The vitamin C truth, and which berries deliver
Every chart tells you how much vitamin C a food contains. Almost none of them tell you how much is still there by the time you eat it. Here is what the vitamin does, what storage and heat quietly take back, and which berries genuinely carry the most.
Every figure below is linked to a published source. Ranges are printed as ranges rather than averaged into a single tidy number, because the range is the honest part. Product figures come from the published nutrition label.
The short answer
Vitamin C builds collagen, donates electrons as an antioxidant, and concentrates in white blood cells. It is also the least stable nutrient in fruit. Salad leaves lost an average of 59 percent of it over ten days in a fridge. Acerola and sea buckthorn carry the most per 100 g. Blueberries carry the least.
In this article
What vitamin C actually does
Most people know vitamin C as the thing you take when you feel a cold coming. That is the smallest and least interesting part of the story. The vitamin has a specific structural job in the body, and once you know what it is, the rest of the article follows from it.
It builds collagen. Vitamin C is a cofactor for the lysyl and prolyl hydroxylases that stabilise the tertiary structure of collagen.1 Collagen is the scaffolding protein of skin, tendon, cartilage, bone and blood vessel wall. Without vitamin C, those hydroxylase enzymes cannot finish the job, and the collagen that gets made is structurally weaker. This is not a wellness metaphor. It is the reason scurvy looks the way it does: bleeding gums, poor wound healing, fragile vessels. Every one of those is a collagen failure.
It donates electrons. Vitamin C is described as a highly effective antioxidant because it readily donates electrons, which is how it protects other molecules from oxidative damage.1 That same eagerness to give up electrons is exactly why the vitamin is so fragile in food. A molecule that oxidises easily inside you also oxidises easily in a bag of spinach. Hold onto that thought, because the next section is built on it.
It concentrates in white blood cells. Vitamin C accumulates in phagocytic cells such as neutrophils, where it has been shown to enhance chemotaxis and phagocytosis, and it supports the barrier function of epithelial tissue. Research also reports it enhancing the differentiation and proliferation of B cells and T cells.1 That is a description of normal physiology, not a promise about outcomes.
Three jobs, one molecule, and a chemistry that makes it unusually easy to lose. Which brings us to the part almost nobody prints on a chart.
The number on the chart is not the number that reaches you
A nutrition table gives you a figure measured at one moment, usually on fresh produce at or near harvest, in a laboratory. What arrives in your kitchen has been picked, washed, chilled, boxed, trucked, shelved, bought, carried, refrigerated again, and often cooked. Vitamin C is measurably lower at the end of that chain than at the start, and the size of the gap surprises most people.
A 2017 study followed ascorbate in salad leaves through commercial washing and post-harvest storage. Every leaf type tested showed a significant decrease over ten days at 4 degrees Celsius in darkness. The mean loss across varieties was 59 percent, and baby iceberg lettuce lost 86 percent.2 That is a bag of leaves in a normal fridge, in the dark, at the correct temperature, doing nothing wrong. More than half the vitamin C is simply gone.
A separate 2017 study stored nineteen fruits and vegetables at 4 degrees Celsius and measured vitamin C by three different methods. By the AOAC method, tomato lost 71.8 percent after fourteen days.3 The authors are careful to note that the three assay methods disagree with each other, which is itself worth knowing: part of the variation you see between published vitamin C figures is methodology, not biology.
Figure 01
How much vitamin C leaves food before you eat it
Percentage of vitamin C lost in published studies. Every one of these is a normal thing that happens to normal food.
Storage figures from Dewhirst and colleagues, Food Chemistry, 2017 and Galani and colleagues, Antioxidants, 2017. Cooking figures from Razzak and colleagues, Heliyon, 2023. Different foods, different studies, shown together to give the scale of the effect rather than to compare foods with each other.
A 2007 review of fresh, frozen and canned produce put it plainly: loss of nutrients in fresh products during storage and cooking may be more substantial than commonly perceived.4 The same review notes that canning costs vitamin C up front through heat, but that what survives is then relatively stable in the can, because there is no oxygen in there. Frozen and canned are not automatically the poor relations of fresh. Sometimes they are the opposite.
A nutrition chart is a photograph of a food at its best moment. It is not a receipt for what you actually ate.
Heat, light, water and time
Four forces take vitamin C out of food, and they are worth separating, because you can do something about three of them.
Time and temperature travel together. Lee and Kader's review of the postharvest literature concluded that temperature management after harvest is the most important factor for maintaining vitamin C in fruits and vegetables, with losses accelerated at higher temperatures and with longer storage.5 That is why the fridge helps and why it is not enough. Cold slows the reaction. It does not stop it.
Heat is fast. The 2023 cooking study found boiling costing between 9.83 and 70.88 percent depending on the vegetable, with spinach worst hit. Steaming cost 13.52 to 60.37 percent. Microwaving retained more than 90 percent.6 The pattern is not really about heat alone. It is about heat plus water plus time, which is the exact recipe for a water soluble molecule to leave the food and end up in liquid you pour down the sink.
Light drives oxidation. Work on ultraviolet treatment of a model juice system found ascorbic acid degrading into dehydroascorbic acid and then 2,3-diketogulonic acid, with ascorbyl radicals continuing to form for up to 200 minutes after the light was switched off.7 That last detail is the interesting one. The damage does not stop when the exposure stops.
Water strips it. The salad leaf study found that spinach lost a significant amount of ascorbate after commercial washing, and that leaves submerged in turbulent water lost significantly more than leaves left in air.2 Pre-washed and bagged is a convenience that has a nutritional price attached, and nobody prints it on the bag.
Figure 02
The four things that take vitamin C out of food
What each one does, and whether you can do anything about it.
Swipe to compare
| Force | What it does | Published scale | In your control |
|---|---|---|---|
| Time and temperature | Drives slow oxidation from the moment of harvest onward | 59% mean loss in salad leaves over 10 days at 4°C | Partly. Buy closer to harvest, eat sooner |
| Heat | Breaks the molecule down and speeds every other reaction | Boiling costs 9.83 to 70.88% | Yes. Method changes the number more than heat itself |
| Water | Carries a water soluble vitamin out of the food | Significant loss in spinach after commercial washing | Yes. Avoid long soaks and pre-washed bags |
| Light | Radicals still forming 200 minutes after UV | Triggers photo-oxidation that continues after exposure ends | Rarely. Most of it happens before you see the food |
Sources, in order of the rows: Dewhirst 2017, Razzak 2023, Dewhirst 2017, Tikekar 2011.
Whole food vitamin C and isolated ascorbic acid
This is where a lot of nutritional writing goes wrong in both directions, so it is worth being exact.
Synthetic ascorbic acid is not a different or lesser molecule. It is the same molecule. A 2013 review in Nutrients gathered the animal and human studies, both pharmacokinetic and steady state, and concluded that synthetic and food-derived vitamin C appear to be equally bioavailable.8 Anyone telling you that the vitamin C in a tablet is fake, inert or unusable is telling you something the published evidence does not support, and it is worth being suspicious of the rest of what they are selling.
What genuinely differs is the delivery. Vitamin C in a berry does not arrive alone. It arrives with flavonoids, carotenoids, organic acids, fibre and the water the fruit was holding it in. Whether those companions change what the vitamin does is a live research question, and the same review is candid that the human evidence on isolated bioflavonoids added back to ascorbic acid has been inconsistent.8 The honest position is that the food matrix is a different package, not a proven upgrade.
There is a simpler reason to care about the package anyway, and it does not require any claim about bioavailability at all. If you eat the vitamin C in a berry, you also eat the berry. You get the rest of what is in it. That is a compositional argument rather than an absorption one, and it is the argument that actually holds. It is the same reasoning behind what makes the world's best sea buckthorn, where the case is whole fruit rather than isolated fractions.
Vitamin C in food and vitamin C in a tablet are the same molecule. What changes is everything that comes with it.
The distinction most labels blur
Which berries genuinely carry the most
Now the comparison. Every figure below is per 100 g and every figure has a link. Where a published source gives a range, the range is printed. Ranges this wide are not sloppiness. Ripeness, cultivar, growing altitude, harvest timing and analytical method all move these numbers, and any source giving you a single confident value for a whole species has quietly picked one sample from one paper.
Figure 03
Vitamin C in berries, per 100 g
All values per 100 g of fresh fruit, except camu camu, which is the one figure here measured in juice. Ordered by the top of the published range.
Bar length is a log scale, so the smallest berry is still visible next to the largest. Figures are the top of each published range.
Acerola from Bourafai-Aziez and colleagues, Molecules, 2022. Sea buckthorn from Gâtlan and Gutt, IJERPH, 2021. Camu camu from Nowak and colleagues, Foods, 2023. Black currant from Alzahrani and colleagues, Cureus, 2023. Calafate, blueberry, blackberry and raspberry ranges from Ortiz-Viedma and colleagues, Antioxidants, 2025. Strawberry from Miller and colleagues, Nutrients, 2019. Raspberry cultivar values from Chwil and colleagues, Metabolites, 2023. Cranberry from Nemzer and colleagues, Molecules, 2022.
Three things are worth saying out loud about that table, because they are the parts a marketing page would leave out.
- Sea buckthorn does not win it. Acerola's published range runs higher at the top. Camu camu's directly measured juice figure is extraordinary in its own right. Sea buckthorn is near the top, not at it, and the case for it was never a single nutrient anyway.
- Blueberries are not a vitamin C fruit. At 4 to 8 mg per 100 g they are the weakest entry on this list.9 That is not a criticism. Blueberries earn their place on anthocyanins, the pigments that make them blue. Different fruit, different argument.
- The camu camu figure is juice, not fruit. It sits in a fresh-fruit table because it is the cleanest directly measured number published for that species, but juice and whole fruit are not the same unit, and pretending otherwise is exactly the sloppiness this article is about.
If you want the wider version of this comparison, across compound classes rather than one vitamin, it is in the ten healthiest berries ranked, and the unfamiliar entries get their own piece in eight berries you have never heard of.
The enzyme sea buckthorn does not have
There is one detail in the sea buckthorn literature that belongs in an article about vitamin C degradation more than in an article about sea buckthorn.
Most fruit contains ascorbate oxidase, an enzyme that catalyses the breakdown of vitamin C. It is a large part of why a cut apple browns and why a fruit's vitamin C figure falls through storage and processing. A 2021 review of sea buckthorn composition notes that sea buckthorn berries do not contain ascorbate oxidase, which is why vitamin C persists in processed sea buckthorn products and in dried fruit.10
That is a genuinely unusual trait, and it matters for the whole argument of this article. A high number on a chart is only useful if the food can hold onto it. Sea buckthorn is one of the few fruits where the published figure and the figure at the point of eating are not separated by a large invisible loss.
The same review reports the subspecies split that explains why sea buckthorn's vitamin C figures vary so wildly online. The European rhamnoides subspecies is reported at 0.3 to 3.1 g per kilogram of fruit. The Chinese sinensis subspecies, the one that grows on the Tibetan Plateau, is reported at 2 to 25 g per kilogram, which is up to eight times higher.10 Wild Chinese sea buckthorn on the Qinghai Tibet Plateau grows predominantly above 3,000 metres, about 10,000 feet, and the Tibetan species Hippophae tibetana has been recorded between 3,000 and 5,200 metres.1112 Which subspecies a product came from is therefore a real question with a large numerical answer attached, and it is covered properly in two sources, one berry and in how to choose sea buckthorn.
Figure 04
201 mg against the Nutrient Reference Value
A donut chart would have to lie about a figure over 100 percent, so this is a track with the 100 percent mark shown and a fill that overshoots it.
Source: Human Renaissance Sea Buckthorn Puree nutrition label, 30 mL pouch. NRV = Nutrient Reference Value. That is more vitamin C than an orange, stated without a multiplier because a per-gram density and a per-serving amount are different measurements.
One reason a published per-serving figure is more useful than a species average: it belongs to a specific product made a specific way, and it can be checked. A species average cannot, because the species is not one thing. That is the whole lesson of the table above.
What this changes about how you shop
None of the above is an argument for anxiety about fruit. It is an argument for reading a nutrition figure as what it is: a measurement of a food at one moment, under one method, before anything happened to it.
Practically, the things that protect vitamin C are the same things that make food better anyway. Buy closer to harvest. Eat it sooner. Cook it in less water for less time, or not at all. Do not assume frozen is worse, because the 2007 review found that frozen and canned products can compare well with fresh produce that has spent days in a supply chain.4 And treat any product that leans hard on a vitamin C number without saying where the number came from with the same caution you would give any other unsourced claim. The broader version of that argument, about what modern fruit has been bred toward, is in why your berries are sprayed, and the composition case for one berry in particular is in sea buckthorn, the king of berries.
Frequently asked questions
What does vitamin C actually do in the body?
Three main jobs. It is a cofactor for the lysyl and prolyl hydroxylases that stabilise the structure of collagen, which is the protein scaffold of skin, tendon, blood vessel wall and bone. It is a strong antioxidant because it donates electrons readily. And it accumulates in white blood cells, where research reports it supporting epithelial barrier function and the activity of neutrophils, B cells and T cells.
Does vitamin C break down in storage?
Yes, and faster than most people assume. Salad leaves held for ten days at 4 degrees Celsius in darkness lost an average of 59 percent of their ascorbate across the varieties tested, with baby iceberg lettuce losing 86 percent. In a separate study, tomato lost 71.8 percent of its vitamin C after fourteen days at 4 degrees Celsius. Temperature management after harvest is the single biggest factor.
Does cooking destroy vitamin C?
Cooking method matters more than cooking itself. In one 2023 study, boiling cost between 9.83 and 70.88 percent of the vitamin C depending on the vegetable, steaming cost between 13.52 and 60.37 percent, and microwaving retained more than 90 percent. Vitamin C is water soluble, so most of the loss in boiling is the vitamin leaving the food and going into water that gets poured away.
Is synthetic vitamin C different from the vitamin C in food?
Chemically they are the same molecule, and a 2013 review of animal and human studies concluded that synthetic and food-derived vitamin C appear to be equally bioavailable. What differs is everything else in the package. Food delivers ascorbic acid alongside flavonoids, carotenoids, acids and fibre, while an isolated tablet delivers the molecule alone. That is a difference in what arrives with it, not a difference in the vitamin.
Which berry has the most vitamin C?
Acerola, on the published ranges. Reviews put acerola fruit at 500 to 4,500 mg per 100 g. Sea buckthorn of the Chinese sinensis subspecies is next at 200 to 2,500 mg per 100 g. Camu camu juice has been directly measured at 8,410.8 mg per kilogram, which is 841 mg per 100 g of juice. All three of those ranges are wide, because ripeness, subspecies and analytical method move the number a long way.
Do blueberries have much vitamin C?
No. Published figures put blueberries at 4 to 8 mg of ascorbic acid per 100 g, which is the lowest of the common berries. Blackberries run 6 to 19 mg and raspberries 18 to 40 mg. Blueberries earn their reputation on anthocyanins, the pigments that make them blue, not on vitamin C.
How much vitamin C is in sea buckthorn?
It depends heavily on the subspecies. The European rhamnoides subspecies is reported at 0.3 to 3.1 g per kilogram of fruit, which is 30 to 310 mg per 100 g. The Chinese sinensis subspecies, the one that grows on the Tibetan Plateau, is reported at 2 to 25 g per kilogram, which is 200 to 2,500 mg per 100 g. Human Renaissance's published label figure is 201 mg of vitamin C per 30 mL pouch, 223% NRV.
Why does sea buckthorn hold its vitamin C better than most fruit?
Because the berries do not contain ascorbate oxidase, the enzyme that drives vitamin C degradation in most fruit. A 2021 review notes that this is why vitamin C persists in processed and dried sea buckthorn products. It is an unusual trait, and it is the reason a sea buckthorn figure on a label is less likely to be a figure that has already left the food by the time you open the package.
Sources
- Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients, 2017;9(11):1211. PMC5707683
- Dewhirst RA, Clarkson GJJ, Rothwell SD, Fry SC. Novel insights into ascorbate retention and degradation during the washing and post-harvest storage of spinach and other salad leaves. Food Chemistry, 2017;233:237-246. PMC5441274
- Galani JHY, Patel JS, Patel NJ, Talati JG. Storage of Fruits and Vegetables in Refrigerator Increases their Phenolic Acids but Decreases the Total Phenolics, Anthocyanins and Vitamin C with Subsequent Loss of their Antioxidant Capacity. Antioxidants, 2017;6(3):59. PMC5618087
- Rickman JC, Barrett DM, Bruhn CM. Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1, Vitamins C and B and phenolic compounds. Journal of the Science of Food and Agriculture, 2007;87(6):930-944. doi.org/10.1002/jsfa.2825
- Lee SK, Kader AA. Preharvest and postharvest factors influencing vitamin C content of horticultural crops. Postharvest Biology and Technology, 2000;20(3):207-220. doi.org/10.1016/S0925-5214(00)00133-2
- Razzak A, Mahjabin T, Khan MRM, Hossain M, Sadia U, Zzaman W. Effect of cooking methods on the nutritional quality of selected vegetables at Sylhet City. Heliyon, 2023;9(11):e21709. PMC10660054
- Tikekar RV, Anantheswaran RC, Elias RJ, LaBorde LF. Ultraviolet-induced oxidation of ascorbic acid in a model juice system, identification of degradation products. Journal of Agricultural and Food Chemistry, 2011;59(15):8244-8248. pubmed 21699245
- Carr AC, Vissers MCM. Synthetic or Food-Derived Vitamin C, Are They Equally Bioavailable? Nutrients, 2013;5(11):4284-4304. PMC3847730
- Ortiz-Viedma J, Vergara C, Toledo T, et al. Calafate (Berberis buxifolia Lam.) Berry as a Source of Bioactive Compounds with Potential Health-Promoting Effects, A Critical Review. Antioxidants, 2025;14(11):1272. PMC12649473
- Gâtlan AM, Gutt G. Sea Buckthorn in Plant Based Diets, An Analytical Approach of Sea Buckthorn Fruits Composition. International Journal of Environmental Research and Public Health, 2021;18(17):8986. PMC8431556
- NIH National Library of Medicine. Genome and distribution work on Hippophae tibetana, recorded at 3,000 to 5,200 metres. PMC9797102
- NIH National Library of Medicine. High altitude adaptation of sea buckthorn on the Qinghai Tibet Plateau. PMC11015584
- Bourafai-Aziez A, Jacob D, Charpentier G, et al. Development, Validation, and Use of 1H-NMR Spectroscopy for Evaluating the Quality of Acerola-Based Food Supplements and Quantifying Ascorbic Acid. Molecules, 2022;27(17):5614. PMC9458237
- Nowak D, Gośliński M, Przygoński K, Wojtowicz E. Averrhoa carambola L., Cyphomandra betacea, Myrciaria dubia as a Source of Bioactive Compounds of Antioxidant Properties. Foods, 2023;12(4):753. PMC9955449
- Alzahrani MA, Binnshwan FM, Alsulaim KB, et al. Effect of Blackcurrant Consumption on the Genitourinary System, A Literature Review. Cureus, 2023;15(8):e44181. PMC10460296
- Miller K, Feucht W, Schmid M. Bioactive Compounds of Strawberry and Blueberry and Their Potential Health Effects Based on Human Intervention Studies. Nutrients, 2019;11(7):1510. PMC6683271
- Chwil M, Matraszek-Gawron R, Kostryco M. Rubi idaei fructus as a Source of Bioactive Chemical Compounds. Metabolites, 2023;13(11):1124. PMC10673471
- Nemzer BV, et al. Cranberry, Chemical Composition, Antioxidant Activity and Impact on Human Health, Overview. Molecules, 2022;27(5):1503. PMC8911768
