Atlas record

Vitamin C

Vitamin C is a water-soluble vitamin needed for building connective tissue, for immunity and for iron absorption. It is found in most fresh vegetables and fruit.

TypeWater-soluble vitamin
Main roles
  • Making collagen (connective tissue)
  • Antioxidant protection
  • Increasing the absorption of plant iron
  • Supporting the working of immune cells
Sources
  • Rosehip
  • Sweet peppers
  • Citrus fruit (orange, lemon)
  • Kiwi
  • Strawberries
  • Parsley and green leafy vegetables
Deficiency noteA long-standing severe shortfall is associated with gum problems and delayed wound healing; it is rare today, and assessment belongs to a doctor.
CautionVery high-dose supplements can cause digestive complaints; a doctor should be consulted before taking them regularly.

What does it do in the body?

Vitamin C is an essential component in making collagen, the protein that holds skin and blood vessels together. As an antioxidant it also helps protect cells from the effects of free radicals, and it increases the absorption of plant-based iron. The human body can neither make nor store vitamin C, so it has to come regularly from food.

Sources and kitchen tips

Rosehip, peppers, parsley, citrus fruit, kiwi and strawberries are among the rich sources, and tomatoes and potatoes contribute to daily intake as well. Vitamin C is sensitive to heat and water: long boiling passes it into the cooking water and breaks part of it down. Cooking vegetables briefly, in little water or with steam, and preparing a salad just before it is served are practical ways of reducing the loss.

The common cold myth

Contrary to a widespread belief, the general finding of research is that vitamin C supplements do not prevent an ordinary cold in most people; some studies have observed a small shortening of how long the illness lasts. No extra benefit from high-dose supplements has been shown in someone who eats a balanced diet, and very high doses can cause digestive complaints and trouble for people prone to kidney stones. Requirements vary with age and circumstances, smoking for example; if a supplement is being considered, it is sensible to consult a doctor.

Related terms: Iron, Tomato, Apple

From the same atlas

First published: 2026-08-12Last reviewed: 2026-08-12Editorial status: working editionReport an error