Vitamin C

What is Vitamin C and why can't the body produce it on its own?

Vitamin C (scientifically known as ascorbic acid) is a water-soluble vitamin that the human body – unlike most mammals – cannot synthesise on its own. We lack the key enzyme required to do so, meaning we are entirely dependent on intake from food or dietary supplements.

In the body, Vitamin C serves two essential roles:

1. It is a powerful antioxidant – neutralising free radicals and protecting cells from oxidative damage.
2. It acts as an essential cofactor in hundreds of enzymatic reactions: without adequate levels of ascorbic acid, the body cannot properly synthesise collagen, carnitine, or key neurotransmitters such as dopamine or noradrenaline.

In other words: Vitamin C is not just a "winter immune supplement" – it is a substance upon which your energy levels, recovery, tissue integrity, and nervous system function depend every single day.

What does Vitamin C do – what do you actually need Vitamin C for in your body?

Vitamin C is not a substance with just one function. It works throughout the entire body – and where it is lacking, you will feel it sooner or later.

• Immunity – Vitamin C boosts the activity of immune cells and helps the body defend itself against infections. Regular supplementation reduces the duration of the common cold by an average of 8% in adults and 14% in children (Hemilä & Chalker, 2013)
• Collagen – without Vitamin C, the body simply cannot produce collagen. The effects of deficiency will show in your skin, hair, joints, and how quickly you recover from injury
• Energy and metabolism – Vitamin C is involved in the production of carnitine, which transports fats to the mitochondria for burning. Less Vitamin C = less energy
• Iron absorption – Vitamin C improves the absorption of iron from plant-based sources, which is particularly important for vegetarians, vegans, and pregnant women
• Mental health and nervous system – Vitamin C is essential for the production of dopamine and noradrenaline. Deficiency can manifest as irritability, low mood, or poor concentration
• Protection against oxidative stress – as a powerful antioxidant, it protects cells from damage caused by intense exercise, stress, or illness

Vitamin C for hair and skin

Vitamin C has a direct impact on the health of your hair and skin – and this is precisely because of collagen. Collagen and Vitamin C simply go hand in hand. As soon as Vitamin C levels drop, the body produces less collagen in the skin, hair becomes more brittle, and wounds heal more slowly. Research also confirms that an adequate intake of Vitamin C helps protect the skin from UV-induced damage and contributes to its elasticity (Pullar et al., 2017).

Tip: Explore our skin, complexion and hair category.

Forms of Vitamin C in supplements: Which product should you choose?

Not all dietary supplements containing Vitamin C are created equal – the form and processing technology determine how much active ingredient actually reaches where the body needs it.

Ascorbic acid

Ascorbic acid is the classic and most widely used form. At doses up to 200 mg, it achieves a bioavailability of over 90% – meaning that from every 100 mg of Vitamin C you take, 90 mg or more actually reaches the bloodstream. At higher doses, the intestine struggles to keep up – the transport proteins that carry Vitamin C across the intestinal wall have a limited capacity, and at 1,000 mg of Vitamin C they become saturated – causing absorption to drop to 50–70% (Levine et al., 1996). The remainder is unused by the body and excreted via stools or urine.

It is a practical and cost-effective choice for most people – although those with more sensitive stomachs may experience mild irritation.

Mineral ascorbates

Mineral ascorbates (sodium ascorbate, calcium ascorbate, magnesium ascorbate) are salts of ascorbic acid with a neutral pH, making them considerably gentler on the stomach. If standard ascorbic acid irritates your stomach, this is a logical alternative with comparable efficacy.

Vitamin C with rosehip, sea buckthorn, and other natural extracts

If you prefer natural Vitamin C, opt for products containing rosehip or sea buckthorn extract – these naturally combine ascorbic acid with bioflavonoids and other phytonutrients that can complement the antioxidant effect.

Vitamin C with rosehip combines ascorbic acid with natural bioflavonoids and other compounds from rosehip extract.

Rosehip extract is not merely a carrier for Vitamin C, however. Research shows that rosehip itself has anti-inflammatory properties that may contribute to joint health – this effect is attributed to specific phytonutrients within the extract itself, independent of the ascorbic acid content. The combination of Vitamin C with rosehip may therefore make sense not only as antioxidant protection, but also as support for the musculoskeletal system.

Another popular option is Vitamin C with sea buckthorn – its berries are among the most abundant natural sources of ascorbic acid, and they also naturally contain carotenoids. For those who want more than just an isolated active ingredient, this is a sensible choice.

Vitamin C and rutin

Rutin is a natural flavonoid that occurs naturally in rosehips, citrus fruits, and buckwheat. In combination with Vitamin C, it does not simply act as a supplement – research shows that rutin has its own antioxidant and anti-inflammatory properties, which can work synergistically with Vitamin C in protecting cells from oxidative stress (Omar et al., 2022). It is therefore a combination in which each component plays its own part.

Sustained-release Vitamin C (long effect)

Products labelled as "Vitamin C long effect" or "slow release" use a special matrix that releases ascorbic acid gradually over a period of 8–12 hours. The advantage is clear: intestinal transporters are not overwhelmed all at once, meaning a greater proportion of the dose is absorbed. Particularly suitable for those taking Vitamin C 1,000 mg or more per day.

Liposomal Vitamin C

Liposomal Vitamin C represents the most technologically advanced form of Vitamin C in dietary supplements currently available. Ascorbic acid is encapsulated within phospholipid vesicles (liposomes), which mimic the structure of cell membranes. This allows them to penetrate directly into cells via the mechanism of endocytosis, bypassing dependency on saturable intestinal transporters.

A study by Purpura et al. (2024) suggests that after taking a liposomal Vitamin C supplement, your body absorbs 21% more than from a standard tablet. A broader review of studies by Carr (2025) indicates that the difference may be even more pronounced – up to 5× higher blood levels, depending on the specific formulation.

This is the most expensive form – but the one with the strongest scientific backing for maximum bioavailability.

Vitamin C powder

Vitamin C powder offers flexible dosing – it can easily be added to a drink, smoothie, or water. It is ideal for those who do not want to swallow tablets or who wish to precisely regulate their Vitamin C intake. Absorption is comparable to tablet-form ascorbic acid.

Vitamin C effervescent tablets

Vitamin C effervescent tablets are popular for their ease of use and pleasant taste – they can also help you increase your daily fluid intake. Vitamin C may be absorbed somewhat faster than from a standard tablet. A potential drawback is the higher sodium content found in some products.

Clear comparison of Vitamin C forms

Daily dose of Vitamin C: How much do you actually need?

The basic rule is: Food first, supplements second. Wondering which foods contain Vitamin C? Red pepper, blackcurrant, grapefruit, rosehip, kiwi, and broccoli can all easily cover the recommended daily intake – provided you eat them regularly and fresh.

There is one important caveat, however: Bear in mind that Vitamin C is what is known as thermolabile – meaning that cooking, steaming, or baking causes vegetables to lose 25–50% of their Vitamin C content. So if your diet is predominantly made up of cooked or unvaried foods, your daily requirements may be harder to meet through diet alone than you might think.

Reference intake values (EFSA, 2019):

• Adults: 80–100 mg/day
• Pregnant women: 100–120 mg/day
• Breastfeeding women: 120–150 mg/day
• Vitamin C for children: 20–75 mg/day depending on age
• Smokers: 35–50 mg/day more than non-smokers
• Athletes under intense training loads: a minimum of 200 mg/day to saturate plasma levels (Carr & Maggini, 2017); in practice, endurance athletes under high training loads may use doses of up to 500 mg/day.

The upper safe limit is 2,000 mg/day (EFSA). Vitamin C overdose above this threshold typically manifests as diarrhoea or nausea; in predisposed individuals, it may increase the risk of kidney stones. Vitamin C is water-soluble, so chronic toxicity is rare.

One thing to bear in mind: If you have kidney problems or are taking medications that place a burden on the kidneys, doses above 2 g per day are not advisable without consulting a doctor. In otherwise healthy individuals, this risk is practically non-existent.

If you are taking warfarin, it is advisable to consult your doctor before starting higher doses of Vitamin C. Some cases suggest a possible interaction with its efficacy, although the clinical impact is not conclusive.

When should you take Vitamin C?

When should you take Vitamin C? Morning or evening, before or after meals? This question comes up often, yet the timing of Vitamin C is not particularly critical – you can take Vitamin C at any time. However, if ascorbic acid irritates your stomach, take it with food or opt for mineral ascorbates. If you are taking higher doses (i.e. above 200 mg), it is worth splitting them into two portions throughout the day – the body will absorb more this way than from one large dose taken all at once.

Combinations with Vitamin C

Vitamin C and iron

Iron and Vitamin C – one of the most important combinations. Vitamin C enhances the absorption of non-haem iron from plant-based sources (legumes, dark leafy greens, cereals), which is crucial for vegetarians, vegans, and pregnant women.

Vitamin C and zinc

Vitamin C and zinc is a popular combination in dietary supplements marketed "for immunity". Both micronutrients support immune function through complementary mechanisms – Vitamin C as an antioxidant and modulator of immune response, and zinc as a cofactor for hundreds of enzymes.

Vitamin C + D3

Vitamin C and D3 each support immunity in their own way. While Vitamin C works directly within immune cells (boosting their activity and protecting them from damage), Vitamin D3 acts more like a conductor – regulating the genes that govern the body's immune defences.

A direct synergy between them has not been scientifically proven, but the combination has a different, practical argument: in the UK, an estimated 40–50% of the population suffers from Vitamin D deficiency during winter – and this is precisely when the need for Vitamin C also increases. A C + D3 supplement may therefore be a sensible choice for autumn and winter – covering both deficiencies at once.

Who should supplement Vitamin C? Groups with increased requirements

Scientific evidence clearly identifies groups for whom Vitamin C supplementation is particularly warranted:

• Smokers – smoke increases the body's consumption of Vitamin C by 50%
• Athletes – intense exercise increases oxidative stress and demands on the immune system
• Pregnant and breastfeeding women – higher requirements for foetal development and breast milk production
• Children in group settings – immune support where infections spread most quickly
• Individuals in recovery – Vitamin C accelerates healing and tissue regeneration
• Vegetarians and vegans – a key ally in absorbing iron from plant-based sources
• People under chronic stress – stress increases Vitamin C consumption in the adrenal glands

How to choose the best Vitamin C? Summary and recommendations

• Looking for a reliable and cost-effective solution? → Ascorbic acid
• Does ascorbic acid irritate your stomach? → Mineral ascorbates
• Do you prefer a natural approach? → Vitamin C with rosehip, sea buckthorn, or rutin
• Taking higher doses (500 mg+)? → Long effect for better utilisation
• Want maximum absorption? → Liposomal Vitamin C
• Training intensely? → Long effect or liposomal Vitamin C at a dose of 200–500 mg per day
• Looking for something for children? → Drops, syrup, or chewable tablets
• Want to cover the two most common winter deficiencies at once? → Vitamin C + D3

Vitamin C is one of the most thoroughly studied micronutrients in existence – with clearly proven effects on immunity, collagen production, energy metabolism, and protection of cells against oxidative stress. Whether you are taking it preventatively over winter, supporting post-training recovery, or addressing a gap in your diet, choosing the right form makes a significant difference.

Find your Vitamin C on BodyWorld.eu based on your individual needs – classic ascorbic acid, a rosehip variant, long effect for higher doses, or liposomal form for maximum absorption. And don't forget to check out our latest offers and discounts.