Facts About Vitamin C - Learn All About Vitamin C, Including Good Food Sources
Vitamin C Properties
- Other names: ascorbic acid, L-ascorbate
- Chemical formula: C6H8O6
- Fat or water soluble? Water soluble
- Forms: The ascorbate anion may be found in the form of an acid (ascorbic acid). Citric acid is not vitamin C, though it may be confused with vitamin C because many foods high in the vitamin also contain citric acid.
- Recommended daily intake: 90 mg for men and 75 mg for women, with an extra 35 mg recommended for smokers
Roles in the Body
Vitamin C aids with the absorption of iron. It is essential to the synthesis of collagen, a protein used in connective tissue; thus vitamin C helps with wound healing, the maintenance of bones and cartilage, and the health of skin and blood vessels. As an antioxidant, it helps neutralize free radicals (oxidizers) that can damage cells and lead to cancer. This activity is the reason smokers are advised to consume extra vitamin C, since tobacco smoking increases oxidative stress. Vitamin C is water soluble, so it cannot be stored in the body and must be consumed on a daily basis.
Vitamin C Deficiency (Scurvy)
Scurvy symptoms include anemia (because vitamin C is necessary for iron absorption), easy bruising and/or internal bleeding (because vitamin C helps maintain blood vessels), and sores and bleeding in the mouth (because vitamin C is needed for maintenance of healthy teeth and bones). Other symptoms may be present, such as sunken eyes, muscle and joint pain, weakness, and fatigue. Though rare in developed nations, it is occasionally seen in alcoholics, people undergoing chemotherapy, and those who consume very poor diets lacking in fruits, vegetables, and supplements.
High Doses of Vitamin C
Vitamin C is sometimes touted as a treatment for upper respiratory infections, i.e. the common cold. Despite numerous studies, there is no evidence that a high daily dose of vitamin C can prevent colds, though it may slightly reduce the duration of a cold. A vitamin C mega-dose is considered to be a dose over 1 gram (1000 mg), over ten times the recommended daily minimum. It is absorbed well up to about 1.5 grams per day.
Vitamin C overdoses are rare because the substance is excreted so readily. Consumption of very large amounts of the vitamin in supplement form may cause temporary diarrhea or other gastrointestinal symptoms, and in rare cases may be associated with kidney stones.
Food Sources of Vitamin C
Vitamin C is found mainly in fruits and vegetables, since it is not generally stored in the bodies of animals. The best sources include guavas, red bell peppers, citrus fruits and juices, broccoli, and strawberries. Lesser but still significant sources include mangoes, tomatoes, cantaloupe, potatoes (with the skin), kohlrabi, and green bell peppers. Cooking reduces the amount of vitamin C in food, so for the most benefit, vitamin C foods should be eaten either raw or cooked for the shortest amount of time possible. If possible, they should not be stored or cooked in water, since the vitamin is water-soluble.
References
- Scurvy. Langone Medical Center.
- Vitamin C (pdf). University of Washington Department of Family Medicine.
- Vitamin C (Ascorbic Acid). Ohio State University Extension Fact Sheet.
This post is part of the series: The Facts About Vitamins and Minerals Series
Get a healthy dose of facts without the hype on the vitamins and dietary minerals needed by the human body. Find out interesting facts, food sources, and more about the major vitamins and minerals.