Collagen gives your skin its strength, and your body needs vitamin C to make it. This link is well enough established to be an authorised health claim in the UK. Here we look at how it works, what the research on vitamin C-rich foods shows, and how much you really need.
How vitamin C is involved in collagen formation
Collagen is the main structural protein in the dermis, the deeper layer of your skin. It keeps skin firm.
To build stable collagen, your cells rely on two enzymes. Vitamin C acts as a co-factor for both of them, helping to stabilise the collagen molecule's structure. Lab studies also suggest vitamin C encourages the genes that make collagen (Pullar et al., 2017).
The official wording on the Great Britain health claims register is: vitamin C contributes to normal collagen formation for the normal function of skin (DHSC).
Skin holds a lot of vitamin C, much more than blood does. The outer layer (epidermis) usually contains two to five times more than the dermis. Some studies find lower levels in older or sun-damaged skin. But it is not yet clear whether low vitamin C is a cause or a result of that damage (Pullar et al., 2017).
What the research on food and skin shows
The kiwifruit study
In 2025, researchers at the University of Otago in New Zealand published a study in the Journal of Investigative Dermatology (Pullar et al., 2025). It had two stages.
First, they compared vitamin C in blood with vitamin C in healthy skin samples from people having planned surgery. Skin levels closely followed blood levels.
Second, 24 healthy adults (12 in New Zealand and 12 in Germany) ate two SunGold kiwifruit a day for eight weeks. That is about 250 mg of vitamin C a day. Skin samples were taken before and after. Ultrasound tests in the German group showed a significant increase in skin thickness, which the researchers say reflects collagen production. They also reported faster renewal of the outer skin layer (University of Otago).
These results need some context:
- The food part of the study was small, with only 24 people.
- There was no comparison group. Everyone ate kiwifruit.
- Collagen was not measured directly. It was inferred from skin thickness.
- The study was part-funded by Zespri, a kiwifruit company.
- Only one food was tested, so we can't be sure other vitamin C-rich foods would do the same.
Larger population studies
An older US study looked at the diets of 4,025 women aged 40 to 74. Dermatologists examined their skin. Women with higher vitamin C intakes were less likely to have a wrinkled appearance or age-related skin dryness. This held true after allowing for age, sun exposure, income, body weight and other factors (Cosgrove et al., 2007).
However, this type of study shows a link, not cause and effect. The researchers also worked for Unilever, a skincare company.
It also helps to remember that natural skin ageing depends largely on your genes. Long-term sun exposure is a major outside cause of early skin ageing, and smoking and pollution speed it up too. That makes it hard to separate the effect of any single nutrient (Pullar et al., 2017).
Good to know: Skin vitamin C seems to rise mainly when blood levels start low. Once blood levels are topped up, adding more may not raise skin levels further (Pullar et al., 2017). So getting enough every day matters more than taking huge amounts.
How much vitamin C do you need?
The NHS says adults aged 19 to 64 need 40 mg of vitamin C a day. Your body can't store it, so you need some every day. Most people can get all they need from a varied diet (NHS).
Taking more than 1,000 mg a day can cause stomach pain, diarrhoea and wind. These symptoms should go once you stop the supplement. The NHS says less than 1,000 mg a day from supplements is unlikely to cause harm (NHS).
What about liposomal vitamin C?
Liposomal vitamin C is wrapped in tiny fat-based bubbles called liposomes. The UK's Committee on Toxicity reviewed the evidence in 2025. It found six small human studies, with between 2 and 24 people each. Overall, liposomal forms appeared to increase how much vitamin C reached the blood (COT, 2025).
In one of those trials, 11 adults took 4 g of vitamin C in different forms. Liposomal vitamin C gave higher blood levels than standard vitamin C, but lower levels than a drip (Davis et al., 2016). These studies measured blood levels only, not skin.
What you can do
- Eat vitamin C-rich foods daily. Good sources include oranges, peppers, strawberries, blackcurrants, broccoli, brussels sprouts and potatoes (NHS).
- Protect your skin from the sun. Long-term sun exposure is a major cause of premature skin ageing (Pullar et al., 2017).
- Don't smoke. Smoking speeds up skin ageing (Pullar et al., 2017).
- Consider a supplement if your diet falls short. Vitamin C contributes to normal collagen formation for the normal function of skin. ivvion's Liposomal Vitamin C 2600 mg gives 1,820 mg of vitamin C per four-capsule daily serving. That is above the 1,000 mg level the NHS mentions, so check the label and ask a pharmacist if you're unsure what amount suits you.
- Collagen supplements. Our marine collagen guide explains the research. Collagen has no authorised health claims in the UK. Nano Marine Collagen is a food supplement, not a treatment.
Speak to your GP or pharmacist before taking supplements if you're pregnant or breastfeeding, have a health condition (such as kidney problems), or take regular medicines, including blood thinners.
Frequently asked questions
How much vitamin C do I need for healthy skin?
There is no separate amount for skin. The NHS reference amount for adults is 40 mg a day, which most people get from food. The kiwifruit study used about 250 mg a day from fruit.
Is vitamin C from food better than supplements?
Food gives you vitamin C along with fibre and other nutrients, so it should come first. Supplements can help if your diet is limited. The kiwifruit study looked at food, not supplements.
Can I take too much vitamin C?
Yes. More than 1,000 mg a day can cause stomach pain, diarrhoea or wind in some people. These effects usually stop when you cut back (NHS).
Do vitamin C creams work the same way?
Not quite. Vitamin C doesn't pass easily through the skin's outer barrier. Researchers describe the effects of creams as poorly understood (Pullar et al., 2017).
Will vitamin C get rid of wrinkles?
No food or supplement can promise that. Studies link higher vitamin C intake with better skin appearance, but they don't prove cause and effect. Limiting sun exposure, not smoking and eating well are the habits researchers point to for skin ageing (Pullar et al., 2017).
Sources
- Cosgrove MC, Franco OH, Granger SP, Murray PG, Mayes AE (2007). Dietary nutrient intakes and skin-aging appearance among middle-aged American women. American Journal of Clinical Nutrition 86(4):1225–31. PubMed
- Committee on Toxicity (2025). Annex A: Discussion paper on novel formulations of supplement compounds designed to increase oral bioavailability. Case study 1: Liposomal vitamin C. cot.food.gov.uk
- Davis JL et al. (2016). Liposomal-encapsulated ascorbic acid: influence on vitamin C bioavailability and capacity to protect against ischemia–reperfusion injury. Nutrition and Metabolic Insights 9:25–30. PMC
- Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. GOV.UK
- NHS. Vitamin C. nhs.uk
- Pullar JM, Carr AC, Vissers MCM (2017). The roles of vitamin C in skin health. Nutrients 9(8):866. PMC
- Pullar JM, Bozonet SM, Segger D et al. (2025). Improved human skin vitamin C levels and skin function after dietary intake of kiwifruit: a high-vitamin-C food. Journal of Investigative Dermatology. PubMed
- University of Otago. News release on the kiwifruit and skin vitamin C study. otago.ac.nz