Role of Vitamin C

Most people associate vitamin C with boosting the immune system, but its role in health is much more significant. It is involved in protein metabolism and the biosynthesis of collagen, which makes up the connective tissue of joints. Vitamin C also enhances the absorption of non-heme iron (iron from plant-based foods).

Recommended Intake

The recommended dietary allowance (RDA) of vitamin C for adults over 19 is 90 milligrams per day for men and 75 milligrams per day for women. The intake recommendation rises to 85 milligrams per day for pregnant women and 120 milligrams for breastfeeding women. Smoking increases the need for vitamin C. Male smokers should increase their intake to 125 milligrams per day, and women smokers need 110 milligrams daily.

Vitamin C & the Common Cold

Vitamin C may help fight against diseases through its action as an antioxidant. However, when it comes to the common cold, the results of studies on vitamin C have been mixed. In the general population, regular high doses of vitamin C do not appear to decrease the risk of getting a cold. Some research shows it may reduce the duration of a cold and reduce the severity of symptoms. These results are linked to regular intake of the vitamin. Studies showed that taking vitamin C after the cold symptoms started did not influence the symptoms or duration of the illness.

Sources for Vitamin C

Citrus fruits are often the first sources of vitamin C that come to mind, but it can be found in a variety of fruits and vegetables. Sweet red peppers contain one of the highest levels, with 208.8 milligrams in one large pepper. One cup of strawberries provides 89.4 milligrams of vitamin C. A medium navel orange contains 82.7 milligrams. Other sources include kiwifruit, broccoli, Brussels sprouts, tomatoes, and cantaloupe. Some cereals, juices, and fruit drinks are also fortified with vitamin C.

Sources

• National Institutes of Health - Vitamin C
• Oregon State University Linus Pauling Institute - Vitamin C

Lori Rice, M.S., is a nutritional scientist and author with a passion for healthy cooking, exercise physiology, and food photography.