Last reviewed on 11 September 2026.
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Here is what an adult needs, which foods supply it, what a 500 mg tablet does once swallowed, and who genuinely needs one.
How much vitamin C do you need in a day?
Roughly 65 to 80 mg a day covers a healthy adult. The ICMR-NIN Nutrient Requirements for Indians (2020) put the recommended intake at about 80 mg for men and about 65 mg for women, with higher figures during pregnancy and more again while breastfeeding. Humans, unlike most mammals, cannot make vitamin C and keep only a modest reserve, so a steady daily supply matters far more than an occasional large dose.
What does vitamin C do in the body?
It is needed to make collagen, the protein that holds skin, gums, blood vessels, tendons and healing wounds together, which is why deficiency shows up first in those tissues. It also acts as an antioxidant in the watery parts of cells, helps the gut take up iron from plant foods, and is used in making carnitine and some brain chemicals. The tablet uses printed on labels, often searched for in Hindi, mostly restate these functions rather than proving that extra tablets do more.
Which Indian foods are richest in vitamin C?
Amla and guava lead the list. Indian food composition data put amla at several hundred milligrams per 100 g, though published values swing widely with variety, ripeness and how long the fruit has been stored. Guava carries about 200 mg per 100 g, around four times as much as an orange. Green capsicum gives roughly 80 to 120 mg per 100 g, and red or yellow capsicum more. Papaya, oranges, mosambi, cabbage, cauliflower and leafy greens such as drumstick leaves and amaranth are good contributors. Tomato offers a smaller 15 to 25 mg or so, and sprouting brings a little vitamin C into pulses that have almost none when dry.
| Food | Roughly per 100 g |
|---|---|
| Amla | several hundred mg, though published values swing widely |
| Guava | about 200 mg, around four times an orange |
| Green capsicum | roughly 80 to 120 mg, and more in red or yellow |
| Tomato | about 15 to 25 mg |
| Apple | roughly 5 mg, by USDA figures |
An adult needs about 80 mg a day for men and about 65 mg for women, so one guava clears it.
Can one guava or one amla really cover a whole day?
Yes, for most adults a single fruit is enough. A medium guava of 100 to 150 g supplies something in the region of 200 to 300 mg, three times an adult's requirement or more. One fresh amla, even a small one, can match or exceed the daily figure, depending on its size and freshness. The apple is the surprise in the other direction. It has real merits, which the post on calories in one apple covers, but vitamin C is not one of them: USDA figures put it at roughly 5 mg per 100 g.
Does cooking destroy vitamin C?
Yes, often a quarter to a half of it or more, depending on the method. Vitamin C dissolves in water and breaks down with heat, air and alkali, so boiling greens and throwing the water away, simmering a sabzi for a long time or adding a pinch of baking soda to keep palak bright all strip it out. Steaming, quick stir-frying and short pressure cooking lose less. The simplest fix is to eat some produce raw every day: fruit, salad, a fresh chutney. Processed amla products such as murabba, candy and powder generally keep much less than the fresh fruit, and the first two add a good deal of sugar.
What happens to a 500 mg vitamin C tablet in your body?
Much of it is passed out rather than used. Careful studies in healthy volunteers at the US National Institutes of Health found that blood and white-cell concentrations plateau at intakes of around 200 mg a day. Above that, the gut absorbs a smaller share of each dose and the kidneys excrete what the tissues cannot hold; at 1 g or more, less than half is absorbed. So for someone already eating fruit and vegetables, a 500 mg tablet mainly raises the vitamin C in their urine. It is not dangerous at that dose for most people, but it is not extra protection either.
Do vitamin C tablets prevent colds?
No, not in the general population. A Cochrane review by Hemilä and Chalker (2013), which pooled trials using at least 200 mg a day, found that regular supplementation did not reduce how often ordinary people caught colds. It did shorten colds modestly, by about 8 per cent in adults and 14 per cent in children, which works out to around half a day on an adult's week-long cold. The exception was people under heavy physical stress, such as marathon runners and soldiers in subarctic conditions, whose risk roughly halved. Starting tablets once symptoms had begun showed no consistent benefit. What does support immune health is covered in the post on an immunity-boosting Indian diet.
Can too much vitamin C be harmful?
Yes, at high doses. The tolerable upper intake level, set in the US by the Institute of Medicine, is 2 g (2,000 mg) a day for adults. Beyond that, unabsorbed vitamin C draws water into the gut and causes diarrhoea, nausea and cramps. There is also a kidney stone concern, because the body turns some vitamin C into oxalate, a component of the most common stones. A large Swedish study of men found that those taking vitamin C supplements developed kidney stones at roughly twice the rate of non-users. Anyone with a history of stones, kidney disease or an iron overload disorder should clear high-dose vitamin C with their doctor first.
Who might actually need a vitamin C tablet?
A fairly small group. Smokers need more, because smoking uses the vitamin up faster, and US guidance adds 35 mg a day for them; an extra piece of fruit meets that more cheaply than a tablet. People whose diets contain almost no fresh fruit or vegetables, such as some older adults living alone, heavy drinkers and people on very limited diets, may benefit. So may people on dialysis, which removes water-soluble vitamins, and those recovering from surgery or serious illness when their doctor advises it. Even then the need is usually modest, and the 500 mg and 1,000 mg strengths are more than it calls for.
Should you take vitamin C with iron tablets?
Sometimes, if your doctor suggests it. Vitamin C helps the gut absorb non-haem iron, the form in plant foods and most iron tablets, and some iron preparations include it for that reason. The benefit of adding a separate vitamin C tablet is less certain: at least one trial, published in 2020, found oral iron worked about as well without it. At meals, a squeeze of lemon on dal, amla chutney beside a millet roti or guava after lunch helps, while tea or coffee with the meal works against it. The fuller list of iron sources sits in the post on iron-rich Indian foods.
What disease does vitamin C deficiency cause?
Scurvy. It develops after a month or more of eating less than about 10 mg a day, and it starts vaguely, with tiredness, irritability and aching legs and joints. Later come swollen, bleeding gums, bruising from light knocks, tiny red-blue spots around hair follicles, coiled hairs, slow wound healing and anaemia. Young children may refuse to walk because their legs hurt. People searching in Hindi ask vitamin C ki kami se kaun sa rog hota hai, and the answer is the same. Scurvy still turns up in India, usually in people on extremely narrow diets, including some children who accept very few foods. Treatment works quickly once it is diagnosed.
Are chewable 500 mg vitamin C tablets a good idea?
Not as a daily habit. Most chewables are sweetened with sugar or a sugar alcohol and flavoured to taste like sweets, which is exactly how children come to treat them. Chewing an acidic tablet every day also bathes the teeth in acid, and dentists have reported enamel erosion from the practice. If a doctor has advised a supplement, a swallowed tablet of modest strength does the same job without these drawbacks.
How do you cover vitamin C in an ordinary Indian day?
Without much effort. A guava, an orange or a few slices of papaya at tea time, a raw kachumber or sprouts with lunch, lemon over dal or poha, and a quick-cooked capsicum or cabbage sabzi at dinner easily clear 100 mg. A bowl of fruit chaat with guava and orange in it does the job on its own. The vitamin C in cut fruit fades as it sits, so cut it close to eating.
Covering the day from food alone
None of this needs planning so much as placing something fresh in each part of the day.
Something raw with lunch
A kachumber, a few sprouts or a fresh chutney beside the meal, since raw produce keeps what cooking takes away.
Lemon where it fits
Squeezed over dal or poha it costs nothing, and it helps the gut take up iron from the same plate.
Fruit at tea time
A guava, an orange or a few slices of papaya. A bowl of fruit chaat with guava and orange in it does the day's work on its own.
A quick-cooked sabzi at dinner
Capsicum or cabbage cooked briefly rather than simmered, which keeps far more of the vitamin than a long-cooked dish.
Cut close to eating
Vitamin C in cut fruit fades as it sits, so a plate cut in the morning for the evening loses some of the point.
Learning to answer supplement questions properly
Anyone who fields supplement questions from family or clients meets the 500 mg question weekly. NNWA's Dietary Supplements & Nutraceuticals course covers vitamins and minerals, reading supplement labels, safety and interactions, and evidence versus hype, over four to six weeks at an intermediate level. The fee is 11,999 rupees, reduced from 17,999, with EMI from 1,000 rupees a month, and it carries an NNWA certificate.
The short answer
Most people meet their vitamin C needs from food, and one guava or amla a day is enough on its own. Tablets add little for well-fed adults, do not prevent colds, and at very high doses can upset the stomach or feed kidney stones. They make sense for smokers, very poor diets and specific medical advice, in modest strengths.