What does vitamin C do in the body? And why do you need a regular intake? Explore its role in immunity, collagen, healing and everyday wellbeing.
🕒 6 min read
What does vitamin C do?
Vitamin C, otherwise known as ascorbic acid, supports the immune system, helps the body make collagen and improves iron absorption. It also helps protect cells from oxidative stress and contributes to normal energy release. These functions help explain why vitamin C matters for skin, blood vessels, bones and cartilage as well as immunity.2
| Function | What it supports |
|---|---|
| Immune function | The normal working of the immune system |
| Collagen formation | Normal skin, blood vessels, bones and cartilage |
| Antioxidant activity | Protection of cells from oxidative stress |
| Iron absorption | Absorption of iron from food |
| Energy metabolism | Normal energy release and reduced tiredness and fatigue |
| Nervous system | Normal nervous system function |
Why does the body need vitamin C regularly?
Vitamin C is a water-soluble vitamin. Unlike most animals, humans cannot make it, so we depend on dietary sources. A regular intake is needed to supply the many processes that use it. Think of it as an everyday nutrient, rather than something to consider only when a cold arrives.5
Vitamin C 500mg
Chewable vitamin C for your daily routine
- 500mg vitamin C per chewable tablet
- With citrus bioflavonoids
- Supports normal immune function
- Suitable for vegans
Why is vitamin C important for immunity?
Vitamin C contributes to normal immune function, helping the body's natural defences work properly. It is also an antioxidant: it helps protect cells from oxidative stress caused by unstable molecules called free radicals.2
Can vitamin C help with the common cold?
Many studies have investigated vitamin C and colds. A Cochrane review found that taking it regularly shortened cold duration by about 8% in adults on average and also reduced severity. Regular supplements did not reduce the number of colds in the general population; starting vitamin C after symptoms began showed no consistent benefit.3
For everyday immune support, aim for a routine you can maintain: varied meals, adequate sleep and regular activity, with supplements chosen to suit your needs.
Vitamin C for skin, healing, bones and cartilage
Ascorbic acid is vital for the synthesis of collagen, a structural protein in blood vessels, bones, cartilage and skin. Collagen helps hold tissues together and is important for wound healing. This explains why wounds can heal poorly when someone is deficient in vitamin C.5
Its role in normal collagen formation makes vitamin C relevant to skincare and joint-health routines. Nutritional support helps provide the building blocks your body uses; it does not mean a higher dose will necessarily produce firmer skin or faster healing.
Vitamin C and iron absorption
Vitamin C helps the body absorb non-haem iron, the type found in plant foods. Adding peppers to a bean salad or fruit alongside an iron-containing meal is an easy way to put this into practice.5
What are the best dietary sources of vitamin C?
Vitamin C is present in a wide variety of fruit and vegetables. Good sources include oranges, strawberries, blackcurrants, peppers, broccoli, Brussels sprouts and potatoes.1
- Add fruit to breakfast or keep it ready as a snack.
- Use sliced peppers in sandwiches, salads or stir-fries.
- Include a variety of vegetables with your main meals.
What happens if you are deficient in vitamin C?
You may remember stories of sailors developing scurvy during long voyages with little fresh fruit or vegetables. Scurvy is caused by severe vitamin C deficiency. It is rare today, but can still occur when intake is very low over a long period.5
Possible signs include weakness, tiredness, painful joints, easy bruising and swollen or bleeding gums. Poor wound healing is another reason to seek advice. These symptoms can have other causes, so speak to a GP rather than assuming a supplement will resolve them.4
Who may be at greater risk?
Risk is higher when someone eats very little food or has few fruit and vegetables, including because of an eating disorder or treatment-related sickness. Smoking and long-term alcohol or drug dependency affecting diet can also increase risk. During pregnancy or breastfeeding, a poor diet can make it harder to meet increased needs.4
If you are at risk and develop bleeding gums or unusual easy bruising, seek an urgent GP appointment or NHS 111 advice.4
The role of vitamin C supplements
Ideally, we would obtain sufficient vitamin C from a healthy, balanced diet. A supplement offers a convenient, clearly measured serving alongside that diet. Choosing a format you enjoy taking can help make it part of your usual routine.
Browse our vitamin C supplements to compare chewable tablets and other formulations. For a non-acidic option, Gentle-C uses calcium ascorbate.
Gentle-C
Non-acidic calcium ascorbate
- A formulation option for sensitive stomachs
- Vitamin C supports immunity and normal collagen formation
- One tablet daily with water
- Suitable for vegans
Choosing your supplement
Once you've chosen your formulation, remember to choose a reputable supplier that clearly states the strength and ingredients. Compare the amount of vitamin C per daily serving, not just the weight of the ingredient compound. For example, calcium ascorbate weight and the vitamin C it supplies are different figures.
How much vitamin C do you need?
The NHS advises 40mg a day for adults aged 19 to 64. This is a dietary requirement, rather than a recommended supplement dose. Most people can meet it through a varied diet. Follow your supplement's label and include any vitamin C already supplied by other products.1
Dosage and safety
The NHS notes that more than 1,000mg a day can cause stomach pain, diarrhoea or wind. A higher dose is not automatically a better fit. If you experience stomach trouble, review the amount you take and ask a pharmacist about an alternative formulation.1
Check with a healthcare professional before supplementing if you take prescribed medicines, are pregnant or breastfeeding, or have a medical condition. This is particularly relevant if you have kidney disease, a history of kidney stones or an iron-overload disorder.5
Vitamin C FAQs
What does vitamin C do for the body?
Vitamin C supports normal immunity, collagen formation, energy release and iron absorption. It also helps protect cells from oxidative stress. Its roles extend beyond winter wellness to everyday functions in skin, bones, cartilage and blood vessels.2
Why does the body need vitamin C every day?
Humans cannot make vitamin C, so food is our starting point. A regular intake keeps this essential nutrient available for the body's daily work. Include fruit and vegetables across your meals; a supplement can provide a convenient, measured amount when you choose to complement your diet.5
Does vitamin C help with colds?
Regular supplementation has been linked with slightly shorter colds. The Cochrane review found an average reduction of 8% in adults, but no reduction in how often the general population caught colds. Starting supplements only after symptoms appeared did not show a consistent benefit.3
How much vitamin C do adults need?
Which foods contain vitamin C?
Oranges, strawberries, blackcurrants, peppers, broccoli, Brussels sprouts and potatoes are useful sources. Variety makes it easier to fit vitamin C into your day: try fruit with breakfast, peppers with lunch and broccoli with dinner.1
Is vitamin C good for skin?
Vitamin C is needed to make collagen, the structural protein in skin and other tissues. Getting enough supports this normal process. Oral supplements and topical skincare are different products, so claims about a serum should not automatically be applied to a tablet.5
Can I take vitamin C with iron?
Vitamin C improves absorption of non-haem iron, including iron from plant foods. Pair lentils or beans with peppers or tomatoes for a practical food combination. If you take prescribed iron, follow the treatment instructions and ask your pharmacist whether an additional vitamin C supplement is appropriate.5
What is the difference between ordinary and gentle vitamin C?
Ascorbic acid is a common form of vitamin C. Gentle-C uses non-acidic calcium ascorbate, offering a formulation choice for people who prefer this form. Compare the actual vitamin C amount on the nutritional label, the daily serving and whether the product is chewable or swallowed.
When should I take a vitamin C supplement?
Choose a time that fits your routine and follow the product's directions. There is no need to build your day around a particular hour. Check the label before chewing or swallowing, and remember to count vitamin C in any multivitamin you already use.
