Cucumber vs zucchini: calories compared

Nutritionally, one can stand in for the other. Both are about 95% water in USDA samples. Zucchini has more potassium, 261 mg against 170 mg per 3.5 oz (100 g) in the table, and adds about 15 mg of vitamin C. Cucumber's standout is vitamin K. A whole 7 oz (200 g) cucumber holds 48 mcg, 40% of the Daily Value.

Two groups should read on. If you take warfarin or a similar anticoagulant, NIH advises keeping vitamin K intake steady, so a sudden cucumber habit is worth noticing. If you have kidney disease or take ACE inhibitors or potassium-sparing diuretics, NIH says even intakes below the adequate amount can push blood potassium too high, and advises asking a doctor or dietitian. Cooking lowers it. In UK tables, boiling cut zucchini potassium from 341 to 238 mg, and pressure-cooked zucchini measured about 94 mg in a Brazilian study.

A squash that tastes bitter goes in the bin. French poison centers recorded 353 people exposed to bitter squash, 57.8% had symptoms and none died. A 66-year-old woman in Germany was taken to the emergency department after eating a bitter zucchini. A UK outbreak of E. coli O157 in 36 people was likely caused by a product whose only specific ingredient was cucumber.

Use cucumber raw and zucchini cooked, and trust your taste buds.

Evidence behind this note

1. Level E Per 100 g raw, zucchini held 225.8 mg potassium, 15 mg vitamin C and 71 mcg folate against 169.6 mg potassium in cucumber, both about 95% water. USDA FoodData Central, Foundation Foods, release 2026-04-30
2. Level E A whole cucumber carries about two fifths of a day's vitamin K, which matters to one group of readers and to nobody else. USDA FNDDS 2021-2023, Cucumber, raw (fdc_id 2709784)
3. Level E NIH names broccoli among the most common US sources of vitamin K and advises people on warfarin to keep their vitamin K intake consistent, since sudden changes can raise or lower the drug's effect. NIH Office of Dietary Supplements, Vitamin K Fact Sheet for Health Professionals
4. Level D A 66-year-old woman was hospitalized with tachycardia, hypotension, diarrhea and hemorrhagic colitis after eating bitter zucchini, and the bitter taste was what pointed to cucurbitacin poisoning. Dtsch Med Wochenschr, 2020
5. Level C Among 353 people reported to French poison centers after eating bitter, non-edible squash in 2012 to 2016, 57.8% had symptoms, mostly diarrhea, vomiting and abdominal pain. 4.0% were moderately ill and none died. The authors advise throwing away any squash that tastes bitter. Clin Toxicol (Phila), 2018
6. Level E The NIH Office of Dietary Supplements says high dietary potassium is no risk for healthy people with normal kidneys, but in chronic kidney disease or on drugs such as ACE inhibitors or potassium-sparing diuretics even intakes below the adequate intake can cause hyperkalemia. NIH Office of Dietary Supplements, Potassium Health Professional Fact Sheet
7. Level E Boiling zucchini dropped its potassium from 341 to 238 mg and vitamin C from 5 to 1 mg per 3.5 oz (100 g) in the UK tables. CoFID 2021, Public Health England, records 13-627 and 13-628
8. Level B Pressure cooked zucchini held 93.62 mg potassium per 3.5 oz (100 g), the second lowest value among the vegetables measured in a randomized crossover trial run with 68 cardiology patients. Clin Nutr ESPEN, 2025
9. Level C Observational data tie a UK outbreak of E. coli O157 in 36 people to a fast-food product whose only specific ingredient was imported cucumber. Int J Infect Dis, 2021

Written from the studies and agency guidance we hold for both foods, reviewed by the Bioma editorial system. How we verify.

Read more about these foods

• Cucumber vs zucchini: mostly water, with more potassium in zucchini
• Cucumber: water, vitamin K, and one trial about a capsule
• Zucchini: the pan sets the potassium, and bitter means bin it

Rankings and guides

• Calories: what it does and what the evidence shows
• Which foods give the most protein for the fewest calories?
• Dietary fat: what it does and how much you need
• Zucchini: full nutrition facts

More comparisons

• Cucumber vs pickles

• Cucumber: USDA FoodData Central, Cucumber, with peel, raw, FDC ID 2346406 · all forms of cucumber
• Zucchini: USDA FoodData Central, Squash, summer, zucchini, includes skin, raw, FDC ID 169291 · full profile · all forms of zucchini

Each food is one USDA entry, chosen as it is usually eaten. Other cuts, brands and preparations differ; the links show them. % DV uses FDA Daily Values for adults. How we verify.