Nutrition 101: Vitamin C

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin, meaning that your body doesn’t store it. It is found in high amounts in many fruits and vegetables. Scurvy (Vitamin C deficiency) was first discovered in British sailors who were not consuming many foods that contained Vitamin C. From then on they carried Vitamin C–packed limes on their voyages.

Recommended Intakes

The Dietary Reference Intakes (DRI) for Vitamin C are shown below:

People who smoke and those who are exposed to secondhand smoke need 35 mg more Vitamin C per day than nonsmokers. Cigarette smoke increases the amount of Vitamin C that the body needs to repair damage caused by free radicals.

What Does Vitami​n C Do?

Vitamin C has a very important protective effect on the body. Like many other plant-based nutrients, including Vitamin E and beta-carotene, Vitamin C is an antioxidant. Antioxidants block some of the damage caused by free radicals, substances that damage DNA, the body’s genetic material. Over time, the accumulation of free radicals may contribute to the aging process and the development of a number of health conditions such as cancer, heart disease, arthritis, and cataracts.

Vitamin C also assists in the formation of collagen, a protein which is important for the health of blood vessels and gums, development of bones and teeth, and wound healing. In addition, Vitamin C improves the absorption of iron from plant-based foods and helps the immune system work properly to protect the body from disease.

Vitamin C deficiency is rare in North America. People who get little or no Vitamin C for many weeks can develop scurvy. Scurvy causes fatigue, depression, swollen and/or bleeding gums, loosening or loss of teeth, small red or purple spots on the skin, joint pain, poor wound healing, corkscrew hairs, and anemia. Scurvy is fatal if it is not treated.

Taking too much Vitamin C is also rare. When it occurs, it can lead to diarrhea, nausea, and stomach cramps. In people with a condition called hemochromatosis, which causes the body to store too much iron, high doses of Vitamin C could worsen iron overload and lead to the damage of body tissues.

Top Vitamin C–Rich Foods

Vegetables and fruit are the best sources of Vitamin C.

Nutrition Facts Label and the % Daily Value

In the United States: The daily value (DV) for Vitamin C is 60 mg, which is lower than the DRI for adults. The number you see on the Nutrition Facts label is a percentage calculated by dividing the amount of Vitamin C in one serving of the food by the DV. Using an example from the above chart, ½ cup of mashed papaya, which contains 70 mg of Vitamin C, would have 117% of the DV for Vitamin C. The FDA requires that the DV for Vitamin C be listed on the Nutrition Facts label.

In Canada: The daily value for Vitamin C in Canada is also 60 mg. Canadian labeling laws also require that the DV for Vitamin C be listed on the Nutrition Facts label.

Nutrient Interactions

Iron: Vitamin C (from food sources and/or supplements) increases the absorption of iron when taken at the same time.

Copper: Supplemental intake of Vitamin C at very large doses (1,500 mg daily) can interfere with copper metabolism.

Vitamin E: Vitamin C is involved in the regeneration of Vitamin E, and these two vitamins appear to work together in their antioxidant effect.

Carolyn Berry, RD

Alumni: University of British Columbia – Carolyn Berry is a Vancouver-based Registered Dietitian, self-proclaimed foodie, marathon runner, and owner of Berry Nourished. Carolyn works in a variety of areas including clinical nutrition, outpatient counselling at Medisys Preventive Health Clinic, as a nutrition tour leader with Save-On-Foods, and in the media, including segments on CBC Television, CKNW and Spice Radio. Through informative and practical nutrition advice and her food-first approach to health, Carolyn fulfills her passion to empower others with knowledge about nutrition so that they can make the best decisions to improve their health. She strongly believes that food should be both healthful and delicious.