In brief
A water-soluble vitamin that acts as an antioxidant, helps the immune system work properly and is needed to make collagen.
- Vitamin C improves the absorption of iron from plant-based foods.
- For most people, vitamin C supplements do not reduce the risk of catching a cold.
- Too much vitamin C can cause diarrhoea, nausea and stomach cramps.
How it works
Your body needs vitamin C to make collagen, a protein needed for wounds to heal. It also improves the absorption of iron from plant foods. Getting little or no vitamin C for many weeks causes scurvy, with swollen, bleeding gums and poor wound healing.
Fruit and vegetables supply it, including citrus fruit, red and green capsicum, kiwifruit, broccoli, strawberries and tomatoes. People who smoke need 35 mg more vitamin C a day than people who do not.
Food sources
- Citrus fruit
- Red and green capsicum
- Kiwifruit
- Broccoli
- Strawberries
- Tomatoes
From the AskBioMap food guide:
Connections
5 connections on the map. Select a topic to read its page.
Vitamin C supports
Vitamin C improves the absorption of iron from plant-based foods.
Sources: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers; healthdirect Australia, Foods high in iron
Vitamin C helps the immune system work properly to protect the body from disease.
Source: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers
Vitamin C is affected by
People who smoke need 35 mg more vitamin C a day, because smoke raises the vitamin C the body needs to repair damage from free radicals.
Source: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers
Vitamin C can lower
Vitamin C acts as an antioxidant in the body.
Source: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers
Vitamin C is needed for
Your body needs vitamin C to make collagen, a protein needed for wounds to heal.
Source: NIH Office of Dietary Supplements, Vitamin C fact sheet for consumers
Sources
Each connection above names its own source. See every source AskBioMap uses.
Summarised from the NIH Office of Dietary Supplements. Sources read on 13 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.