Oxalate for kidney-stone formers

In the body: Oxalate is what most kidney stones are made of.

Not rated by dose: a flag on 19 reviewed foods, among them raw rhubarb, quinoa and Cashews, raw. The list below has a line for each of 20 preparations.

For some people. Allergies, medicines and medical conditions: a flag for the people the source names, no wider.

All hazards

The reference value and where it comes from

The agency’s figureno agency dose value
Basisadvice for people who form calcium-oxalate stones
Source ?Siener 2021

Reviewed foods that carry it

19 reviewed foods carry it; none is rated by dose. A food counts once, as in the foods list: preparations sharing a page (raw and cooked, canned) count once; one with its own page counts apart. Below, one line for each of 20 preparations.

How often you can eat it ?

No food here is rated by dose. Each line says why it’s listed: a flag for the people the source names, advice on handling it, or context.

Flags and context, not rated by dose

Almond butter
Not rated yet
57.5 mg
per serving
oxalate (15 g × 383 mg/100 g)
Siener 2021 · grade B ?
How it’s rated
Not rated: no agency sets an intake limit for oxalate, so this is a value only, of interest to people who form calcium-oxalate stones. Almonds are listed at 383 mg/100 g (two secondary sources give 383–407), so a 15.0 g serving of almond butter carries about 57.5 mg, in the 'moderate' class (25–99 mg a serving) of the Oxalosis and Hyperoxaluria Foundation list. No almond-butter value exists in the sources; the whole-almond figure is carried over.
Intake: one 15.0 g serving a day, 70 kg adult · Level in the food: 383 mg/100 g (listing) (compiled value for almonds (raw); two secondary sources 383-407 mg/100 g)
Measured on: Siener 2021 Table 3 / Mitchell 2020 Table 1 as the parent row; whole almonds
Almonds, raw
Not rated yet
114.9–122 mg
per serving
total oxalate per 30 g serving
Siener 2021 · grade B ?
How it’s rated
Not rated: no agency sets an intake limit for oxalate, so this is a value only, of interest to people who form calcium-oxalate stones. Almonds are listed at 383-407 mg total oxalate per 100 g in two secondary sources, so a 30 g serving carries about 115-122 mg.
Intake: one 30 g serving a day, 70 kg adult · Level in the food: 383 mg/100 g (compiled values: 383 and 407 mg/100 g in two secondary sources)
Measured on: Total oxalate 383-407 mg/100 g in two secondary sources (Hönow & Hesse as relayed in Siener 2021 Table 3; the Harvard list as relayed in Mitchell 2020 Table 1); no primary analysis opened
Brazil nuts, raw
Not rated yet
54.3 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated for calcium-oxalate stone formers: the only source is a patient-foundation list with no stated method (Oxalosis and Hyperoxaluria Foundation, Feb 2024), and no measured value was found. A 30 g serving carries 54.3 mg oxalate, a moderate portion by that list's own bands (25-99 mg).
Intake: 30 g serving · Level in the food: 181 mg oxalate/100 g (compiled list value)
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Nuts, Brazil Nuts, raw or roasted'; no primary analysis cited
Cashews, raw
Not rated yet
74.7 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated for calcium-oxalate stone formers: the only source is a patient-foundation list with no stated method. A 30 g serving carries 74.7 mg oxalate, a moderate portion by the list's own bands (25-99 mg); the list gives 249 mg per 100 g, the highest of walnuts, cashews and Brazil nuts.
Intake: 30 g serving · Level in the food: 249 mg oxalate/100 g (compiled list value)
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Nuts, Cashew, raw or roasted'; no primary analysis cited
Chia seeds
Not rated yet
70.5 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated for calcium-oxalate stone formers: the only source is a patient-foundation list (one brand, no stated method). A 15.0 g serving carries 70.5 mg oxalate, a moderate portion by the list's bands (25-99 mg); 100 g would be in its very-high band.
Intake: 15 g serving · Level in the food: 470 mg oxalate/100 g (compiled list value (one brand))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Seeds, Chia, Bob's Red Mill'
Chia seeds, ground
Not rated yet
70.5 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated: no agency sets an oxalate intake limit; this is information for people who form calcium-oxalate stones. A patient-foundation list gives 470 mg/100 g for one brand, with no stated method, so 15 g carries 70.5 mg, a moderate portion by the list's bands (25–99 mg); 100 g would fall in its very-high band.
Intake: 15 g serving · Level in the food: 470 mg/100 g (listing) (compiled list value (one brand))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Seeds, Chia, Bob's Red Mill'
Dried cranberries, sweetened
Not rated yet
5.2 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade C ?
How it’s rated
Not rated: no agency sets an oxalate intake limit; this is information for people who form calcium-oxalate stones. A patient-foundation list gives 13 mg/100 g for dried cranberries (Craisins), so a 40 g serving carries 5.2 mg, well under the list's 25 mg 'moderate' line; a second line for dried cranberries says 2 mg/100 g, and fresh cranberries are listed at 4 mg/100 g. The list gives no method per line.
Intake: one 40 g serving · Level in the food: 13 mg oxalate/100 g (compiled list value ('Berries, Craisins, dried'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (2024), fruit table; 'Craisins, dried' 13 mg per 100 g, 5 mg per serving; a second line 'Cranberries, dried' gives 2 mg per 100 g. The list gives no method or source per line.
Kale, raw
Not rated yet
8.5 mg
per serving
oxalate (85 g × 10 mg/100 g)
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated: oxalate matters to people who form oxalate stones, so it is person-specific. Raw kale is listed at 10 mg per 100 g (8.5 mg in an 85 g serving; boiled 5), in the low-oxalate class under 25 mg a serving. Sources disagree: a Korean HPLC survey found none, while a search result citing USDA suggests about 18–39 mg per 100 g (column mapping unverified).
Intake: not applicable (person-specific) · Level in the food: 10 mg/100 g (listing) (compiled list value (OHF 'Avg oxalate per 100 g'), raw kale (boiled: 5))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list 2024, line 'Kale, Variety, Raw'; the Salgado 2023 review Table 5 lists raw kale oxalate as not detected (total, soluble), citing a Korean HPLC study
Medjool dates
Not rated yet
3.2 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade C ?
How it’s rated
Not rated: no agency sets an oxalate intake limit; this is information for people who form calcium-oxalate stones. A patient-foundation list gives 8 mg/100 g for chopped dates, so a 40 g serving carries 3.2 mg, low on the list's own scale (under 25 mg a serving). Cultivar and method are not given.
Intake: one 40 g serving · Level in the food: 8 mg oxalate/100 g (compiled list value ('Dates, Chopped'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (2024), fruit table, 'Dates, Chopped' 8 mg per 100 g, 4 mg per its serving. Cultivar and method not given.
Pistachios, dry-roasted
Not rated yet
12.6 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated: the only figure is 42 mg oxalate per 100 g from a patient-foundation list (Oxalosis and Hyperoxaluria Foundation, 2024) that cites no primary analysis and states no method. For people who form calcium-oxalate stones, a 30 g serving works out to 12.6 mg, under the list's own 25 mg low-oxalate line.
Intake: 30 g serving · Level in the food: 42 mg oxalate/100 g (compiled list value ('avg oxalate per 100 g'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Nuts, Pistachio, raw or roasted'; no primary analysis cited
Popcorn, air-popped
Not rated yet
16.5 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated: the only figure is 33 mg oxalate per 100 g from a patient-foundation list with no stated method. For people who form calcium-oxalate stones, a 50 g popped serving works out to 16.5 mg, under the list's own 25 mg low-oxalate line.
Intake: 50 g popped serving · Level in the food: 33 mg oxalate/100 g (compiled list value ('avg oxalate per 100 g'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Corn, Popcorn, popped'; no primary analysis cited; the list's 32 g serving of '1/4 cup' is probably unpopped kernels, so per-serving mg here is computed from the per-100 g value
Sunflower seeds, dry-roasted
Not rated yet
9 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated: the only figure is 30 mg oxalate per 100 g from a patient-foundation list with no stated method. For people who form calcium-oxalate stones, the list gives 9 mg for its 29 g serving, under its own 25 mg low-oxalate line.
Intake: 30 g serving · Level in the food: 30 mg oxalate/100 g (compiled list value ('avg oxalate per 100 g'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Seeds, Sunflower, raw or roasted'; no primary analysis cited
Walnuts, raw
Not rated yet
18.6 mg
per serving
oxalate
Oxalosis and Hyperoxaluria Foundation 2024 · grade B ?
How it’s rated
Not rated, for calcium-oxalate stone formers: the only figure is a patient-foundation list (Oxalosis and Hyperoxaluria Foundation, February 2024), 62 mg oxalate per 100 g, with no stated method. A 30 g serving is 18.6 mg, which the list's own bands call a low-oxalate portion (under 25 mg).
Intake: 30 g serving · Level in the food: 62 mg oxalate/100 g (compiled list value ('avg oxalate per 100 g'))
Measured on: Oxalosis and Hyperoxaluria Foundation oxalate list (Feb 2024), 'Nuts, Walnuts, raw or roasted'; no primary analysis cited
Beets, cooked
Context
31.4 mg
per serving
Salgado 2023 · grade B ?
How it’s rated
Shown as context, not rated: no agency sets an oxalate intake limit; this is information for people who form calcium-oxalate stones. An 85 g serving of boiled beets carries about 31 mg total oxalate (36.9 mg/100 g, from two measurements), and other boiled-beet figures give 44–65 mg, in the 'moderate' class (25–99 mg a serving) of the Oxalosis and Hyperoxaluria Foundation list.
Intake: one 85 g serving a day, 70 kg adult · Level in the food: 369 mg/kg (mean of n 2 (HPLC-enzyme-reactor, as relayed); range of boiled-beet studies 369-760 mg/kg total oxalate, n = 2)
Measured on: Boiled beetroot, total oxalate 36.9 mg/100 g FW (soluble 16.3), Hönow & Hesse as relayed in Salgado 2023 Table 5; other boiled-beet rows: 52 mg/100 g (ref 36), 76.0 (ref 32); OHF list 57 mg/100 g
Black tea, brewed
Context
14.4 mg
per serving
oxalate per 250 mL
Siener 2021 · grade B ?
How it’s rated
Value only: the verdict belongs to method rule 4 (oxalate cap). 14.4 mg per cup. Urinary recovery (bioavailability) 3.2% in this study (n = 10 healthy men); 0.08%, 1.9-4.7% and 2.4% in earlier studies it cites.
Intake: one 250 mL (250 g) cup a day, 70 kg adult · Level in the food: 57.5 mg/L (single brewed batch (study tea), n = 1)
Measured on: Siener & Hesse 2021: black tea brewed 12 tea bags x 1.75 g (21 g) in 1.5 L of 70 °C water, 5 min; oxalate content 57.5 mg/L (soluble oxalate in the paper's discussion)
Green tea, brewed
Context
1.4 mg
per serving
oxalate per 250 mL
Charrier 2002 · grade A ?
How it’s rated
Shown as context, not rated: oxalate matters for people who form calcium oxalate stones. Green tea averages 5.55 mg/L (4 tea bags), 1.36 mg of soluble oxalate in a 245 mL cup and about 1.4 mg per 250 mL; black tea is the oxalate-rich tea (57.5 mg/L in one batch), and green is about one seventh of it.
Intake: one 250 mL (250 g) cup a day, 70 kg adult · Level in the food: 5.55 mg/L (mean of 4 green tea bags (1.36 mg soluble oxalate per 245 mL cup), n = 4)
Measured on: Charrier 2002, Christchurch NZ, 4 green tea bags, 245 mL water at 90 C for 5 min; soluble oxalate by HPLC. 1.36 mg ÷ 0.245 L = 5.55 mg/L; per 250 mL cup 1.39 mg.
Kiwi, raw
Context
27 mg
per serving
total oxalate (about 10.6 mg soluble)
PubMed 28239098 · grade B ?
How it’s rated
Shown as context, not rated: advice for people who form calcium-oxalate stones, with no dose limit. 140 g of pulp holds 27.0 mg of total oxalate (about 10.6 mg soluble), from three bulk samples of green and golden cultivars (Nguyen and Savage 2013).
Intake: one 140 g serving a day, 70 kg adult · Level in the food: 19.3 mg/100 g (total oxalate, pulp, ripe green kiwifruit (soluble 7.6 mg/100 g))
Measured on: Nguyen and Savage 2013: three bulk samples of two cultivars (green Actinidia deliciosa and golden A. chinensis) bought ripe at a local market (Christchurch, NZ); pulp is 90.4% of the edible portion; seeds hold much more (green 106.7 mg/100 g insoluble).
Quinoa, cooked
Context
Manzanilla 2024 · grade B ?
How it’s rated
Shown as context: relevant to people prone to calcium oxalate stones. No measured soluble or cooked value, so not rated.
Intake: n/a
Measured on: no measured cooked-quinoa oxalate; raw flour 397-715 mg/100 g (Manzanilla-Valdez 2024)
Rhubarb, raw
Context
Massey 1993 · grade B ?
How it’s rated
The oxalate-cap constraint: values recorded, no verdict. Per 140 g raw (derived arithmetic): total 745-1,381 mg, soluble 402-648 mg; per 85 g: 452-839 and 244-394. Boiled and drained (Savage): total 1,058 mg, soluble 113 mg per 140 g.
Intake: one 140 g serving a day (85 g is the alternative), 70 kg adult
Measured on: food-specific measured oxalate: see attributes (raw total 532-987 mg/100 g in the studies read, soluble 287-463; boiled-and-drained soluble about 81)
Soy drink, unsweetened, fortified
Context
11 mg
per serving
Siener 2021 · grade C ?
How it’s rated
Shown as context, not rated: no agency sets an intake limit for oxalate. The one figure found is 4.4 mg/100 mL (11 mg for a 250 mL serving), relayed in a 2021 review for a drink that is only 62% soy milk, so a plain fortified drink may differ. For comparison the dry soybean is 277 mg/100 g, so the drink is far lower per serving.
Intake: one 250 mL serving (250 g) a day, 70 kg adult · Level in the food: 44 mg/L (single value in a review table (4.4 mg/100 mL), product 'soybean drink, 62% soymilk')
Measured on: Siener 2021 review, Table 2 'Oxalate content of beverages', relaying its reference 56; a beverage containing 62% soy milk, not a plain fortified soy drink; method and year of the primary measurement not opened