Vitamin C

                             Vitamin C
Definition
                 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.

It has been suggested that daily intakes of vitamin C in excess of 

500 milligrams may be of benefit. There is some evidence that amounts

 of this kind may reduce the symptoms of the common cold. This raises

 the question of non-nutritional or drug-like properties of the vitamin. 

The possible adverse effects must also be considered. These include:'

rebound scurvy', which may occur if you are coming off high-dosage vitamin

 C; increased excretion of oxalic acid in the urine which may lead to

 'stones' in the urinary tract; an increased absorption of iron in those 

susceptible to iron overload; increased absorption of toxic metals, such 

as mercury; and interactions with certain medications, for example warfarin,

 aspirin, antidepressants and the contraceptive pill. is also known as 

ascorbic acid.

Approximately 5 to 10 mg of vitamin C is required daily to prevent scurvy.

 The RDA is set higher to ensure an adequate body pool to prevent scurvy

 after four weeks of low vitamin C intake. The 2000 recommendations are 15

 to 45 mg for children, 65 to 90 mg for adolescents, 75 mg for adult females,

 90 mg for adult males, 80-85 mg for pregnant women and 115-120 mg for

 lactating women.

Vitamin C blocks carcinogenic processes through antioxidant activity.

 Epidemiological studies have shown a strong association of vitamin C 

supplementation with decreased risk of cancer of the oral cavity, esophagus,

 stomach, and pancreas. Less strong associations were found with lung, cervix,

 rectum, and breast cancer.

The daily intake for a gatherer hunter would depend on the season, 

the particular ecosystem the tribe was living in, and the size of 

the family unit that shared whatever resource was available. The daily 

intake would probably have been well in excess of the RDA at times of year 

when fruit and greens were relatively abundant, and at other times may well

 have been much less. Either way, it is unlikely we took in 500 mg per day 

every day. The 500 mg so called 'optimum' probably reflects the need for a 

city living human to protect against stressful living, and the now wide

 exposure to damaging environmental chemicals. Such a level can only 

realistically be obtained by taking supplemental vitamin C.

Vitamin C is an important anti-oxidant, helps protect against cancers,

 heart disease, stress, it is part of the cellular chemistry that provides

 energy, it is essential for sperm production, and for making the collagen

protein involved in the building and health of cartilage, joints, skin, and

 blood vessels. Vitamin C helps in maintaining a healthy immune system, it

 aids in neutralizing pollutants, is needed for antibody production, acts

 to increase the absorption of nutrients (including iron) in the gut, and

 thins the blood. Just to mention its most important functions.

s a powerful antioxidant, vitamin C helps lessen oxidative stress

 to the body and is thought to lower cancer risk. The current RDA 

for vitamin C is 60mg, below is a list of foods high in vitamin C.

 For those looking to consume extremely high levels of vitamin C 

supplements are also available.

Oranges

Oranges, citrus fruits, and their zest (the shavings of their peel)

 are all high in vitamin C. Oranges provide 59mg (99% RDA) per 100

 gram serving, 98mg (163% RDA) per cup, and 83mg (138% RDA) per orange.

 Clementines, or tangerines, provide 49mg (81% RDA) per 100 gram serving,

 or 36mg (60% RDA) per fruit.

Consuming vitamin C supplements does not provide the same protective

 benefits as drinking a glass of orange juice, shows research by Italian 

researchers in the Division of Human Nutrition at the University of Milan,

 Italy (Guarnieri S, Riso P, et al., British Journal of Nutrition).

Seven healthy test subjects were given each of three drinks, two weeks

 apart: blood-orange juice containing 150 milligrams of vitamin C,

 fortified water containing 150 milligrams of vitamin C, and a sugar

 and water solution containing no vitamin C. Blood samples were collected

 immediately before the drink was consumed, then every hour for 8 hours,

 and finally 24 hours after consumption of each drink.

Blood samples were exposed to hydrogen peroxide, and free radical 

damage to DNA was evaluated at 3 and 24 hours. Only when orange juice

 was consumed was any protective effect seen. After drinking orange juice,

 DNA damage was 18% less after 3 hours, and 16% less after 24 hours. No

 protection against DNA damage was seen after consumption of the vitamin 

C fortified drink or the sugar drink.

While another study, which looked at much larger quantities of vitamin C,

 did show a protective effect from the vitamin alone, this research indicates

 that not only is the protection afforded by fruit more complex, but smaller

 amounts of nutrients like vitamin C are all that are needed for benefit.

Said lead researcher, Serena Guarnieri, "It appears that vitamin C is 

not the only chemical responsible for antioxidant protection." In oranges,

 vitamin C is part of a matrix involving many beneficial phytochemicals 

(for example, cyanidin-3-glucoside, flavanones and carotenoids).. 

"But how they are interacting is still anyone's guess," she added.

 Fortunately, we don't have to wait until scientists figure this out

 to receive oranges' DNA-protective benefits. Practical Tip: For the 

best DNA protection, skip the vitamin C-fortified bottled drinks and 

enjoy a glass of real (preferably organic as organic foods have been 

shown to contain higher amounts of phytonutrients), freshly squeezed 

orange juiceâ€"or simply eat an orange!

Owing to the multitude of vitamin C's health benefits, it is not

 surprising that research has shown that consumption of vegetables 

and fruits high in this nutrient is associated with a reduced risk 

of death from all causes including heart disease, stroke and cancer.

Oranges' health benefits continue with their fiber; a single orange

 provides 12.5% of the daily value for fiber, which has been shown to

 reduce high cholesterol levels thus helping to prevent atherosclerosis.

 Fiber can also help out by keeping blood sugar levels under control, 

which may help explain why oranges can be a very healthy snack for 

people with diabetes. In addition, the natural fruit sugar in oranges,

 fructose, can help to keep blood sugar levels from rising too high 

after eating. The fiber in oranges can grab cancer-causing chemicals 

and keep them away from cells of the colon, providing yet another line

 of protection from colon cancer. And the fiber in oranges may be 

helpful for reducing the uncomfortable constipation or diarrhea in

 those suffering from irritable bowel syndrome.

The obvious choice when it comes to the best foods with vitamin C

 is oranges, which provide about 116% of your recommended daily 

intake of the vitamin. Eating the orange slices as is is the best

 source of the vitamin, but you can turn the oranges into juice 

or buy 100% orange juice as well. The more you cook the fruit–in

 other words, if you make marmalade or other orange desserts–the 

less vitamins are retained.