Vitamin C is also known as ascorbic acid. Vitamin-C is a water-soluble nutrient that is found in some foods.
Functions of Vitamin C:
In the body vitamin C is act as an anti-oxidant that help in protecting cells from the damage caused due to free radicals. Free radicals are compounds that are formed in our bodies when food is converted into energy. Exposure to free radicals can also occur as a result of some environmental factors such as air pollution, UV light from the sun, cigarette smoke.
Vitamin-C is also required by the body to make a protein named as collagen which is required for the healing of wounds. Furthermore, vitamin-C is also involved in the iron absorption from plant based foods. Vitamin-C also helps in proper working of immune system which protect the body from different diseases.
Daily requirements of vitamin-C depends on age. On average recommended amounts of vitamin-C in milligrams on daily basis are listed below:(1232)
|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|
Best sources of vitamin-C are vegetables and fruits. Variety of foods can be consumed to get recommended amounts of Vitamin-C. These foods include:
- Citrus fruits such as grapefruit and oranges and their juices, green and red pepper and kiwi fruit which are rich in vitamin-C.
- Other vegetables and fruits such as strawberries, broccoli, tomatoes, bakes potatoes and cantaloupe which are also rich in vitamin-C.
- Vitamin-C fortified foods and beverages. Product labels can be checked to find out that vitamin C has been added to a food product or not.
Prolonged storage and cooking results in decreasing the content of Vitamin-C in the food. Microwaving or steaming may help in reducing the cooking losses. Fortunately, best sources of vitamin-C such as vegetables and fruits, are usually eaten raw.(545345)
|Food||Milligrams (mg) per serving||Percent (%) DV|
|Red pepper, sweet, raw, ½ cup||95||158|
|Orange juice, ¾ cup||93||155|
|Orange, 1 medium||70||117|
|Grapefruit juice, ¾ cup||70||117|
|Kiwifruit, 1 medium||64||107|
|Green pepper, sweet, raw, ½ cup||60||100|
|Broccoli, cooked, ½ cup||51||85|
|Strawberries, fresh, sliced, ½ cup||49||82|
|Brussels sprouts, cooked, ½ cup||48||80|
|Grapefruit, ½ medium||39||65|
|Broccoli, raw, ½ cup||39||65|
|Tomato juice, ¾ cup||33||55|
|Cantaloupe, ½ cup||29||48|
|Cabbage, cooked, ½ cup||28||47|
|Cauliflower, raw, ½ cup||26||43|
|Potato, baked, 1 medium||17||28|
|Tomato, raw, 1 medium||17||28|
|Spinach, cooked, ½ cup||9||15|
|Green peas, frozen, cooked, ½ cup||8||13|
Dietary supplements of Vitamin C:
Most multivitamins are composed of vitamin C. Dietary supplements of vitamin C are also available in which alone vitamin C is present. Vitamin C is also present in combination with other nutrients. In dietary supplements, vitamin C is usually present in the form of ascorbic acid but it is also present in other forms in some supplements, such as calcium ascorbate, sodium ascorbate, other mineral ascorbates and bioflavonoids with ascorbic acid. There is no evidence that shows that any vitamin C form is better than other form.
People suffering from Deficiency of Vitamin C:
In United States people get sufficient amount of vitamin-C from beverages and food. Although some groups of people feel trouble in getting enough amount of vitamin-C than others. Some of these are discussed below
· Smokers and those exposed to secondhand smoke need more amount of vitamin-C than the recommended amounts that body normally needs because there is a need to repair the damages caused by free radicals in the body due to smoking. Smokers require 35 mg more vitamin-C than the non-smokers.
· Infants who feed on boiled or evaporated cow’s milk suffer from vitamin-C deficiency because very little vitamin-C is present in cow’s milk and further if the milk is heated it results in destroying of vitamin-C present in milk. For infants under the age of one year cow’s milk is not recommended. Infant formula and breast milk have sufficient amount of vitamin-C.
· If limited variety of foods are eaten by people it will also result in vitamin-C deficiency.
· People suffering from certain medical conditions like kidney diseases requiring hemodialysis, severe malabsorption, some types of cancer.
In United States and Canada people will suffer from scurvy if they get little or no vitamin-C i.e., less than 10 mg per day for many weeks. Symptoms of scurvy include inflammation of the gums, fatigue, joint pain, small purple or red spots on the skin, corkscrew hairs, and poor wound healing. Additionally, scurvy is also responsible to cause some other symptoms including depression, swelling and bleeding of gums and loss of teeth. People suffering from scurvy can also develop anemia. If scurvy is not treated it will become fatal.
Health effects of Vitamin C:
Scientists are studying the health effects of vitamin-C for better understanding. Some of these are discusses below:
Cancer Prevention and Treatment:
If a person takes high amount of vitamin C from vegetables and fruits he/she will be at a lower risk of developing many kinds of cancer such as colon, breast and lung cancer. However, if supplements of vitamin-C are consumed with or without other antioxidants it does not seem to provide protection from getting cancer. It is not clear that Whether high doses of vitamin-C are helpful in treatment of cancer or not. Effects of vitamin-C on patient’s body depend upon the method of administration of vitamin-C in the body. Blood levels of vitamin-C cannot be raised by using oral doses of vitamin-C. However high blood levels of vitamin C can be achieved through intravenous doses given by injections. A few studies in test tubes and animals shows that elevated blood levels of vitamin-C might help in shrinking tumors. But further research is required to find out that whether high intravenous doses of vitamin-C help in treating cancer or not.
Dietary supplements of vitamin C and some other antioxidants might show interactions with radiotherapy and chemotherapy used for the treatment of cancer. People taking cancer treatment should take proper advice of oncologists before consuming any antioxidant supplements or vitamin-C, especially in high doses.
People who consumes lots of vegetables and fruits are at lower risk of developing cardiovascular disease. It is believed by the researcher that antioxidant content of these fruits and vegetables might be responsible for this effect because major cause of cardiovascular disease is oxidative damage. Although scientists are not confirmed about whether vitamin C itself or from food or supplements helps in protecting people from cardiovascular disease. Furthermore, it is also not clear that vitamin C help in preventing the worsening of cardiovascular disease in people who are already suffering from it.
Cataracts and Age-related macular degeneration (AMD):
In older people cataracts and AMD are too leading causes of vision loss. Researches don’t believe that antioxidants and vitamin C affect the risk of getting AMD. Although research suggests that if vitamin C is combined with some other nutrients it might help in slowing the progression of AMD.
One large study was conducted among older people suffering from AMD and are at a high risk of developing advanced AMD. In this study those who consume a dietary supplement of vitamin C 500 mg on daily basis, 400 IU vitamin E, 80mg zinc, 2 mg copper, and 15 mg beta-carotene for the period of about 6 years had a lower chance of developing advanced AMD. Less vision loss is seen in these people as compared to other people who did not consume dietary supplements. People who are suffering from the disease or developing the disease should talk to their doctor before consuming any dietary supplements.
The link between cataract formation and vitamin C is unclear. Certain studies show that people who consume high amount of vitamin C from foods are at lower risk of developing cataracts. But more research is required to clarify this relationship and to determine whether supplements of vitamin C affect the risk of developing cataracts.
The common cold:
Vitamin C has been used since long times as a popular remedy for the treatment of common cold but some researches showed that supplements of vitamin C don’t help in reducing the risk of getting the common cold. When people suffer from common colds if supplements of vitamin C are taken regularly it might help in reducing the symptoms of common cold. If vitamin C supplements are taken after the symptoms of cold had started then in this case it does not seems to be helpful.
Harmful effects of Vitamin C:
If vitamin C is taken in very high amounts it can result in stomach cramps, common nausea and diarrhea. People suffering from hemochromatosis a condition in which body stores too much amount of iron, elevated doses of vitamin C could worsen overloading of iron and cause damage to body tissues.
Daily requirements of Vitamin C:
List shows the upper limits of vitamin C:
|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|
Interactions of Vitamin C with other medications:
Dietary supplements of vitamin C can show interactions with other medicines. Some of the examples are discussed below:
- Dietary supplements of vitamin C might show interactions with cancer treatments such as radiotherapy and chemotherapy. Scientists are not clear that whether vitamin C might show the unwanted effect of protecting cancer cells from cancer treatments or whether it might help in protecting normal tissues from getting damage. If a person is undergoing cancer treatment he/she should take proper advice of health care provide before consuming any antioxidant supplement or vitamin C, especially in high doses.
- In another study when vitamin C is consumed in combination with any other antioxidants such as selenium, beta-carotene, and vitamin E, this combination reduced the protective effect of two drugs on the heart. These two drugs that are used in combination are niacin and statin. They are used to control the cholesterol levels in the blood. But it is not clear that whether this type of interaction also occurs with another statin or not. Lipid levels of people taking both antioxidant supplements and statin should be monitored properly by the health care providers.
Healthful Eating and Vitamin C:
According to the Dietary Guidelines of federal government for Americans most of the nutrients should be obtained from healthy foods. Foods are composed of dietary fibers, minerals, vitamins and some other substances that provide health benefits. In certain cases, dietary supplements and fortified foods may help in providing nutrients that may be otherwise consumed in less-than- recommended amounts.
This fact paper by Office of Dietary Supplements gives a piece of knowledge that should not replace the medical prescription. We foster you to communicate with your healthcare adviser (doctor, pharmacist, dentist etc.) for your interest in, queries about, or use of supplements and what could be best for your health.