Vitamin C, also known as ascorbic acid, is a water-soluble nutrient found in some foods. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals. Free radicals are compounds formed when our bodies convert the food we eat into energy. People are also exposed to free radicals in the environment from cigarette smoke, air pollution, and ultraviolet light from the sun.
Historically, vitamin C was used for preventing and treating scurvy. Scurvy is now relatively rare, but it was once common among sailors, pirates, and others who spent long periods of time on-board ships. When the voyages lasted longer than the supply of fruits and vegetables, the sailors began to suffer from vitamin C deficiency, which led to scurvy.
The body also needs vitamin C to make collagen, a protein required to help wounds heal. 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.
Some animals can make their own vitamin C, but people must get this vitamin from food and other sources.
Vitamin C is used for preventing and treating the common cold. Some people use it for other infections including gum disease, acne and other skin infections, bronchitis, human immunodeficiency virus (HIV) disease, stomach ulcers caused by bacteria called Helicobacter pylori, tuberculosis, dysentery (an infection of the lower intestine), and skin infections that produce boils (furunculosis). It is also used for infections of the bladder and prostate.
Vitamin C deficiency
Vitamin C deficiency is rare. People who get little or no vitamin C (below about 10 mg per day) for many weeks can get scurvy. Scurvy causes fatigue, inflammation of the gums, small red or purple spots on the skin, joint pain, poor wound healing, and corkscrew hairs. Additional signs of scurvy include depression as well as swollen, bleeding gums and loosening or loss of teeth. People with scurvy can also develop anemia. Scurvy is fatal if it is not treated.
Fruits and vegetables are the best sources of vitamin C. You can get recommended amounts of vitamin C by eating a variety of foods including the following:
- Citrus fruits (such as oranges and grapefruit) and their juices, as well as red and green pepper and kiwifruit, which have a lot of vitamin C.
- Other fruits and vegetables—such as broccoli, strawberries, cantaloupe, baked potatoes, and tomatoes—which also have vitamin C.
The vitamin C content of food may be reduced by prolonged storage and by cooking. Steaming or microwaving may lessen cooking losses. Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually eaten raw.
How much vitamin C do I need?
The amount of vitamin C you need each day depends on your age. Average daily recommended amounts for different ages are listed below in milligrams (mg).
|Life Stage||Recommended Amount|
|Birth to 6 months||40 mg|
|Infants 7–12 months||50 mg|
|Children 1–3 years||15 mg|
|Children 4–8 years||25 mg|
|Children 9–13 years||45 mg|
|Teens 14–18 years (boys)||75 mg|
|Teens 14–18 years (girls)||65 mg|
|Adults (men)||90 mg|
|Adults (women)||75 mg|
|Pregnant teens||80 mg|
|Pregnant women||85 mg|
|Breastfeeding teens||115 mg|
|Breastfeeding women||120 mg|
If you smoke, add 35 mg to the above values to calculate your total daily recommended amount.
Can vitamin C be harmful?
Taking too much vitamin C can cause 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 damage body tissues.
The upper limits for vitamin C are listed below:
|Life Stage||Upper Limit|
|Birth to 12 months||Not established|
|Children 1–3 years||400 mg|
|Children 4–8 years||650 mg|
|Children 9–13 years||1,200 mg|
|Teens 14–18 years||1,800 mg|