What it is used for
- Preventing and treating vitamin C deficiency (scurvy)
- Supporting immune function and wound healing
- Helping the body absorb iron from plant sources
- Supporting people with diets low in fruit and vegetables
How it works
Vitamin C is an antioxidant the body needs to make collagen for skin, blood vessels and connective tissue, to support the immune system, and to improve absorption of iron. The body cannot make or store much of it, so a regular dietary supply is needed.
How it is taken
Available as tablets, chewable tablets, effervescent tablets, capsules and liquid. It can be taken with or without food, often with water. Take it exactly as your doctor, pharmacist or the label directs, and avoid routinely taking very large amounts.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Usually well tolerated
- Stomach upset, heartburn or diarrhoea with high doses
- Headache (uncommon)
Serious effects — get help
- Kidney stones with very high long-term doses in susceptible people
- Signs of an allergic reaction (rare)
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Iron supplements, where vitamin C can increase iron absorption (sometimes used on purpose)
- High doses may affect some lab tests and certain medicines
- Caution in people with iron-overload conditions
Who should take care
- Tell your clinician if you have kidney problems, kidney stones, or an iron-overload condition before taking high doses
- Very large doses offer no proven extra benefit and can cause side effects
- Discuss high-dose use in pregnancy and breastfeeding with your clinician
- People with G6PD deficiency should avoid very high doses