| In the late eighteenth century English sailors carried
limes on long voyages to ward off scurvy, which led to them being given
the nickname ‘limeys’. But it was not until 1932 that
ascorbic acid (vitamin C), a water-soluble white powder, was isolated and
identified as the substance in certain foods responsible for curing
scurvy.
What does it do for your body?
Vitamin C is involved in over 300 biological processes in the body.
Collagen - Vitamin C is necessary for the manufacture
of collagen, the protein which forms the basis of connective tissue. The
most abundant tissue in the body, connective tissue acts as a cementing
substance between cells. It helps support and protect blood vessels, bones,
joints, organs and muscles and forms a sizeable proportion of skin, tendons,
the cornea of the eye, ligaments, cartilage, teeth and bone. Collagen forms
a protective barrier and promotes healing of wounds, fractures and bruises.
Antioxidant - Vitamin C is the body’s most powerful
water-soluble antioxidant and plays a vital role in protecting the body
against oxidative damage. It neutralizes potentially harmful reactions in
the watery parts of the body such as the blood and the fluid inside and
surrounding cells. It helps protect LDL cholesterol against free radical
damage. This antioxidant action helps to protect the health of the heart and
an array of other body tissues.
Hormones - Vitamin C is important in the synthesis of
hormones by the adrenal glands.
Cardiovascular System - Vitamin C plays a role in
cholesterol production in the liver and in the conversion of cholesterol to
bile acids for excretion. It supports normal total blood cholesterol and LDL
cholesterol and raises beneficial HDL cholesterol. Vitamin C also supports
normal circulation, therefore supporting the health of the heart. Vitamin C
also helps control healthy blood pressure.
Nervous System - Vitamin C plays a role in the
conversion of tryptophan to serotonin, a neurotransmitter with many vital
functions.
Absorption: Body tissue stores of vitamin C are small
and easily saturated, with any excess excreted in two to three hours.
Deficiency: Vitamin C deficiency is extremely rare. A
lack of vitamin C leads eventually to scurvy. The symptoms are mainly due to
poorly formed collagen and include the breaking open of small blood vessels,
the reddening and bleeding of gums, loose teeth, joint pains, dry scaly skin
and blood vessel damage. Other symptoms include general weakness, fluid
retention, depression, and anemia.
Vitamin C deficiency can lead to slower wound healing, increased
susceptibility to infections, male infertility and increased genetic damage
to sperm cells which may lead to birth defects. It may also contribute to
rheumatoid arthritis and gastrointestinal disorders.
Therapeutic effects: Vitamin C has a number of health effects
Cardiovascular System - Vitamin C may protect the heart by preventing
the oxidation of artery clogging LDL cholesterol. Studies have shown that
high vitamin C intake is linked to heart health. Vitamin C may also be of
benefit in the support of normal high blood pressure and circulation.
Lungs - There is some evidence that vitamin C may be of benefit in
maintaining the health of the respiratory system. This effect may be due to
the antioxidant effect of vitamin C on oxidizing agents. Vitamin C may also
improve lung and white blood cell function and decrease respiratory stress.
Immunity - Vitamin C boosts immunity by increasing the production of B and T cells and
other white blood cells, including those with a critical role in natural defenses. It also
increases interferon levels and antibody responses and has antiviral and antibacterial
effects. These immune-stimulating effects lead to improved resistance against infections.
Though the research is contradictory and inconclusive, Vitamin C may reduce the duration of colds and the severity of cold symptoms such as
sneezing, coughing and sniffling by reducing blood levels of histamine, which can trigger
tissue inflammation and runny noses. It may also protect the immune cells and surrounding tissue from oxidative
reactions that occur when cells fight bacteria.
Cataracts - Many studies show that vitamin C may protect the health of the eye, possibly
by reducing ultra violet damage. Vitamin C is highly concentrated in the lenses of normal
eyes which may contain 60 times the amount of vitamin C as the blood, while stressed
lenses have levels that are much lower. Vitamin C may act to protect the lens from
oxidative damage and protect enzymes within the lens that remove oxidation damaged
proteins.
Diabetes - Increasing vitamin C intake in diabetics may support circulation, especially
micro-circulation.
Other Benefits - Vitamin C may also protect the skin from sun damage
and improve response to
stress, including an improvement in athletic performance due to the effects on adrenal
hormones.
Interactions: Vitamin C helps in the body’s absorption of iron by
helping convert dietary iron to a soluble form. It is also involved in the conversion of
folic acid to its active state. Vitamin C deficiency may lead to increased excretion of
vitamin B6, and vitamin B-6 deficiency leads to low levels of vitamin C, as can a deficiency
of vitamin A. Vitamin C protects against the toxic effects of cadmium, copper, vanadium,
cobalt, mercury and selenium. Large doses of vitamin C may lower vitamin
B-12, copper and
selenium blood levels. Calcium and manganese supplements may decrease vitamin C excretion
and vitamin C supplements may increase manganese absorption.
Exposure to cigarette smoke or air pollutants such as ozone and carbon monoxide may
deplete vitamin C in the lungs.
Large doses of vitamin C may interfere with contraceptive pill absorption and reduce its
effectiveness.
Aspirin, alcohol antibiotics and steroids may increase vitamin C requirements.
Vitamin C may diminish the response to some antidepressants, and the anticoagulant drug
warfarin. |
