Vitamin C

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Vitamin C is a water-soluble, antioxidant vitamin. An important nutrient necessary or human life, vitamin C is necessary for normal growth and development. It plays a key role in the formation of collagen, a protein that gives structure to bones, cartilage, muscle, and blood vessels. Vitamin C helps the absorption of iron by the body and maintains capillaries, bones, and teeth.

It was in the seventeenth century that a ships surgeon recommended the use of lemon juice as a preventive and cure. However, it was not until 1928 that Vitamin C was isolated from various food sources. Later discoveries confirmed its usefulness and it was widely recommended as a dietary supplement. Soon it was more familiar to the general public than any other nutrient. Studies indicated that more than 40% of older individuals in the U.S. took vitamin C supplements.[1]

Why should I be aware of this?

  • The body does not manufacture vitamin C on its own, nor does it store it. It is therefore important to include plenty of vitamin C-containing foods in our daily diet
  • Water-soluble vitamins dissolve in water. The body cannot store them. Leftover amounts of the vitamin leave the body through the urine. That means we need a continuous supply of such vitamins in your diet
  • Vitamin C is required for the growth and repair of tissues
  • Vitamin C is one of many antioxidants.
  • Humans vary greatly in their vitamin C requirement.
  • We should be able to get all the vitamin C you need from your daily diet.
  • In general, an unripe food is much lower in vitamin C than a ripe one.
  • In ripe food items, the vitamin C content is higher when the food is younger at the time of harvest.

All about vitamin C

Vitamin C is required for the synthesis of collagen, an important structural component of blood vessels, tendons, ligaments, and bone. It also plays an important role in the synthesis of the neurotransmitter, norepinephrine. Unlike most mammals, humans do not have the ability to make their own vitamin C.

Vitamin C requirement

The requirememnt of vitamin C varies from person to person. It is natural for one person to need 10 times as much vitamin C as another person. Moreover, a person's age and health also determine his requirement for vitamin C. An average adult needs 40 mg of vitamin C a day.

While the recommended daily or dietary allowance (RDA) stands now at 75 - 90 mg per day for adults, a higher dietary reference intake (DRI) is again in review. Regardless, many of those who regularly supplement Vitamin C, take in the vicinity of 250 -1,000+mg per day, and there are those who take up to, and beyond 10,000 mg daily.

Food sources

The amount of vitamin C found in food varies as dramatically as our human requirement. All fruits and vegetables contain some amount of vitamin C. Foods that tend to be the highest sources of vitamin C include green peppers, citrus fruits and juices, strawberries, tomatoes, broccoli, [turnip green]]s and other leafy greens, sweet and white potatoes, and cantaloupe.

Other excellent sources include papaya, mango, watermelon, brussels sprouts, cauliflower, cabbage, winter squash, red peppers, raspberries, blueberries, cranberries, and pineapples.

Too much vitamin C

Vitamin C toxicity is very rare, since it cannot be stored by the body. The body flushes the excess vitamin C through urine. However, amounts greater than 2,000 mg/day are not recommended because such high doses can lead to stomach upset and diarrhea.

Too little vitamin C

Too little vitamin C can lead to signs and symptoms of deficiency, including:

  • Dry and splitting hair
  • Decreased ability to fight infection
  • Bleeding gums
  • Rough, dry, scaly skin
  • Decreased wound-healing rate
  • Easy bruising
  • Swollen and painful joints
  • Gingivitis (inflammation of the gums)
  • Weakened tooth enamel
  • Possible weight gain because of slowed metabolism
  • Anemia
  • Nosebleeds

A severe form of vitamin C deficiency is known as scurvy, which mainly affects older, malnourished adults.

Useful tips

Vitamin C can be lost from foods during preparation, cooking, or storage. To prevent loss of vitamin C:

  • try serving fruits and vegetables raw.
  • If you need to cook it, go for steaming, simmering or boiling foods with very little water, or microwave them for a very short duration.
  • Try having fresh juice. If you need to store it, do not refrigerate it for more than two to three days.
  • Cook potatoes in their skins.
  • Store cut, raw fruits and vegetables in airtight containers before refrigeration.
  • Do not soak or store in water as vitamin C will dissolve in the water.

Vitamin C and health

Apart from its role in collagen formation, vitamin C also protects the fat-soluble vitamin A and vitamin E as well as fatty acids from oxidation. Vitamin C

  • Is useful in the treatment of anemia. Vitamin C
  • Prevents and cures the disease scurvy,
  • Help protect cells from free radical damage
  • Regenerate vitamin E supplies
  • Lower your cancer risk
  • Improve iron absorption

Cause of concern

Do meet a doctor if there is

  • Frequent colds or infections
  • Poor wound healing
  • Lung-related problems

Health conditions that need vitamin C

Most forms of cardiovascular disease, joint disease, cancer, eye disease, thyroid disease, liver disease, and lung disease require special emphasis on vitamin C intake. The process of aging itself requires special attention to vitamin C. In addition to these broader categories, several specific health conditions also require special emphasis on vitamin C. These specific health conditions include:

  • Autism
  • Acne
  • Depression
  • Alzheimer's disease
  • Asthma
  • Irritable bowel disease
  • Diabetes
  • Alcoholism
  • Parkinson's disease

90 degrees -- what we do not know yet

  • With higher vitamin C intake appear less likely to develop gout, a painful type of arthritis[2]
  • High-dose injections of vitamin C, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian and pancreatic cancers.[3]
  • The use of vitamin C in the prevention/treatment of the common cold and respiratory infections remains controversial, with ongoing research.


What can I do?

  • The best way to get the daily requirement of essential vitamins, including vitamin C, is to eat a balanced diet that contains a variety of foods from the food guide pyramid.
  • Vitamin C should be consumed every day because it is not fat-soluble and, therefore, cannot be stored for later use.


References

  • Vitamin C Medical Encyclopedia
  • Vitamin C
  • Vitamin C
  • Vitamin C Food Standard Agency
  • Vitamin C Mayo Clinic
  • Vitamin C supplementation
  • Vitamin C (Ascorbic Acid)

Source

  1. Vitamin C: Micronutrient Information Centre; Linus Pauling Institute
  2. Vitamin C Intake Associated With Lower Risk Of Gout In Men
  3. Vitamin C Injections Slow Tumor Growth In Mice