Vitamin C

What is Vitamin C?

Vitamin C (ascorbic acid) is a water-soluble vitamin. People cannot make it, so it must come from food.^[1]

It is an antioxidant, which means it helps protect cells from some kinds of damage.^[1]

Its role in the body

• Needed to make collagen, a protein that holds together skin, gums, blood vessels and wounds as they heal.^[1]
• Helps the body absorb non-haem iron, the type of iron found in plant foods.^[1]
• Supports the immune system.^[1]

Important food sources

• Amla (Indian gooseberry)Widely regarded as a very rich source; we have not yet verified a specific value.
• GuavaA rich, affordable source.
• Oranges, mosambi, lemons and other citrus fruits
• Papaya, mango, pineapple and strawberries
• Capsicum (bell peppers), tomatoes, cabbage, cauliflower and green leafy vegetables
• TipLong cooking and storage reduce vitamin C, so raw or lightly cooked foods keep more of it.

Recommended dietary intake

Signs sometimes associated with low levels

• Severe, long-term lack causes scurvy, which is rare. Signs include tiny red or purple spots on the skin, easy bruising, swollen or bleeding gums, joint pain, slow wound healing and corkscrew-shaped hairs.^[1]
• Scurvy can appear after about a month of eating very little vitamin C (under about 10 mg a day). It can be serious if not treated.^[1]

Why symptoms alone cannot confirm a deficiency

Signs like tiredness, weakness, hair fall or low mood are very common and have many possible causes, such as poor sleep, stress, infections, thyroid problems or other illnesses.

The same sign can come from several different nutrients, or from no nutrient problem at all.

Only a qualified clinician, using your history, an examination and, when needed, lab tests, can say whether a deficiency is present. This app cannot diagnose a deficiency from symptoms or from BMI.

Bleeding gums and bruising are much more often due to gum disease, injury, medicines or blood disorders than to low vitamin C.

Tests a clinician might consider

• Plasma vitamin C level, although it mostly reflects recent intake.^[1]
• Diagnosis of scurvy also relies on the person’s diet history and examination.^[1]

Who is more likely to have low intake

• People who smoke and people exposed to second-hand smoke.^[1]
• People who eat a very limited variety of foods, with few fruits and vegetables.^[1]
• People with conditions that reduce absorption, and some people with long-term illnesses such as some cancers or kidney disease on dialysis.^[1]
• Infants fed evaporated or boiled milk instead of breast milk or formula.^[1]

Potential benefits and quality of evidence

• Vitamin C is essential for collagen and wound healing, and it improves absorption of iron from plant foods.^[1] Established
• Regular vitamin C does not prevent colds in most people, but may slightly shorten them. It may lower the chance of colds in people under heavy physical stress, such as intense exercise or cold environments.^[1] Moderate evidence
• Evidence that vitamin C supplements prevent cancer or heart disease is inconsistent.^[1] Not enough evidence
• Vitamin C alone has not been shown to change the risk of developing cataracts or age-related macular degeneration.^[1] Limited evidence

Side effects

• High-dose supplements can cause diarrhoea, nausea, stomach cramps and other stomach upset.^[1]

Risks of too much

• Vitamin C has low toxicity, but very high intakes may raise the risk of kidney stones in some people.^[1]
• It increases iron absorption, which can be a concern for people with hereditary haemochromatosis (iron overload).^[1]

Medicine and supplement interactions

• Cancer chemotherapy and radiation therapy: Antioxidant supplements might reduce or otherwise change the effect of some cancer treatments; this is debated. People having cancer treatment should ask their oncology team before use.^[1]
• Statins (when taken with niacin): Antioxidant supplements including vitamin C might blunt the rise in HDL ("good") cholesterol from combined statin–niacin treatment.^[1]

Never start, stop or change a prescribed medicine because of this list — talk to your doctor or pharmacist.

Pregnancy and breastfeeding

• Needs rise in pregnancy and breastfeeding. Food sources are the preferred way to meet them. Use supplements only as advised by your doctor; the same upper limit applies.^[1]

Kidney and liver cautions

• People with a history of kidney stones or with kidney disease should talk to their doctor before taking vitamin C supplements, because high doses may raise kidney-stone risk.^[1]

Upper intake limits

When to talk to a professional

Talk to a doctor or registered dietitian before starting a supplement, especially if you are pregnant or breastfeeding, have a long-term illness, or take any regular medicines.

Do not start, stop or change a prescribed medicine because of anything you read here.

Supplements sold without a prescription are not automatically safe. Doses, quality and interactions still matter.

Seek medical care promptly if you have severe, sudden or worsening symptoms.

Still being verified

• ICMR-NIN 2020 values for pregnancy/lactation and Tolerable Upper Limit not verified; not stated.
• Vitamin C content of amla not yet verified from a permitted source.

References

1. NIH Office of Dietary Supplements. Vitamin C — Fact Sheet for Health Professionals (opens in a new tab) (2025-07-31). Accessed 9 Oct 2026.
2. ICMR-National Institute of Nutrition (India). A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR), ICMR-NIN, 2020 (opens in a new tab). Accessed 9 Oct 2026.

Sources checked: 9 Oct 2026