Palak paneer: the paneer carries the calcium, the spinach carries little

The usual worry about palak paneer is that the cheese blocks the iron in the spinach. By a meta-analysis of randomized and crossover trials, mostly at supplement doses rather than in a meal like this one, extra calcium lowered short-term iron absorption by about 5.6 percentage points (95% CI 4.0 to 7.1), and hemoglobin did not fall. The larger point is that spinach was never much of a mineral source. In a crossover trial on 13 adults, with single test meals in 1988, spinach gave up 5.1 percent of its calcium against 27.6 percent from milk at the same dose. NIH lists spinach iron as poorly absorbed because of inhibitors such as polyphenols. The calcium in this dish comes from the paneer, 537 mg per 3.5 oz (100 g) in UK tables. A 200 g cup of the USDA standard recipe gives about 202 calories, 120 mg of calcium and 484 mg of sodium, a midpoint only, since home and restaurant versions vary in cream, ghee and paneer.

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• USDA's survey recipe for palak paneer gives 101 calories, 60 mg calcium, 0.55 mg iron and 242 mg sodium per 3.5 oz (100 g). — USDA FNDDS record Palak Paneer, fdc_id 2709631 (n = 1 record) Evidence E source
  Per 100 g: energy 101 calories, calcium 60 mg, iron 0.55 mg, sodium 242 mg
• Paneer brings most of the dish's calcium and fat: UK tables list 537 mg calcium, 26 g protein and 24.5 g fat per 3.5 oz (100 g) of paneer, with only trace iron. — CoFID 2021 record Cheese, Paneer, code 12-495 (n = 1 record) Evidence E source
  Per 100 g paneer: 328 calories, protein 26.0 g, fat 24.5 g, calcium 537 mg, iron trace, sodium 19 mg
• Raw spinach averages about 1.1 to 1.3 mg iron and 67 to 68 mg calcium per 3.5 oz (100 g), and mature spinach iron ranged from 0.63 to 1.62 mg across eight samples. — USDA FoodData Central Foundation Foods records Spinach, baby and Spinach, mature (n = 8 samples each) Evidence E source
  Iron 1.261 mg (1.02 to 1.6) baby, 1.054 mg (0.63 to 1.62) mature; calcium 68.35 mg and 66.64 mg per 3.5 oz (100 g)

What a real portion looks like

• A cup of palak paneer is set at 200 g in the US survey database, which works out to about 202 calories and 484 mg of sodium. — USDA FNDDS record Palak Paneer, fdc_id 2709631 (n = 1 record) Evidence E source
  1 cup 200 g: 202 calories, sodium 484 mg, calcium 120 mg, iron 1.1 mg; unspecified portion 3.5 oz (100 g)

What your body absorbs

• In a crossover trial on 13 adults, only 5.1% of the calcium in spinach was absorbed against 27.6% from milk at the same 200 mg dose. — 13 healthy adults, randomized crossover, test meals with 200 mg labeled calcium (n = 13) Evidence B source
  Calcium absorption 5.1% from spinach vs 27.6% from milk; within-subject difference 22.5 +/- 9.5 points (P < 0.0001)
• NIH names spinach as an iron source whose iron is poorly absorbed because of inhibitors such as polyphenols. — General population, NIH Office of Dietary Supplements iron fact sheet Evidence E source
  Spinach iron: low bioavailability
• Adding 500 or 1000 mg of calcium to a 270 g spinach meal did not reduce carotenoid absorption in 25 men. — 25 healthy non-obese men aged 20 to 46, randomized double-blind crossover (n = 25) Evidence B source
  No significant change in lutein, beta-carotene or beta-cryptoxanthin AUC with 500 or 1000 mg calcium
• NIH states that only 5% of the calcium in spinach is absorbed against 27% from milk, because oxalic acid binds it. — General population, NIH Office of Dietary Supplements calcium fact sheet Evidence E source
  Calcium absorption 5% from spinach vs 27% from milk

What cooking and storage change

• By the USDA table for Vegetables and Vegetable Products, greens boiled in water to cover and drained keep 60% of folate and 55% of vitamin C, while iron and calcium stay at 95%. — USDA retention factors for the group Vegetables and Vegetable Products, method VEG,GREENS boiled, water cover, drained Evidence E source
  Retained: folate 60%, vitamin C 55%, potassium 85%, iron 95%, calcium 95%
• Pressure-cooked spinach measured 74.85 mg potassium per 3.5 oz (100 g) in a Brazilian cardiology kitchen study, against 253.23 mg when sauteed. — Spinach prepared by different cooking techniques, lab analysis within a crossover trial of 68 heart disease patients Evidence D source
  Potassium per 3.5 oz (100 g): pressure-cooked 74.85 mg, boiled in one water 183.49 mg, sauteed 253.23 mg

What it does to your health

• Across two cohorts of 251,000 adults, moderate nitrate intake from plants, about a cup of baby spinach a day, was linked to 16% lower rates of fatty liver disease (MASLD). — 53,854 Danish Diet, Cancer and Health and 197,198 UK Biobank participants, followed 25.1 and 13.5 years (n = 251052) Evidence C source
  HR Q3 vs Q1 0.84 (95% CI 0.76 to 0.94) for plant-sourced nitrate

Safety, limits and interactions

• Under 2% of the soluble oxalate in grilled spinach was absorbed over 24 hours in 10 volunteers. — 10 volunteers eating 3.5 oz (100 g) grilled spinach alone or with cottage cheese, sour cream, calcium-fortified milk or olive oil (n = 10) Evidence B source
  Soluble oxalate bioavailability 0.75% over 6 h and 1.93% over 24 h; sour cream plus Calci-Trim milk reduced it significantly (P < 0.05)
• A systematic review of warfarin interactions lists spinach among the foods that need attention in people on warfarin. — 149 articles describing 78 herbs, foods or supplements interacting with warfarin (n = 149 articles) Evidence C source
  Spinach named among foods of concern
• Spinach irrigated with untreated wastewater averaged 2.86 mg/kg cadmium in a meta-analysis, more than nine times the EU limit. — 35 studies of wastewater-irrigated soils and crops, 2000 to 2021 (n = 35 studies) Evidence C source
  Spinach pooled mean cadmium 2.86 mg/kg vs EU limit 0.2 to 0.3 mg/kg
• The FDA-approved warfarin label tells patients to keep vitamin K intake consistent rather than cut it, which applies to spinach dishes such as palak paneer. — People taking warfarin Evidence E source
  Advice: consistent vitamin K intake, not avoidance

What people believe that the data does not support

• Eaten together with spinach, milk calcium absorption fell from 33% to 27% in 14 women, a real but partial loss of the dairy calcium. — 14 healthy adult women fed labeled spinach and milk alone and together (n = 14) Evidence B source
  Milk calcium absorption 0.331 alone vs 0.267 with spinach; spinach calcium absorption rose to 0.111
• Oxalic acid itself did not lower iron absorption in 16 women: 10.7% from kale alone vs 11.5% with 1.26 g added oxalate. — 16 healthy women aged 18 to 45, Zurich, two randomized crossover isotope studies, 13 completed both (n = 16) Evidence B source
  Iron absorption 10.7% vs 11.5% (P = 0.86); spinach meal 24% lower than kale meal, not significant (P > 0.16)
• By a meta-analysis of randomized and crossover studies, more calcium lowers short-term iron absorption by about 5.6 percentage points, an effect the authors call low. — Human randomized and crossover studies of calcium intake and iron indices, no age or sex restriction Evidence A source
  Iron absorption WMD -5.57% (95% CI -7.09 to -4.04); hemoglobin WMD +1.22 g/L (0.37 to 2.07)
• The European Union refused a weight-loss claim for a spinach leaf extract, and none of the six spinach-based claims in its register is authorized. — European Union food labeling, claims on spinach-based ingredients Evidence E source
  6 spinach-based claims, 0 authorized; weight reduction claim for spinach extract non-authorized

Who this works differently for

• The body absorbs only 4 to 17% as much vitamin K1 from spinach as from a tablet, and eating the spinach with some fat improves it. — General population, NIH Office of Dietary Supplements vitamin K fact sheet Evidence E source
  Phylloquinone from spinach 4% to 17% of tablet absorption; fat with the meal raises it
• In stably anticoagulated volunteers, vitamin K1 lowered INR from 150 micrograms a day, while spinach and broccoli meals gave only a short-lived response. — Healthy volunteers kept on individual oral anticoagulant doses for 13 weeks Evidence C source
  Threshold 150 ug/day K1 for a significant INR drop, clinically relevant in 25% of participants
• EFSA recommends against feeding spinach to infants and children who have a bacterial gut infection, because they are more sensitive to nitrate. — Infants and young children, EU Evidence E source
  Advice: avoid spinach during bacterial gastrointestinal infection
• An 8-year-old boy fed blended meals heavy in spinach and nuts developed oxalate kidney damage, with creatinine still rising after the diet changed. — One 8-year-old boy dependent on pureed feeds (n = 1) Evidence D source
  Kidney biopsy with extensive oxalate crystals; serum creatinine 1.8 then 2.1 mg/dL

The bottom line

Oxalate gets the blame for spinach iron, and in 16 Swiss women it did not earn it. Adding 1.26 g of oxalic acid to a kale meal left iron absorption at 11.5 percent against 10.7 percent without it. A spinach meal in the same study came out 24 percent lower than kale, a gap that did not reach significance. The pairing costs the dairy a little. In 14 women, milk calcium absorption fell from 33 to 27 percent when spinach was eaten with it, in single meals with milk rather than paneer, so the exact loss in the dish is unmeasured. The NIH calcium fact sheet repeats the 5 against 27 percent figure for spinach and milk, and it rests on the same 1988 trial. Calcium did not blunt the spinach carotenoids: 500 or 1000 mg of calcium with a 270 g spinach meal left lutein and beta-carotene absorption unchanged in 25 men. Blanching and pureeing the spinach costs the water-soluble vitamins. By the USDA group factor for greens boiled and drained, 60 percent of folate and 55 percent of vitamin C remain while iron and calcium stay at 95 percent, and that factor was never measured on palak itself. For people on potassium limits, a Brazilian kitchen analysis measured 75 mg of potassium per 3.5 oz (100 g) in pressure-cooked spinach against 253 mg when sauteed, a lab measurement of the food with no outcome in people. The liver finding is observational. Across 251,052 adults in two cohorts, moderate plant nitrate intake, about a cup of baby spinach a day, went with 16 percent lower rates of fatty liver disease (HR 0.84, 95% CI 0.76 to 0.94), with nitrate counted from all plants. The EU refused a weight-loss claim for a standardized spinach leaf extract, a product made from spinach that is not the leaf in this dish. Who should be careful. Paneer is a fresh cheese and the dish is usually finished with cream or ghee, so it is not for anyone who must avoid milk. In healthy volunteers kept on warfarin-type anticoagulants, vitamin K1 lowered INR from 150 micrograms a day, while spinach meals gave only a short-lived response. A systematic review built mostly on case reports lists spinach among the foods to watch on warfarin. The body absorbs 4 to 17 percent as much vitamin K1 from spinach as from a tablet, and fat in the meal, such as ghee or cream, raises that. The FDA-approved warfarin label asks patients to keep their vitamin K intake consistent, and it names vitamin K in food without naming spinach. The person managing your dose should know you eat the dish. For people who form kidney stones the one measurement here is small and was not made in stone formers: in 10 volunteers, under 2 percent of the soluble oxalate in 3.5 oz (100 g) of grilled spinach was absorbed over 24 hours, and dairy eaten alongside cut it further. It does not say how much oxalate a portion of the dish carries, so it is no clearance for people told to limit oxalate. The ceiling case is one 8-year-old boy on pureed feeds heavy in spinach and nuts every day, who developed oxalate kidney damage. EFSA advises against spinach for infants and young children with a bacterial gut infection, because they are more sensitive to nitrate. Spinach grown with untreated wastewater averaged 2.86 mg/kg cadmium in a meta-analysis, over nine times the EU limit, while properly treated water gave control-level cadmium.

Sources

1. palp-local-r4-01 · USDA FNDDS, dataset
   Palak Paneer (FNDDS, fdc_id 2709631): Energy 101 KCAL, Calcium, Ca 60 MG, Iron, Fe 0.55 MG, Sodium, Na 242 MG per 100 g
   USDA FNDDS, Palak Paneer, FDC 2709631 · checked 2026-09-28
2. palp-local-r4-03 · CoFID 2021, dataset
   Cheese, Paneer (CoFID 2021, code 12-495): Energy 328 kcal, Protein 26.0 g, Fat 24.5 g, Calcium 537 mg, Iron Tr, Sodium 19 mg per 100 g
   CoFID 2021 (Public Health England), Cheese, Paneer, 12-495 · checked 2026-09-28
3. palp-local-r4-04 · USDA FoodData Central Foundation Foods, dataset
   Spinach, baby: Iron, Fe 1.261 MG, range 1.02-1.6, 8 samples; Calcium, Ca 68.35 MG, range 48.2-92.1; Spinach, mature: Iron, Fe 1.054 MG, range 0.63-1.62, 8 samples; Calcium, Ca 66.64 MG, range 47.3-89.2 (FDC Foundation Foods, release 2026-04-30)
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-28
4. palp-local-r4-02 · USDA FNDDS portion weights, dataset
   Palak Paneer (FNDDS, fdc_id 2709631): 1 cup 200 g: Energy 202.0 KCAL, Sodium, Na 484.0 MG, Calcium, Ca 120.0 MG, Iron, Fe 1.1 MG; Quantity not specified 100 g
   USDA FNDDS, Palak Paneer, FDC 2709631 · checked 2026-09-28
5. palp-local-r4-05 · RCT
   Absorption was higher from milk in every case, with the mean absorption from milk averaging 27.6% and from spinach, 5.1%.
   Am J Clin Nutr, 1988 · checked 2026-09-28
6. palp-local-r4-10 · fact sheet
   Some plant-based foods that are good sources of iron, such as spinach, have low iron bioavailability because they contain iron-absorption inhibitors, such as polyphenols [23,24].
   NIH Office of Dietary Supplements, Iron fact sheet for health professionals · checked 2026-09-28
7. palp-local-r4-12 · RCT
   No significant influence of supplementation with either 500 or 1000 mg of supplemental Ca was found.
   Br J Nutr, 2017 · checked 2026-09-28
8. palp-local-r4-21 · fact sheet
   As a result, absorption of calcium is only 5% for spinach, whereas it is much higher, at 27%, for milk [3].
   NIH Office of Dietary Supplements, Calcium fact sheet for health professionals · checked 2026-09-28
9. palp-local-r4-13 · USDA Table of Nutrient Retention Factors, Release 6, dataset
   USDA-RETN-R6:3005 VEG,GREENS,BOILED,WATER COVER DRAIN: vitamin_c_mg 55%, folate_total_ug 60%, potassium_mg 85%, calcium_mg 95%, iron_mg 95%
   USDA Table of Nutrient Retention Factors, Release 6 (2007) · checked 2026-09-28
10. palp-local-r4-14 · food analysis
    The vegetables with the lowest potassium values were spinach (74.85 mg/100 g) and zucchini (93.62 mg/100 g), both cooked under pressure.
    Clin Nutr ESPEN, 2025 · checked 2026-09-28
11. palp-local-r4-20 · cohort
    moderate plant-sourced intakes (∼1 cup baby spinach/day) were linked to lower MASLD rates
    Clin Nutr, 2026 · checked 2026-09-28
12. palp-local-r4-07 · RCT
    The mean bioavailability of soluble oxalate in the grilled spinach was 0.75+/-0.48% over a 6-hour period after intake and was 1.93+/-0.85% measured over a 24-hour period.
    Asia Pac J Clin Nutr, 2003 · checked 2026-09-28
13. palp-local-r4-16 · systematic review
    These include Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John's Wort, sushi and smoking tobacco.
    Br J Clin Pharmacol, 2021 · checked 2026-09-28
14. palp-local-r4-19 · meta-analysis of observational data
    spinach (pooled mean 2.86 mg/kg) exceeding the EU safety limit (0.2-0.3 mg/kg) by factors of > 130, > 77, and > 9.5, respectively
    Environ Monit Assess, 2026 · checked 2026-09-28
15. palp-local-r4-22 · drug label
    The amount of vitamin K in food may affect therapy with warfarin sodium. Advise patients taking warfarin sodium to eat a normal, balanced diet maintaining a consistent amount of vitamin K.
    Warfarin sodium, FDA-approved label (DailyMed), effective 2026-06-25 · checked 2026-09-28
16. palp-local-r4-06 · RCT
    In the same 14 women, milk absorption averaged 0.331 +/- 0.092 when ingested alone. However, when co-ingested with spinach, apparent milk calcium absorption fell to 0.267 +/- 0.079 and apparent spinach calcium absorption rose to 0.111 +/- 0.039.
    Calcif Tissue Int, 1991 · checked 2026-09-28
17. palp-local-r4-08 · RCT
    geometric mean iron absorption from wheat bread rolls with kale (10.7%) did not differ significantly from wheat rolls with kale plus 1.26 g OA added as potassium oxalate (11.5%, P=0.86)
    Eur J Clin Nutr, 2008 · checked 2026-09-28
18. palp-local-r4-09 · meta-analysis
    The negative effect of calcium intake was statistically significant in short-term iron absorption studies, but the effect magnitude was low [weighted mean difference (WMD) = -5.57%; 95% CI: -7.09 to -4.04].
    J Nutr, 2021 · checked 2026-09-28
19. palp-local-r4-23 · regulatory register entry
    POL-HC-12721 Appethyl®, an aqueous extract from spinach leaves standardised by the manufacturing process and its lipase/colipase inhibition capacity in vitro Appethyl® helps your body weight reduction during mild caloric restriction Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-12721, snapshot 2026-09-21 · checked 2026-09-28
20. palp-local-r4-11 · fact sheet
    For example, the body absorbs only 4% to 17% as much phylloquinone from spinach as from a tablet [2]. Consuming vegetables at the same time as some fat improves phylloquinone absorption from the vegetables, but the amount absorbed is still lower than that from oils.
    NIH Office of Dietary Supplements, Vitamin K fact sheet for health professionals · checked 2026-09-28
21. palp-local-r4-15 · clinical trial
    The threshold K(1) dose causing a statistically significant lowering of the INR was 150 microg/day.
    Blood, 2004 · checked 2026-09-28
22. palp-local-r4-17 · EFSA CONTAM Panel statement
    The CONTAM Panel noted that infants and children with bacterial infections of the gastrointestinal tract are more sensitive to nitrate, and recommended against feeding spinach to such children.
    EFSA Journal, 2010 · checked 2026-09-28
23. palp-local-r4-18 · case report
    The patient depended on pureed foods for nutrition, and his mother consistently used a large amount of spinach and nuts when preparing his blenderized feeds.
    Kidney Med, 2025 · checked 2026-09-28