Butternut squash: plenty of carotene, very little research

The one trial close to butternut squash used sweet pumpkin. In 110 dewormed Bangladeshi schoolchildren fed a meal six days a week for 6 weeks, serum beta-carotene rose in every group, including the one getting 1.5 mg a day from pumpkin, where 18 of 36 children dropped out. Only dark leafy greens clearly beat the control, with a rise of 0.44 against 0.20 umol/l. We found no randomized trial of butternut squash itself on any health outcome. What it reliably has is carotene. UK tables list 3630 ug per 3.5 oz (100 g) raw. A 225 g cup of cooked winter squash, a generic entry rather than butternut alone, gives about 6.3 mg of beta-carotene, or 585 ug of vitamin A activity, in the US survey database. Vitamin C is where the sources part ways. USDA measured 7.6 mg per 3.5 oz (100 g) raw, with 8 samples between 4.9 and 13.8 mg, and UK tables say 21 mg.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• Raw butternut squash has about 329 mg potassium and 55 ug folate per 3.5 oz (100 g) in USDA samples, each varying roughly twofold between samples. — Not applicable (food composition) (n = 8) Evidence E source
  Potassium 329 mg (214 to 492); folate 55 ug (26 to 78) per 3.5 oz (100 g)
• UK food tables list raw butternut squash at 3630 ug carotene, 21 mg vitamin C and 36 calories per 3.5 oz (100 g). — Not applicable (food composition) Evidence E source
  Per 100 g: carotene 3630 ug, retinol equivalent 605 ug, vitamin C 21 mg, potassium 350 mg, 36 calories

What a real portion looks like

• One cup (225 g) of cooked winter squash supplies about 6.3 mg beta-carotene, or 585 ug vitamin A activity, in the US survey database. — Not applicable (food composition) Evidence E source
  Per 100 g: beta-carotene 2785 ug, vitamin A 260 ug RAE; 1 cup 225 g: 6266 ug and 585 ug RAE
• Ugandan infants aged 6 to 24 months ate about 1.9 oz (54 g) of a 100 g pumpkin-based complementary food, giving about 153 ug vitamin A RAE per serving. — Children 6 to 24 months, 70, crossover acceptability test (n = 70) Evidence B source
  Mean intake 54.4 g; vitamin A 152.5 ug RAE (pumpkin blend) vs 100.9 ug (bean-pumpkin)

What your body absorbs

• In 110 dewormed Bangladeshi schoolchildren fed daily meals for 6 weeks, serum beta-carotene rose in all groups, including 1.5 mg from sweet pumpkin, but only leafy greens beat the control clearly. — Children aged 8 to 12 years, 110, one meal 6 days a week for 6 weeks (n = 110) Evidence B source
  Serum beta-carotene rise 0.44 umol/l with leafy greens vs 0.20 in control (P = 0.002); pumpkin group vs control not reported as different
• Eating 6.3 oz (180 g) a day of green beans, pumpkin and sweet corn for 4 weeks raised serum lutein by about 37% in middle aged adults. — Healthy normolipemic adults aged 45 to 65, 29, four weeks (n = 29) Evidence C source
  Serum lutein up 37%; macular pigment unchanged

What cooking and storage change

• In UK food tables, boiled butternut squash lists far less carotene (452 vs 3630 ug), vitamin C (1 vs 21 mg) and potassium (147 vs 350 mg) per 3.5 oz (100 g) than raw. — Not applicable (food composition) Evidence E source
  Boiled vs raw per 3.5 oz (100 g): carotene 452 vs 3630 ug; vitamin C 1 vs 21 mg; potassium 147 vs 350 mg
• Baked butternut squash in UK tables has 744 ug carotene and 8.4 g sugars per 3.5 oz (100 g), with vitamin C near 1 mg. — Not applicable (food composition) Evidence E source
  Per 100 g baked: carotene 744 ug, sugars 8.4 g, vitamin C 1 mg, 39 calories
• USDA retention factors for vegetables keep about 85% of vitamin C when baked and 75% when boiled in water and drained. — Not applicable (food composition) Evidence E source
  Vitamin C retained: baked 85%, boiled and drained 75%; folate 85% and 65%

What it does to your health

• In 177,148 UK Biobank adults, those who liked butternut squash had 25% lower all-cause mortality over 3.4 years, a preference link that does not prove the food itself protects. — UK Biobank participants, 177,148, mean follow-up 3.4 years (n = 177148) Evidence C source
  HR 0.75 (95% CI 0.68 to 0.83) for high vs low preference

Safety, limits and interactions

• An 11 year old girl with a developmental disorder suffered an esophageal thermal burn after swallowing a piece of hot butternut squash. — One child aged 11 with macrocephaly capillary malformation syndrome (n = 1) Evidence D source
  Linear white plaques from thermal burns on endoscopy
• Handling raw butternut squash can cause dry, flaking hand dermatitis, which a case report calls uncommon but probably under-reported. — One man aged 28 after handling butternut squash (n = 1) Evidence D source
  Dry and flaking skin of palm and fingers

What is still unknown

• USDA measured 7.6 mg vitamin C per 3.5 oz (100 g) of raw butternut squash, but 8 samples ranged from 4.9 to 13.8 mg. — Not applicable (food composition) (n = 8) Evidence E source
  Vitamin C 7.6 mg/100 g, range 4.9 to 13.8 (median 7.0)

The bottom line

On paper, cooking changes the numbers a lot. UK tables list boiled butternut at 452 ug carotene, 1 mg vitamin C and 147 mg potassium per 3.5 oz (100 g), against 3630 ug, 21 mg and 350 mg raw. The two entries may come from different samples, and part of the drop is water taken up in the pot. Baked butternut lists 744 ug carotene, 8.4 g sugars and about 1 mg vitamin C per 3.5 oz (100 g). The general USDA factors for vegetables keep about 85% of vitamin C when baked and 75% when boiled and drained, group figures from 1975 never measured on this squash. The UK and US pictures do not agree. Raw squash in the USDA samples also has about 329 mg potassium and 55 ug folate per 3.5 oz (100 g), each varying about twofold across the 8 samples. The other feeding studies used pumpkin in a mix. In 29 adults aged 45 to 65, 180 g a day of green beans, pumpkin and sweet corn for four weeks raised serum lutein by 37%, in a non-randomized trial where pumpkin cannot be separated from the other two. Ugandan infants aged 6 to 24 months ate about 1.9 oz (54 g) of a 100 g pumpkin-based complementary food, which gave them about 153 ug vitamin A RAE per serving. Among 177,148 UK Biobank adults, people who said they liked butternut squash had 25% lower all-cause mortality over 3.4 years (hazard ratio 0.75, 95% CI 0.68 to 0.83). The study measured taste rather than intake, over a short follow-up, and overall lifestyle may explain much of it. Liking asparagus, broccoli or black pepper came with similar numbers. The cautions we have are two single cases. A 28 year old man developed dry, flaking skin on his palm and fingers after handling raw butternut squash, which the report calls uncommon but possibly under-reported. An 11 year old girl with a developmental disorder burned her esophagus swallowing a piece of hot squash, a hazard of heat that any hot food carries. We found no data on pregnancy, older adults, kidney disease or drug interactions.

Sources

1. bnsr8-02 · dataset
   Squash, winter, butternut, raw (FDC 2685570, foundation): Potassium, K 329.1 mg (range 214.0–492.0); Folate, total 55.0 µg (range 26.0–78.0) per 100 g, 8 samples
   USDA FoodData Central, Foundation Foods 2026-04-30, FDC 2685570 Squash, winter, butternut, raw · checked 2026-09-29
2. bnsr8-03 · dataset
   Squash, butternut, raw (CoFID 13-355): Carotene 3630 µg; Retinol Equivalent 605 µg; Vitamin C 21 mg; Potassium 350 mg; Energy 36 kcal per 100 g
   CoFID 2021 (Public Health England), code 13-355 Squash, butternut, raw · checked 2026-09-29
3. bnsr8-07 · dataset
   FNDDS 2709694 Winter squash, cooked, no added fat: Carotene, beta 2785 µg/100 g · 1 cup 225 g 6266.2 µg; Vitamin A, RAE 260 µg/100 g · 1 cup 225 g 585.0 µg
   USDA FNDDS (WWEIA 2021-2023), fdc_id 2709694 Winter squash, cooked, no added fat · checked 2026-09-29
4. bnsr8-10 · RCT
   The mean consumption of BPB and PB was 53.9 g and 54.4 g, respectively. ... The mean intake of vitamin A was significantly higher (p < 0.00001) in PB (152.5 μgRAE) compared to BPB (100.9 μgRAE).
   BMC Pediatr, 2020 · checked 2026-09-29
5. bnsr8-08 · RCT
   (2) 1.5 mg beta-carotene from sweet pumpkin (n=36, 18 dropouts); ... Significant increases (P < 0.001) in mean serum beta-carotene concentrations were seen in all three study groups, with a statistically higher increase (micromol/l) in the DGLV group (0.44; 95% confidence interval (CI) 0.32, 0.55) compared to the control group (0.20; 95% CI 0.14, 0.26; P = 0.002).
   Eur J Clin Nutr, 2001 · checked 2026-09-29
6. bnsr8-09 · clinical trial
   Twenty-nine healthy normolipemic subjects, aged 45-65 y, consumed 1.8 mg lutein/day supplied from fruits (14 subjects, 500 g/day of oranges, kiwi and avocados) or vegetables (15 subjects, 180 g/day of green beans, pumpkin, and sweet corn) for four weeks. Serum lutein concentration increased by 37%.
   Nutrients, 2021 · checked 2026-09-29
7. bnsr8-04 · dataset
   Squash, butternut, boiled in unsalted water (CoFID 13-643): Carotene 452 µg; Vitamin C 1 mg; Potassium 147 mg; Energy 24 kcal per 100 g
   CoFID 2021 (Public Health England), code 13-643 Squash, butternut, boiled in unsalted water · checked 2026-09-29
8. bnsr8-05 · dataset
   Squash, butternut, baked (CoFID 13-644): Carotene 744 µg; Total sugars 8.4 g; Vitamin C 1 mg; Energy 39 kcal per 100 g
   CoFID 2021 (Public Health England), code 13-644 Squash, butternut, baked · checked 2026-09-29
9. bnsr8-06 · dataset
   USDA-RETN-R6:3771 VEG,OTHER,BAKED: vitamin_c_mg 85%; folate_total_ug 85% · USDA-RETN-R6:3775 VEG,OTHER,BLD,WATER COVER,DRAINED: vitamin_c_mg 75%; folate_total_ug 65%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), Retn_Code 3771 and 3775 · checked 2026-09-29
10. bnsr8-11 · prospective cohort
    Higher preference for asparagus (hazard ratio (95% confidence interval)): 0.69 (0.62, 0.77)), aubergine (0.79 (0.72, 0.87)), black pepper (0.72 (0.64, 0.81)), broccoli (0.69 (0.61, 0.79)), butternut squash (0.75 (0.68, 0.83)), and extra virgin olive oil (0.67 (0.58, 0.78)) was linked to lower all-cause mortality
    Sci Rep, 2026 · checked 2026-09-29
11. bnsr8-12 · case report
    We present the case of an 11-year-old female with macrocephaly capillary malformation syndrome and developmental delay suffering from ETI after ingestion of a piece of hot butternut squash.
    JPGN Rep, 2023 · checked 2026-09-29
12. bnsr8-13 · case report
    appears to be an uncommon phenomenon, but it may occur more often and not be reported
    Case Reports in Dermatology, 2022 · checked 2026-09-29
13. bnsr8-01 · dataset
    Squash, winter, butternut, raw (FDC 2685570, foundation): Vitamin C, total ascorbic acid 7.6 mg per 100 g; range 4.9–13.8 (median 7.0), 8 samples
    USDA FoodData Central, Foundation Foods 2026-04-30, FDC 2685570 Squash, winter, butternut, raw · checked 2026-09-29