The standard daily amount depends on your age and sex

The Recommended Dietary Allowance (RDA) for vitamin C is set by the National Institutes of Health and varies by age and sex. For adult men, the RDA is 90 milligrams per day. For adult women, it is 75 milligrams per day. Pregnant women need 85 milligrams daily, and those who are breastfeeding need 120 milligrams daily. Smokers of any sex should add an extra 35 milligrams to their daily amount.

Most vitamin C tablets sold over the counter contain between 250 and 1,000 milligrams per tablet. This means a single tablet typically exceeds the RDA by a significant margin. Your body absorbs only what it needs and excretes excess vitamin C through urine, so taking more than the RDA does not automatically harm you—but it also does not provide additional benefit for most people.

Children have lower RDA amounts: infants under 6 months need 40 milligrams daily, children ages 1 to 3 need 15 milligrams, ages 4 to 8 need 25 milligrams, and ages 9 to 13 need 45 milligrams. A standard children's vitamin C tablet is usually 50 to 250 milligrams.

Key Takeaways

  • Adult men need 90 milligrams of vitamin C daily, and adult women need 75 milligrams, according to the National Institutes of Health.
  • Most over-the-counter vitamin C tablets contain 250 to 1,000 milligrams, which is more than the daily recommendation for most people.
  • Your body uses what it needs and removes excess vitamin C through urine, so taking a standard tablet once daily will not cause harm from overdose.
  • Smokers should consume an additional 35 milligrams daily beyond the standard RDA.
  • Children require less vitamin C than adults, ranging from 15 to 45 milligrams daily depending on age.

What happens if you take more than the RDA

Vitamin C is water-soluble, meaning your body does not store it the way it stores fat-soluble vitamins like A, D, E, and K. When you consume more vitamin C than your body can use, the excess leaves through your urine. This is why taking a 500-milligram tablet when you only need 90 milligrams does not accumulate in your system.

However, very high intakes—generally above 2,000 milligrams per day—can cause side effects in some people. These include stomach upset, nausea, diarrhea, and kidney stones in those with a history of kidney problems. The Tolerable Upper Intake Level (UL) set by the National Institutes of Health is 2,000 milligrams daily for adults. This is the highest amount unlikely to cause harm in the general population.

If you are taking a single standard tablet of 250 to 1,000 milligrams once daily, you are well below this upper limit and unlikely to experience side effects from the vitamin C itself.

When you might need more than the RDA

Most people who eat a diet containing fruits and vegetables—especially citrus, berries, peppers, and leafy greens—meet the RDA through food alone. If you eat these foods regularly, a tablet may be unnecessary. However, some situations may warrant higher intake.

People recovering from surgery, burns, or serious illness sometimes benefit from additional vitamin C because the body uses more during healing. Those with certain chronic conditions, people taking specific medications, or those with absorption problems may also have higher needs. If you fall into one of these categories, discuss your vitamin C intake with your doctor or a registered dietitian, who can recommend an amount tailored to your situation.

Athletes sometimes take higher doses based on the theory that vitamin C supports immune function during intense training, though research on this is mixed. Again, a conversation with a healthcare provider can help you decide whether extra vitamin C makes sense for your circumstances.

How to read the label on your tablet

Vitamin C tablets list the amount of vitamin C per tablet in milligrams, usually near the top of the nutrition facts label. Look for the line that says "Vitamin C" followed by a number and "mg." This is the total amount of the nutrient in that single tablet.

Below that, you may see a percentage labeled "%DV" or "% Daily Value." This percentage is based on a 90-milligram daily value for adults. If a tablet contains 500 milligrams of vitamin C, the label will show this as 556% DV (because 500 divided by 90 equals about 5.56). This high percentage can look alarming, but it straightforward reflects that the tablet contains much more than the minimum daily need.

Some tablets also list the form of vitamin C used—such as ascorbic acid, sodium ascorbate, or calcium ascorbate. These forms are absorbed similarly by the body, so the choice between them is usually based on personal tolerance or cost rather than effectiveness.

Timing and frequency of your dose

You can take a vitamin C tablet at any time of day with or without food. Unlike some vitamins, vitamin C does not require fat for absorption, though taking it with a meal may reduce stomach upset if you are sensitive to it. If you are taking a single tablet daily, consistency matters more than the exact time—taking it at the same time each day straightforward makes it easier to remember.

If your tablet is very large or you have a sensitive stomach, you can split the dose. For example, if you take a 500-milligram tablet, you could take half in the morning and half in the evening. This approach may reduce the chance of stomach discomfort, though most people tolerate a single dose without issue.

Do not take vitamin C tablets with certain medications without checking with your doctor first. Vitamin C can interact with blood thinners, chemotherapy drugs, and some other medications. If you take any prescription medications, mention your vitamin C tablet to your healthcare provider.

Food sources versus tablets

Meeting your vitamin C needs through food is generally preferred over tablets because whole foods contain other nutrients and compounds that work together. One medium orange provides about 70 milligrams of vitamin C. One cup of raw bell pepper provides about 95 milligrams. One cup of strawberries provides about 85 milligrams. Kiwi, broccoli, and Brussels sprouts are also excellent sources.

If you eat a variety of fruits and vegetables daily, you likely meet the RDA without a tablet. A tablet is most useful for people who do not eat enough of these foods, those with absorption issues, or those whose doctor has recommended additional vitamin C for a specific reason.

Vitamin C from food is not "better" than from tablets in the sense that your body absorbs and uses it the same way. The advantage of food is the additional fiber, minerals, and phytonutrients that come along with it. If you prefer a tablet for convenience, taking one standard dose daily is a straightforward way to meet the RDA.

Frequently Asked Questions

Can I take a vitamin C tablet every day?

Yes. Taking a standard 250 to 1,000 milligram tablet once daily is safe for most adults and will not cause harm. You will not overdose on vitamin C because excess amounts leave your body through urine. If you have kidney disease or a history of kidney stones, discuss daily vitamin C use with your doctor first.

Is it better to take one large tablet or split it into smaller doses?

Your body absorbs vitamin C the same way regardless of whether you take it all at once or in divided doses. Choose based on what works for your stomach and schedule. Some people find a single dose easier to remember; others prefer splitting it to reduce stomach upset.

What if I accidentally take two tablets in one day?

Taking two standard tablets in one day will not harm you. The excess vitamin C will straightforward be removed through your urine. If you make this a habit, you would be consuming more than the upper limit, so try to stick to one tablet daily—but a single extra dose is not dangerous.

Do I need a vitamin C tablet if I eat plenty of fruit?

Probably not. If you eat citrus, berries, peppers, or other vitamin C-rich foods regularly, you likely meet the RDA through diet alone. A tablet is most useful for people whose diet is low in these foods or those with specific health reasons to take extra vitamin C.

Can children take adult-strength vitamin C tablets?

Adult-strength tablets (250 to 1,000 milligrams) are too much for most children. Children have lower RDA amounts—for example, a 10-year-old needs only 45 milligrams daily. Look for children's vitamin C tablets, which typically contain 50 to 250 milligrams, or ask your child's doctor what dose is appropriate.