Vitamin C (Ascorbic acid)

Description Vitamin C, also known as ascorbic acid, is a water soluble vitamin.
Function/ Used for Vitamin C acts as an anti-oxidant, neutralising free radicals to protect cells.

Vitamin C is involved in the synthesis of collagen and other constituents of bone, teeth and capillaries. It aids wound healing.

It is also necessary for the function of several enzymes and it increases the absorption of iron in the gut.

Vitamin C may have a role in protecting against the common cold as well as conditions such as cancer, cardiovascular disease, cataracts, diabetes and Parkinson’s disease.

It also helps contribute to normal energy metabolism and nervous system function and reduces tiredness and fatigue.

Intake Recommended intake

EU NRV: 80mg


Chief Medical Officer recommendations are that all children aged six months to five years should take a daily supplement containing vitamins A, C and D.


UK average daily intake

Requirements vary depending on age and gender. The UK National Diet and Nutrition Survey lists up-to-date intake requirements and average intakes1.

As a supplement Available as a single supplement. Also commonly available as part of a multivitamin and mineral formula.

Different multivitamin and minerals products will vary in the percentage NRVs they include. People should always check the label for information about a specific product.

Found in (dietary sources) Foods of plant origin, particularly citrus and soft fruits (such as oranges, strawberries, kiwi, blackcurrant, guava) and vegetables (such as kale, broccoli, brussels sprouts, peppers, potatoes, tomatoes) are major sources of vitamin C.

Vitamin C is readily lost during storage and cooking.

Deficiency Vitamin C deficiency may lead to scurvy. Early symptoms in adults include fatigue, weakness, aching joints and muscles. In later stages, symptoms of scurvy include anaemia, swollen and bleeding gums and delayed wound healing. In children, bones, teeth and blood vessels develop abnormally and growth is affected.

Low levels of vitamin C have been associated with poor wound healing and ulceration.3

Precautions and contraindications Vitamin C supplements should be used with caution by people with diabetes and by sufferers of disorders of iron metabolism or storage e.g. haemochromatosis and thalasaemia.3


Safe Upper Level: 1000mg/day2

Use in pregnancy and breastfeeding Long term intakes of large doses of vitamin C in pregnancy may result in increased requirements for the vitamin and scurvy in the offspring.
Interactions e.g. with other medications Vitamin C has an impact on how drugs are metabolized in the liver. Large doses of vitamin C may affect how drugs are absorbed and utilized.

Prolonged use of oral contraceptives may reduce blood levels of vitamin C.

Taking aspirin may lead to increased loss of vitamin C.

Vitamin C may reduce the activity of the anti-coagulant warfarin (a blood-thinner). People taking warfarin should consult with their doctor before taking vitamin C supplements.3,4

Adverse effects There is no evidence of serious health risks associated with high doses of vitamin C but daily doses over 1g may lead to diarrhoea and gastric discomfort.

Doses of 2g and above may result in increased risk of kidney stones.

  2. Expert Group on Vitamins and Minerals, 2003.
  3. Mason, P. Dietary Supplements. Pharmaceutical Press, London, 2001.
  4. Gaby, A. R. A-Z Guide to Drug-Herb-Vitamin Interactions. HealthNotes 2006.