Vitamin C Benefits: What Does Vitamin C Do?

Vitamin C is probably best known for its role in supporting the immune system, but that's only part of the story. Your body also needs vitamin C to make collagen, protect cells from oxidative stress and help you absorb iron. It supports the nervous system too and can help reduce tiredness and fatigue.

Unlike some nutrients, our bodies can't store vitamin C, so we need to get it regularly through our diet. Fortunately, vitamin C is found in plenty of everyday fruits and vegetables. So what exactly does it do, how much do we need and when might a supplement be worth considering?

What Is Vitamin C?

Vitamin C, also known as ascorbic acid, is an essential water-soluble vitamin. As our bodies can't make or store it, we need to get vitamin C regularly from the foods we eat. Fruit and vegetables are our main dietary sources, with foods such as peppers, citrus fruits, berries, broccoli and potatoes all contributing vitamin C.

Vitamin C also acts as an antioxidant and has a number of other important jobs throughout the body.

What Are the Benefits of Vitamin C?

Vitamin C is involved in everything from immune function and collagen formation to iron absorption. Here's a closer look at some of its most important roles.

1. Vitamin C Supports Your Immune System

This is probably the benefit most of us associate with vitamin C. Vitamin C supports the normal function of the immune system, which is why it often gets more attention during the colder months.

Your immune system needs nutrients all year round, so rather than thinking of vitamin C as something to reach for only when winter arrives, it's better to include vitamin C-rich foods regularly as part of a balanced diet.

2. Vitamin C Helps Your Body Make Collagen

Vitamin C has an important role in helping your body make collagen. Collagen is a structural protein found throughout the body, including in your skin, bones, cartilage and blood vessels. Our bodies make collagen naturally, and vitamin C is one of the nutrients needed for that process.

This is one of the reasons vitamin C is often associated with skin health, but its role in collagen formation extends well beyond the skin.

Want to learn more about collagen? Read our guide to the health benefits of collagen.

3. Vitamin C Helps Protect Your Cells

Vitamin C is an antioxidant, which means it helps protect cells from oxidative stress. Oxidative stress occurs when there's an imbalance between free radicals and the body's ability to deal with them.

Rather than thinking of antioxidants as something that “detoxes” the body, it's more useful to think of vitamin C as one of the nutrients involved in the body's normal systems for protecting its cells.

4. Vitamin C Helps Your Body Absorb Iron

Vitamin C can help increase the amount of iron your body absorbs, particularly the non-heme iron found in plant foods. This can be especially useful if much of your dietary iron comes from foods such as beans, lentils, tofu, seeds and leafy green vegetables. You don't need a complicated combination. Simply pairing an iron-rich plant food with a source of vitamin C can help.

For example:

• lentils with tomatoes or peppers
• beans with peppers
• leafy greens with a squeeze of lemon
• iron-fortified cereal with berries

For more ideas, read our guide to iron-rich foods.

5. Vitamin C Helps Your Body Release Energy From Food

Vitamin C is involved in the processes your body uses to release energy from the food you eat. It can also help with the reduction of tiredness and fatigue. This doesn't mean taking extra vitamin C will automatically give you more energy, or that tiredness means you're low in vitamin C. Fatigue can have lots of different causes. Instead, vitamin C is one of many essential nutrients your body needs to function normally.

6. Vitamin C Supports Your Nervous System

Vitamin C also helps support the normal functioning of your nervous system. Your nervous system includes your brain, spinal cord and the network of nerves that carry messages throughout your body.

Vitamin C also supports normal psychological function, another example of how its role in the body extends beyond immunity.

What Foods Are High in Vitamin C?

Getting enough vitamin C doesn't have to mean eating an orange every day. It's found in a wide range of fruit and vegetables, including:

• peppers
• oranges and other citrus fruits
• strawberries
• blackcurrants
• broccoli
• Brussels sprouts
• potatoes

Eating a varied selection of fruit and vegetables throughout the day is a straightforward way to include vitamin C alongside plenty of other useful nutrients.

Vitamin C can be affected by prolonged storage and cooking, particularly boiling in water. Including a mixture of fresh and cooked fruit and vegetables can therefore be a practical approach.

How Much Vitamin C Do I Need?

According to the HSE, adults aged 19 to 64 need 40mg of vitamin C each day. Most people should be able to get all the vitamin C they need by eating a varied, balanced diet. Because your body doesn't store vitamin C, it's important to include sources of it regularly rather than trying to get a large amount occasionally.

What Happens If You Don't Get Enough Vitamin C?

Severe vitamin C deficiency is uncommon when you're eating a varied diet containing fruit and vegetables. However, going without enough vitamin C for a prolonged period can eventually lead to scurvy. Rather than trying to diagnose a vitamin C deficiency based on symptoms yourself, speak to a healthcare professional if you're concerned about your diet or nutritional status.

Should You Take a Vitamin C Supplement?

Not necessarily. For most people, a varied diet containing plenty of fruit and vegetables should provide the vitamin C they need. A supplement can provide another convenient source of vitamin C, however, particularly if your diet is limited or you find it difficult to regularly include vitamin C-rich foods.

Vitamin C supplements come in many different forms, including:

• tablets and capsules
• chewable tablets
• powders
• gummies
• liquids
• sprays
• liposomal vitamin C

The best option isn't necessarily the one with the highest dose. Think about how much vitamin C the product provides, how you prefer to take supplements and what will realistically fit into your routine.

Explore our vitamin C supplements to compare the different options available.

What Is Liposomal Vitamin C?

Liposomal vitamin C is vitamin C carried within tiny structures made from phospholipids, known as liposomes.

You'll sometimes see claims that this makes vitamin C dramatically better absorbed than conventional supplements. There is research investigating whether liposomal delivery can affect absorption, but that doesn't mean everyone needs liposomal vitamin C or that conventional vitamin C supplements aren't absorbed.

It's better to think of liposomal vitamin C as another supplement format, rather than automatically the best form for everyone. If you're considering it, read our dedicated guide to liposomal vitamin C for a closer look at how it works and how it compares with conventional vitamin C.

You can also explore our liposomal vitamin C range.

What About Vitamin C and Zinc?

Vitamin C and zinc are often found together in supplements because both nutrients support the normal function of the immune system. That doesn't mean they have to be taken together, but a combined product can be convenient if you're looking to supplement both.

You can explore our vitamin C and zinc range to compare combination products.

Can You Take Too Much Vitamin C?

Yes – taking more isn't necessarily better. According to the HSE, taking more than 1,000mg of vitamin C per day from supplements can cause digestive effects including stomach pain, diarrhoea and flatulence. The HSE advises that taking less than 1,000mg per day from vitamin C supplements is unlikely to cause harm.

As with any supplement, follow the directions on the product rather than assuming a higher dose will provide greater benefits.

When Is the Best Time to Take Vitamin C?

For most people, there isn't one special time of day when vitamin C has to be taken. If you're using a supplement, the most practical approach is usually to follow the product directions and take it at a time that fits comfortably into your routine.

If you're taking vitamin C specifically alongside an iron-containing meal or supplement, taking the two together may be useful because vitamin C helps increase iron absorption.

The Evergreen View

Vitamin C deserves its reputation as an important nutrient, but there's much more to it than winter immune support.

It helps your body make collagen, supports your immune and nervous systems, helps protect cells from oxidative stress and makes it easier to absorb iron from your diet. It can also help reduce tiredness and fatigue.

For most people, food is the best place to start. A varied diet containing plenty of fruit and vegetables should  provide the vitamin C you need. If you'd like to supplement your intake, don't assume that the biggest dose or most expensive formulation is automatically better. Choose a product and format that suits your needs and follow the recommended directions.

Explore our vitamin C supplements, including tablets, capsules, powders, gummies, sprays and liquids, or discover our dedicated ranges of liposomal vitamin C and vitamin C and zinc.

Checked and updated: 23rd September 2026