Definition of Vitamin C
Vitamin C: An essential nutrient found mainly in fruits and
vegetables. The body requires vitamin C to form and maintain bones,
blood vessels, and skin.
Like other vitamins, vitamin C is an organic compound. An organic
compound is a substance that (1) occurs in living things, or
organisms (hence, the word "organic") and (2) contains the elements
carbon and oxygen (hence, the word "compound," meaning combination of
elements). Vitamin C is also known as ascorbic acid.
Type of Vitamin
Vitamin C is a water-soluble vitamin, one that cannot be stored by
the body except in insignificant amounts. It must be replenished
daily.
Purpose and Benefits
Vitamin C helps produce collagen, a protein needed to develop and
maintain healthy teeth, bones, gums, cartilage, vertebrae discs,
joint linings, skin and blood vessels. Vitamin C also does the
following:
1. Promotes the healing of cuts, abrasions and wounds.
2. Helps fight infections.
3. Inhibits conversion of irritants in smog, tobacco smoke, and
certain foods into cancer-causing substances.
4. Appears to dilate (widen, enlarge) blood vessels and thereby
lessen the risk of developing high blood pressure and heart disease.
5. Helps regulate cholesterol levels.
6. Prevents the development of scurvy, a disease characterized by
weakness, fatigue, anemia, swollen joints, bleeding gums and loose
teeth. Scurvy was common aboard ships in earlier times because crews
traveled for long
periods without eating fresh vegetables or fruit. Many sailors died
of the disease. Scurvy is rare today.
7. Appears to lower the risk of developing cataracts, clouding of
the lens of the eye that impairs vision.
8. May help protect diabetics against deterioration of nerves,
eyes and kidneys.
9. May inhibit the development of colds and decrease the
intensity of cold symptoms. (This is controversial.)
10. Aids iron absorption.
11. May reduce levels of lead in the blood.
Food Sources
Fruits: oranges, lemons, limes, grapefruits, tangerines, pears,
bananas, melons, papayas, strawberries, mangos, blackberries,
blueberries, kiwis, pineapples, watermelons, raspberries,
cranberries, cantaloupes, rose hips,
acerola cherries.
Vegetables: asparagus, broccoli, green peppers, red peppers,
cabbage, kale, cauliflower, potatoes, sweet potatoes, yams, squash,
peas, turnips, turnip greens, onions, corn, pumpkins, carrots,
parsley, sauerkraut.
Herbs: garlic, watercress.
Other sources: fish and milk (occurs in small amounts).
Preservation
Fruits and vegetables lose vitamin C quickly, especially when
exposed to heat. For this reason, fruits and vegetables should not be
cooked in water. Rather, they should be cooked over
water--for example, in
a double boiler. Pots should not contain copper. Copper can also
destroy vitamin C. Canned foods generally preserve vitamin C until
opened.
Recommended Daily Intake in Milligrams
Infants from birth to 1 year: 30 to 35 mg
Babies 1 to 3 years: 40 mg
Children 4 to 10: 45 mg
Pregnant women: 75-90 mg
Lactating women: 75-90 mg
Smokers: 100 mg
Diabetics, elderly persons, patients suffering from stress or
allergies: up to 200 mg, as determined by a physician.
All others: 60 mg (unless a physician indicates otherwise).
A milligram equals 1/1000 of a gram. A gram equals .0353 of an
ounce.
Side Effects From Overdose
Some patients taking large amounts of vitamin C may
experience diarrhea, nausea, skin irritation, burning upon urination, and depletion of the mineral copper. Also, there is some evidence
that large doses of vitamin C may contribute to the development of
kidney stones. In addition, persons with iron overload or a condition
called glucose-6-phosphate dehydrogenase (G6PD)
deficiency (an inherited condition affecting the red blood cells) may
need to monitor their intake of vitamin C according to a physician's
instructions.
Toxicity
Laboratory studies have shown that vitamin C can induce the formation of genotoxins (agents that damage DNA). If generated in significant amounts, these genotoxins could generate mutations and so conceivably contribute to cancer.
Interactions
Vitamin C can cause adverse reactions when taken with some drugs.
Therefore, patients taking drugs should always read warning labels
and advisories on containers and printed pharmacy instructions. If in
doubt about a possible
reaction, patients should consult a pharmacist or physician.
Supplements
Vitamin C is available as a supplement in the form of tablets,
powders and liquids.
Derivation
The "vita" in "vitamin" is derived from the Latin word "vita"
(life). A vitamin, thus, is a nutrient required to sustain life.
See also: Paprika.
Last Editorial Review: 6/17/2004
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