Vitamin C
kwas askorbinowy · last AI check: 2026-07-19
In short
Water-soluble, found in vegetables and fruit. The body doesn't store it for long.
What it does in the body
The sentences below are officially authorised EU health claims.
Vitamin C contributes to the normal function of the immune system EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 134, 4321 · EFSA opinion: 2009;7(9):1226; 2010;8(10):1815
Condition of use on a product: The product is at least a source of Vitamin C.
Vitamin C increases iron absorption EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 132, 147 · EFSA opinion: 2009;7(9):1226
Condition of use on a product: The product is at least a source of Vitamin C.
Vitamin C contributes to the reduction of tiredness and fatigue EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 139, 2622 · EFSA opinion: 2010;8(10):1815
Condition of use on a product: The product is at least a source of Vitamin C.
Vitamin C contributes to normal collagen formation for the normal function of skin EU health claim
Commission Regulation (EU) No 432/2012 of 16 May 2012, Annex — list of permitted health claims · register entry: 131, 137, 149 · EFSA opinion: 2009;7(9):1226
Condition of use on a product: The product is at least a source of Vitamin C.
How much you need
| Country / organisation | Group | Value | Type |
|---|---|---|---|
| FAO | adult men | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. | |
| Philippines | adult men | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. | |
| India | adult men | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| Singapore | adult men | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| Switzerland | adult men | RDA Recommended daily allowance — covers the needs of almost all healthy people in a group. | |
| United Kingdom | adults | RNI Reference nutrient intake — the RDA equivalent in WHO/FAO, UK and Philippine terminology. |
Reference values from different countries are not directly comparable — they differ in definition and age group. How to read reference values →
Every value states its source — click it to see the document, location and link.Data and content are prepared and cross-checked against source documents by several independent AI models. They have not been audited by a human editor.Before citing a value, check it in the source document — verification is automated (AI), not editorial.
Worth knowing
Humans are among the few mammals unable to produce vitamin C themselves — over the course of evolution we lost a functioning gene for one of the enzymes needed for its synthesis. Most animals make it on their own and don't need to eat it; we do.
It's lost during storage and cooking
Vitamin C is both water-soluble and sensitive to heat, light and oxygen. It is the least stable nutrient on this site: the content in a vegetable can drop markedly during prolonged storage, and boiling in a large amount of water followed by draining it removes part of the vitamin along with the cooking liquid. Steaming and brief cooking preserve more of it — which is why the figures in food-composition tables usually refer to the raw product and don't translate directly to what ends up on the plate.
It's also worth correcting a common misconception: citrus fruit isn't the richest source of vitamin C. Peppers, parsley, blackcurrants or broccoli contain more of it.
The question of megadoses
Because vitamin C is water-soluble, any excess is excreted in urine, and absorption from the digestive tract falls as the dose rises. In practice this means that above a certain level the body simply doesn't take in any more — and very large doses are sometimes poorly tolerated by the digestive tract and can increase the risk of oxalate stones in predisposed individuals.
The authorised health claims for vitamin C can be found above, worded as in the EU register. Notice how they are phrased: they speak of a contribution to the normal function of the immune system, not of an effect on the course of infections. The widespread belief that vitamin C affects the common cold goes beyond what the register permits — and that is precisely why you won't find it on this site in any form.
Where to find it
peppers · parsley · citrus fruit · currants
This material is for information and education. It does not replace advice from a doctor or dietitian. For health matters, consult a qualified medical professional.