Average daily recommended amounts for different ages are listed below in milligrams mg. Fruits and vegetables are the best sources of vitamin C. You can get recommended amounts of vitamin C by eating a variety of foods including the following:. The vitamin C content of food may be reduced by prolonged storage and by cooking. Steaming or microwaving may lessen cooking losses.
Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually eaten raw. Most multivitamins have vitamin C.
Vitamin C is also available alone as a dietary supplement or in combination with other nutrients. The vitamin C in dietary supplements is usually in the form of ascorbic acid, but some supplements have other forms, such as sodium ascorbate, calcium ascorbate, other mineral ascorbates, and ascorbic acid with bioflavonoids.
Research has not shown that any form of vitamin C is better than the other forms. Most people in the United States get enough vitamin C from foods and beverages. However, certain groups of people are more likely than others to have trouble getting enough vitamin C:. Vitamin C deficiency is rare in the United States and Canada. People who get little or no vitamin C below about 10 mg per day for many weeks can get scurvy. Scurvy causes fatigue, inflammation of the gums, small red or purple spots on the skin, joint pain, poor wound healing, and corkscrew hairs.
Additional signs of scurvy include depression as well as swollen, bleeding gums and loosening or loss of teeth. People with scurvy can also develop anemia. Scurvy is fatal if it is not treated. Scientists are studying vitamin C to understand how it affects health. Here are several examples of what this research has shown.
People with high intakes of vitamin C from fruits and vegetables might have a lower risk of getting many types of cancer, such as lung, breast, and colon cancer. However, taking vitamin C supplements, with or without other antioxidants, doesn't seem to protect people from getting cancer.
Perhaps the best-known and most widely promoted use of high-dose vitamin C is to prevent or treat the common cold. The bulk of the evidence shows that high-dose vitamin C will, at most, shorten a cold by one day. The recommended vitamin C dosage per day for healthy women is 75 mg per day mg per day for women who are pregnant or breastfeeding.
For adults, the tolerable upper intake level UL — the highest daily intake likely to pose no risks — is 2, mg per day. Vitamin C is water-soluble, so any excess is usually excreted in the urine rather than stored in the body. It's safe in almost any amount from foods, and supplements in recommended amounts are also regarded as safe for most people. In some people, high doses — more than, say, 2, or 3, mg per day — can cause symptoms such as diarrhea, nausea, heartburn, gastritis, fatigue, flushing, headache, and insomnia.
People with chronic liver or kidney conditions, gout, or a history of calcium-oxalate kidney stones should take no more than 1, mg a day. As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
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The limit remains the same for pregnant or breastfeeding women. Some people may have to take larger amounts of vitamin C for medical treatments. Less commonly, people may experience severe side effects from taking too much vitamin C. Long term intake above the recommended levels increases the risk of these negative effects. Doctors believe that too much vitamin C supplementation could result in a person excreting the compounds oxalate and uric acid in their urine.
These compounds could lead to kidney stone formation. The authors of a case study in the journal Kidney International reported that a woman developed kidney stones after taking 4 g or more of vitamin C each day for 4 months. However, researchers have not conducted any larger scale studies on vitamin C intake and kidney stone formation.
They do know that people who have a history of kidney stones are more likely to form them if they take large amounts of vitamin C, according to the ODS. For example, vitamin C may reduce the levels of vitamin B and copper in the body. The presence of vitamin C can also enhance iron absorption in the body, which could lead to excessively high levels. According to the Arthritis Foundation , one study found that the presence of very high vitamin C levels in the body increased the likelihood of a person developing painful bone spurs.
However, the Foundation also cited a research study that found that people with low levels of vitamin C had a higher risk of developing rheumatoid arthritis , a painful inflammatory joint condition. These findings emphasize the need for appropriate vitamin C supplementation that provides neither too much nor too little. This drug combines the vitamin niacin with the statin simvastatin Zocor , and people take it to treat high cholesterol.
If a person takes vitamin C supplements and niacin-simvastatin, they should talk to their doctor about ways to make each more effective. Doctors do not know whether vitamin C also affects the ability of other medicines similar to Zocor. If someone is at risk of a vitamin C deficiency, they can take vitamin C supplements. You should be able to get all the vitamin C you need from your daily diet. Vitamin C cannot be stored in the body, so you need it in your diet every day.
What happens if I take too much vitamin C?
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