 84 mg per 1/4 cup (Caution).
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 Buckwheat Flour, the measured oxalate value is 84 mg per 1/4 cup (Caution).