Vitamin C - to prevent infection, cancer and ageing!

Online Physician By Online Physician, 24th Sep 2011 | Follow this author | RSS Feed
Posted in Wikinut>Health>Diet & Nutrition

Vitamin C also known as ascorbic acid is found in almost all the fresh fruits and vegetables which have a sour taste. Being an antioxidant Vitamin C is known to reduce the risk of cancer and infection and is known to delay the process of ageing. This article gives a description on what is vitamin C, how was it discovered, the benefits of vitamin C, toxic effects, the sources and what happens when vitamin C becomes deficient in diet.

About Vitamin C...........

Vitamin C also known as ascorbic acid is an essential component in the diet. It is soluble in water and is destroyed easily by the heat. Vitamin C is found in large quantities in almost all the fresh fruits and vegetables which have a sour taste. Being an antioxidant Vitamin C is known to reduce the risk of cancer and infection and is known to delay the process of ageing. This article gives a description on what is vitamin C, how was it discovered, the benefits of vitamin C, toxic effects, the sources and what happens when vitamin C becomes deficient in diet.

How was Vitamin C discovered?

Vitamin C or ascorbic acid was first discovered when scientists were trying to find a cure for scurvy; which developed among sailors who were out in sea for long periods. In 1747 James Lind had found that the condition could be prevented by including fresh fruit juice in their diet. However vitamin C was found in 1928 by Albert Szent-Gyorgyi and he was awarded the Nobel Prize for Physiology and Medicine in 1937.

Intake of Vitamin C

Most animals and plants are capable of synthesizing ascorbic acid from glucose; except man, ape, guinea pig, insects, invertebrates and fish. Therefore humans have to take it from outside and the current recommendation 45mg per day.

On ingestion, ascorbic acid enters the body pool and is excreted in urine as ascorbic acid as well as several metabolites. It is distributed in all tissue, high concentrations found in pituitary, adrenal, brain, eye lens, liver, spleen, and kidney. Total body pool of ascorbic acid is 1500mg and the rate of degradation per day is 3% from the pool.

What are the functions of Vitamin C?

Vitamin C or Ascorbic acid is readily oxidized to dehydroascorbic acid and further to diketogulonic acid which is biologically inactive. It is the most active reducing agent in living tissue and it can act as an oxidant as well as an anti-oxidant.

Vitamin C is a co-factor to a number of enzymes that can be grouped as hydroxylases, these enzymes require molecular oxygen, Fe2+, a keto-acid and a reducing agent as co-factors. Reducing agent most active here is ascorbic acid.

Vitamin C is well-known as an antioxidant. It scavenges number of reactive oxygen species. This gives vitamin C the ability to act as an anti-ageing and anti-cancer agent. Iron vitamin C combinations are used to enhance absorption of iron.

It is said that vitamin C has the power to counteract infection for example it had been suggested that high doses like 1-2g per day will prevent common cold and people suffering from infectious ailments have been reported to be less saturated with ascorbic acid than healthy individuals on the same diet. Patients with scurvy are prone to infections especially of respiratory tract. However, there is no reasonable evidence to say that large doses of the vitamin protect against infections.

There have been reports of massive doses of the vitamin curing the cancer and prevent atherosclerosis. However there is no reliable evidence that doses up to 10g per day have any beneficial effect on survival of cancer.

In collagen (is a material which forms connective tissue in the body) synthesis, proline and lysine(amino acids) in protocollagen must be hydroxylated for the molecule to be able to form cross-links with other protocollagen molecules and change to collagen. If hydroxylation is inadequate, the connective tissue and basement membrane become weak and abnormally permeable. These changes particularly occur on gums and dental cement causing gum bleeding seen in scurvy; increased fragility of blood vessels causing spontaneous hemorrhage, abnormal formation of connective tissue in wound healing and abnormalities of bone and joints.

What happens in deficency - Scurvy!

Scurvy is the disease condition which is related with vitamin C deficiency in adults the early symptoms of deficiency may be non-specific; with weakness and muscle pain. Infants get scurvy when they were fed with pasteurized milk or milk powders as substitutes for breast milk and in infantile scurvy there is irritability, painful legs, anaemia (low blood hemoglobin) and characteristic subperiosteal haemorrhages, particularly into the ends of long bones. Other features of scurvy are as follows;
· Keratosis of hair follicles with ‘corkscrew’ hair
· Perifollicular haemorrhages
· Swollen, spongy gums with bleeding and superadded infection, loosening of teeth
· Spontaneous bruising
· Spontaneous haemorrhage
· Anaemia
· Failure of wound healing

What are the Sources of Vitamin C?

Ascorbic acid is found in all living tissues, abundance in fresh fruits and vegetables. In fruits, the outer portion contains more than the center. During cooking of vegetables, a portion of the vitamin passes into the water and is lost if the gravy is not consumed. Plant cells contain in their lysozymes (organelle in the cell), an enzyme ascorbic acid oxidase, which does not come into contact with the vitamin as long as the cell is intact but if liberated it oxidizes the vitamin.

Content of Vitamin C in Different Items of Food

When leaves and fruits are damaged by drying, bruising, pounding or cutting, or steeped into water, the enzyme is liberated and oxidizes the vitamin. Therefore, fruit and salad should be cut immediately before they are to be consumed before the enzyme destroys the vitamin. The enzyme can be destroyed before it has time to oxidize the vitamin, by plunging the material to be cooked directly into boiling water or heated oil. Placing vegetable in cold water which is brought slowly to its boiling point will help oxidation, as plant enzymes are very active at a 500C.

Heat facilitates oxidation of the vitamin even in the absence of the enzyme, specially oxygenated alkaline medium. Therefore, cooking in iron or copper vessels increases the rate of destruction. Also UV light inactivates the vitamin.

What happens in Excess?

Toxic effects reported with high intake of vitamin C as supplements include; acidosis, oxaluria, renal stones, glycosuria, renal tubular disease, gastrointestinal disturbance, vitamin B12 destruction, fatigue and sterility. In those who prone to form renal stones, they may form easily when large doses of ascorbic acid are given since it makes urine acidic. It is particularly seen in oxalosis (high oxalate levels in blood), hyperuricaemia (high uric acid levels) and cystinuria (secretion of cystine in urine); but there are evidence saying stones form in normal individuals without enzyme defects.

Vitamin C is an essential component in the diet. Adequate intake of vitamin C can be beneficial in the prevention of infections, cancer and athrosclerosis (precursor of ischaemic heart disease and stroke) and in delaying the process of ageing. Not only one apple a day but also one orange or a lemon a day can also keep your doctor away!

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Comments

author avatar Agnat
25th Sep 2011 (#)

Can Vit C help in reducing weight?

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author avatar avery sandiego
7th Nov 2011 (#)

Nice read on all about Vitamin C. It is effective, I was about to have a cold and I try to drink a Vit. c tablet and in the morning the cold is gone.

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author avatar Denise O
7th Feb 2012 (#)

Great information about vitamin C. Thank you for sharing.:)

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