NutriDex

The Supplement Research Compendium
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Kiwifruit

Actinidia deliciosa

Vitamin C-dense fruit that eases constipation

Moderate evidence 🍎Fruits

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
9 verified / 9
Classification
Fruits
❝
What the evidence says. Several controlled trials; effects real but modest or context-dependent.

Nutrition per serving 1 medium (69 g)

69gSERVING
  • Water 57.3 g84%
  • Sugars 6.2 g9%
  • Fibre 2.1 g3%
  • Other carbs 1.8 g3%
  • Protein 0.8 g1%
  • Fat 0.4 g1%
What's in one serving, by weight — average composition (USDA).
Vitamin C71%Vitamin K23%Fibre8%Copper10%Vitamin E7%Potassium5%Folate4%
One serving as % of the adult daily requirement (FDA Daily Values). The bold outer ring = 100% of a day's needs.
42 kcal0.79 g protein2.1 g fiber0.36 g fat
NutrientPer serving% daily value
Vitamin C64 mg71%
Vitamin K28 mcg23%
Fibre2.1 g8%
Copper0.09 mg10%
Vitamin E1 mg7%
Potassium215 mg5%
Folate17 mcg4%
Magnesium12 mg3%
Calcium23 mg2%

Composition data: USDA FoodData Central ↗

What is Kiwifruit?

Kiwifruit (Actinidia deliciosa) is a fruit used for relieves functional constipation and improves bowel regularity. NutriDex grades the human evidence as Moderate. Kiwifruit is one of the most vitamin C-dense common fruits, and even small daily portions reliably raise plasma ascorbate. The best-supported clinical benefit is for functional constipation: multiple RCTs and a systematic review/meta-analysis show two kiwifruit daily increase spontaneous bowel movements and reduce abdominal discomfort, with efficacy comparable to fibre-matched psyllium, attributed to its fibre, water and the enzyme actinidin. The meta-analysis rated certainty as low, reflecting small samples and risk of bias. A randomised trial found three kiwifruit daily modestly lowered 24-hour blood pressure versus an apple, and small crossover trials suggest possible mood or sleep benefits, but these findings are preliminary (often only trend-level) and need replication. Overall, the human evidence is most convincing for laxation and vitamin C status, while broader cardiometabolic and sleep claims remain exploratory.

Purported Benefits

✓Relieves functional constipation and improves bowel regularity
✓Raises plasma vitamin C and supports antioxidant status
✓May modestly lower 24-hour blood pressure
✓Improves laxation with efficacy comparable to psyllium
✓Preliminary, trend-level evidence for improved sleep or mood
✓Provides vitamin K and vitamin E with low glycaemic load

Dosing & Compounds

Typical Dose
Two green kiwifruit daily (about 140-180 g) is the dose used in most constipation trials; one medium kiwi (~69 g) supplies roughly 70% of the adult vitamin C Daily Value. Eat the whole edible flesh, ideally with skin for extra fibre.
Active Compounds
Vitamin C (ascorbic acid)Dietary fibre (soluble and insoluble)Actinidin (proteolytic enzyme)Vitamin K1 (phylloquinone)Vitamin E (alpha-tocopherol)PotassiumPolyphenols (flavonoids, chlorogenic acid)Lutein and zeaxanthin (carotenoids)Folate

Safety & Cautions

Kiwifruit is a recognised allergen and can cause oral allergy syndrome or, rarely, anaphylaxis, often cross-reacting with latex, birch pollen, avocado and banana. It is high in oxalate, so people prone to calcium-oxalate kidney stones should moderate intake. The vitamin K content can slightly affect warfarin dosing if intake changes abruptly. The actinidin enzyme can intensify reactions in sensitised individuals. It carries a meaningful natural sugar load; portion accordingly in diabetes. No clinically important grapefruit-type CYP3A4 interaction is known. Educational only — always check with your doctor or pharmacist before combining Kiwifruit with any medicine.

Key Studies

Systematic review Bayer 2023 (Ann Intern Med synopsis) ✓ PubMed
Annals of Internal Medicine evidence synopsis of the Gearry trial concluded that in persons with constipation or IBS-C, kiwifruit versus psyllium increased spontaneous bowel movements.
Meta-analysis Eltorki 2022 ✓ PubMed
Systematic review/meta-analysis of 7 RCTs (399 participants): kiwifruit increases weekly spontaneous bowel movements vs placebo or psyllium and reduces abdominal pain, with low certainty of evidence.
Agency / regulator UKNHCC 2024 ✓ Source
UK Nutrition and Health Claims Committee scientific opinion assessed the evidence for green kiwifruit powder and maintenance of normal defecation.
RCT Gearry 2023 ✓ PubMed
International multicentre crossover RCT (184 adults): two green kiwifruit daily clinically improved constipation (>=1.5 more complete spontaneous bowel movements/week) and abdominal comfort.
RCT Kanon 2023 ✓ PubMed
Single-blind crossover study in 24 men: fresh or dried green kiwifruit with an evening meal produced only modest, trend-level improvements in mood/sleep measures and raised the serotonin metabolite 5-HIAA.
RCT Bayer 2022 ✓ PubMed
Crossover RCT (56 adults, including functional constipation and IBS-C): two gold kiwifruit daily as effective as fibre-matched psyllium for treating constipation, with less straining.
RCT Conner 2020 ✓ PubMed
Placebo-controlled trial (167 adults with low vitamin C status): two SunGold kiwifruit daily raised plasma vitamin C to saturation within two weeks and improved subjective vitality (fatigue, well-being).
RCT Svendsen 2015 ✓ PubMed
RCT in 118 adults with moderately elevated BP: three kiwifruit/day lowered 24-hour systolic and diastolic blood pressure versus one apple/day over 8 weeks.
Review Rick 2026 ✓ PubMed
Allergens from plant-based food allergen sources and their clinical and diagnostic relevance
9 sources cited · 9 verified Search all studies on PubMed ↗

Common questions about Kiwifruit

What is Kiwifruit used for?

Kiwifruit is most often taken for Relieves functional constipation and improves bowel regularity, Raises plasma vitamin C and supports antioxidant status, May modestly lower 24-hour blood pressure, Improves laxation with efficacy comparable to psyllium. Vitamin C-dense fruit that eases constipation

Does Kiwifruit work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. Kiwifruit is one of the most vitamin C-dense common fruits, and even small daily portions reliably raise plasma ascorbate. The best-supported clinical benefit is for functional constipation: multiple RCTs and a systematic review/meta-analysis show two kiwifruit daily increase spontaneous bowel movements and reduce abdominal discomfort, with efficacy comparable to fibre-matched psyllium, attributed to its fibre, water and the enzyme actinidin. The meta-analysis rated certainty as low, reflecting small samples and risk of bias. A randomised trial found three kiwifruit daily modestly lowered 24-hour blood pressure versus an apple, and small crossover trials suggest possible mood or sleep benefits, but these findings are preliminary (often only trend-level) and need replication. Overall, the human evidence is most convincing for laxation and vitamin C status, while broader cardiometabolic and sleep claims remain exploratory.

What is the typical dose of Kiwifruit?

Two green kiwifruit daily (about 140-180 g) is the dose used in most constipation trials; one medium kiwi (~69 g) supplies roughly 70% of the adult vitamin C Daily Value. Eat the whole edible flesh, ideally with skin for extra fibre.

Is Kiwifruit safe? Any cautions or side effects?

Kiwifruit is a recognised allergen and can cause oral allergy syndrome or, rarely, anaphylaxis, often cross-reacting with latex, birch pollen, avocado and banana. It is high in oxalate, so people prone to calcium-oxalate kidney stones should moderate intake. The vitamin K content can slightly affect warfarin dosing if intake changes abruptly. The actinidin enzyme can intensify reactions in sensitised individuals. It carries a meaningful natural sugar load; portion accordingly in diabetes. No clinically important grapefruit-type CYP3A4 interaction is known.

How many studies support Kiwifruit?

NutriDex cites 9 sources for Kiwifruit, graded "Moderate".

Cite this page
APA

Peh, D. (2026). Kiwifruit (Actinidia deliciosa): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 10 Aug 2026, from https://nutridex.info/s/kiwifruit

BibTeX
@misc{nutridex_kiwifruit,
  author       = {Peh, Daryl},
  title        = {Kiwifruit (Actinidia deliciosa): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/kiwifruit},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-08-10}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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