Vitamin C
What it is and what it does
- Vitamin C, also called ascorbic acid, is a water-soluble nutrient found in some foods. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Consumers (updated 2021-03-22))
- Unlike most animals, humans cannot make vitamin C in the body, so it is an essential part of the diet. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- Vitamin C is needed to make collagen, L-carnitine and certain neurotransmitters, and is involved in protein metabolism. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- ICMR-NIN describes vitamin C as an essential nutrient needed for bones and teeth. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- In the body, vitamin C acts as an antioxidant. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Consumers (updated 2021-03-22))
- Vitamin C helps regenerate other antioxidants in the body, including vitamin E (alpha-tocopherol). (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- Vitamin C improves the absorption of iron from plant foods. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Consumers (updated 2021-03-22))
Why it matters
- Too little vitamin C causes scurvy, marked by tiredness, weakness of connective tissue throughout the body, and fragile capillaries. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- ICMR-NIN: vitamin C deficiency shows as weakness, bleeding gums and defective bone growth. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Signs of deficiency can appear within a month of little or no vitamin C intake (below about 10 mg a day). (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- People who smoke need 35 mg more vitamin C a day than people who do not smoke. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- Too much vitamin C can cause diarrhoea, nausea and stomach cramps. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Consumers (updated 2021-03-22))
General information, not medical advice — for your own needs, ask a doctor or dietitian.
How much is needed
| Who | Amount | What the figure is | Whose figure |
|---|---|---|---|
| Adult man (all activity levels) | 80 mg/day | RDA | ICMR-NIN 2020 |
| Adult woman (all activity levels) | 65 mg/day | RDA | ICMR-NIN 2020 |
| Pregnant woman (additional to the non-pregnant value) | +15 mg/day | RDA | ICMR-NIN 2020 |
| Lactating woman (additional) | +50 mg/day | RDA | ICMR-NIN 2020 |
| Adults incl. pregnancy and lactation | 2000 mg/day | TUL (tolerable upper limit) | ICMR-NIN 2020 |
| Daily diet (guidance) | at least 20 mg ascorbic acid per 1000 kcal | Diet density recommendation (for iron absorption) | ICMR-NIN 2020 |
| Adult men, 19+ years (US) | 90 mg/day | RDA | US NASEM via NIH ODS (not an Indian value) |
| Adult women, 19+ years (US) | 75 mg/day | RDA | US NASEM via NIH ODS (not an Indian value) |
| Pregnancy, 19+ years (US) | 85 mg/day | RDA | US NASEM via NIH ODS (not an Indian value) |
| Adults 19+ years, men and women incl. pregnancy and lactation (US) | 2,000 mg/day | UL (tolerable upper intake level) | US NASEM via NIH ODS (not an Indian value) |
India’s own figure (ICMR-NIN 2020) comes first. Figures from other bodies are shown only where they help, and say whose they are.
Sources: ICMR-NIN Expert Group. Short Report of Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements - 2020; NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31)
Absorption and food
- ICMR-NIN recommends at least 20 mg of vitamin C (ascorbic acid) per 1000 kcal in the daily diet for better iron absorption. (ICMR-NIN Expert Group. Short Report of Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements - 2020)
- About 70-90% of vitamin C is absorbed at moderate intakes of 30-180 mg a day. (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- When vegetables become dry and stale, are cut and left exposed to air, or are cooked, most of their vitamin C is destroyed. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Vitamin C (like the B-complex vitamins) may be lost if the water used for boiling is thrown away. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Vitamin C is found in fresh citrus fruits, guava, amla and some vegetables such as tomatoes. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Grains do not naturally contain vitamin C (it is added to some fortified breakfast cereals). (NIH Office of Dietary Supplements. Vitamin C Fact Sheet for Health Professionals (updated 2025-07-31))
- ICMR-NIN food-group averages per 100 g raw weight: green leafy vegetables 45.6 mg, fruits 36.7 mg, other vegetables 23.6 mg, roots and tubers 12.1 mg, milk 3.3 mg, milk products 1.5 mg and nuts 0.4 mg vitamin C; cereals, millets and pulses 0 mg. Group averages only. (ICMR-NIN. Dietary Guidelines for Indians 2024)