What do vitamin c do

Although some epidemiological studies that follow large groups of people over time have found a protective effect of higher intakes of vitamin C from food or supplements from cardiovascular disease and certain cancers, other studies have not. Randomized controlled trials have not found a benefit of vitamin C supplements on the prevalence of cardiovascular disease or cancer.

The inconsistency of the data overall prevents the establishment of a specific vitamin C recommendation above the RDA for these conditions.

Vitamin C has also been theorized to protect from eye diseases like cataracts and macular degeneration. Human studies using vitamin C supplements have not shown a consistent benefit, though there appears to be a strong association between a high daily intake of fruit and vegetables and decreased risk of cataracts. Reviews of several studies show that megadoses greater than mg daily of supplemental vitamin C have no significant effect on the common cold, but may provide a moderate benefit in decreasing the duration and severity of colds in some groups of people.

Fruits and vegetables are the best sources of this vitamin. Vitamin C deficiency is rare in developed countries but may occur with a limited diet that provides less than 10 mg daily for one month or longer. In developed countries, situations at greatest risk for deficiency include eating a diet restricted in fruits and vegetables, smoking or long-term exposure to secondhand smoke, and drug and alcohol abuse.

The following are the most common signs of a deficiency. The contents of this website are for educational purposes and are not intended to offer personal medical advice.

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Please try again. Something went wrong on our side, please try again. Show references Vitamin C — Fact sheet for health professionals. Office of Dietary Supplements. Accessed Oct. Vitamin C — Fact sheet for consumers. Natural Medicines. Pazirandeh S, et al.

Overview of water-soluble vitamins. Quidel S, et al. What are the effects of vitamin C on the duration and severity of the common cold? Ascorbic acid oral. Ascorbic acid. The federal government's Dietary Guidelines for Americans notes that "Because foods provide an array of nutrients and other components that have benefits for health, nutritional needs should be met primarily through foods.

In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients e. For more information about building a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the U. Department of Agriculture's MyPlate.

This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice. We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice.

Updated: March 26, History of changes to this fact sheet. Find ODS on:. Strengthening Knowledge and Understanding of Dietary Supplements.

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