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Vitamin C Requirements and Dietary Sources

Vitamin Guide


Updated July 04, 2014

Orange Juice

One glass of orange juice will give you a whole day's worth of vitamin C.

Steve Woods

Vitamin C, also known as ascorbic acid, is a member of the water-soluble family of vitamins. It's required for normal growth and maintenance of most of the tissues of your body, including collagen, which is needed for healthy connective tissue and for wound healing.

Vitamin C also helps your bones and teeth stay strong. It's also necessary to make certain neurotransmitters and for protein metabolism. Your immune system relies on vitamin C for normal function too. 

Plus there's an added bonus for vegetarians. Eating foods rich in vitamin C will help your body absorb more iron from plant sources such as spinach, nuts and seeds.

The Institute of Medicine of the National Academy has determined the dietary reference intakes (DRI) for vitamin C. It's based on the daily nutritional needs of an average healthy person. If you have any medical issues, you should speak to your health care provider about your vitamin C requirements.

Dietary Reference Intakes


1 to 3 years: 15 milligrams per day
4 to 8 years: 25 milligrams per day
9 to 13 years: 45 milligrams per day
14 to 18 years: 75 milligrams per day
19+ years: 90 milligrams per day


1 to 3 years: 15 milligrams per day
4 to 8 years: 25 milligrams per day
9 to 13 years: 45 milligrams per day
14 to 18 years: 65 milligrams per day
19+ years: 75 milligrams per day

Vitamin C is found naturally in fruits and vegetables, especially citrus fruits, strawberries, peppers, tomatoes, broccoli and potatoes. People who don't eat enough fruits and vegetables are at risk for developing a deficiency.

A deficiency can lead to dry hair, gingivitis, slow wound healing, a weakened immune system, anemia and nosebleeds.

Smoking and certain serious chronic diseases may increase your need or contribute to a deficiency. 

Scurvy can occur as the result long-standing vitamin C deficiency. The symptoms include weakness, anemia, gum disease, and skin hemorrhages.

Vitamin C Supplements

Vitamin C is an antioxidant and it's been recommended as a supplement for relief of colds and flu, and as an alternative treatment for some forms of cancer. However, research hasn't provided sufficient evidence for these recommendations. Although some studies have indicated that people with some types of cancer have lower blood levels of vitamin C than the general public, there's no evidence that taking vitamin C supplements reduces your risk of cancer.

You can probably skip the supplemental form -- you're better off eating more fruits and vegetables -- they're rich in vitamin C and they have other beneficial compounds you won't find in a typical dietary supplement.

But, if you really think you need the supplements, avoid megadosing vitamin C. Taking large amounts of supplemental vitamin C may result in diarrhea or loose stools. The Institute of Medicine established 1,800 to 2,000 milligrams per day as the upper tolerable intake level.


Institute of Medicine of the National Academies. "Daily Reference Intakes: Vitamins." Accessed July 1, 2014. http://iom.edu/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Vitamins.pdf

MedlinePlus.com. "Scurvy." Accessed May 14, 2014. http://www.nlm.nih.gov/medlineplus/ency/article/000355.htm.

National Institutes of Health, Office of Dietary Supplements. "Vitamin C Fact Sheet for Health Professionals." Accessed May 14, 2104. http://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/.

Otten JJ, Hellwig JP, Meyers LD. "Dietary Reference Intakes: The Essential Guide to Nutrient Requirements." Institutes of Medicine, 2006.


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