|
Vitamin C (Ascorbic Acid) is a very
important essential nutrient—that is, we must obtain it
from diet. It is found only in the fruit and vegetable
foods and is highest in fresh, uncooked foods. Vitamin C
is one of the least stable vitamins, and cooking can
destroy much of this water-soluble vitamin from foods.
In recent years, the C of this much-publicized vitamin
has also stood for controversy. With Linus Pauling and
others claiming that vitamin C has the potential to
prevent and treat the common cold, flus, and cancer, all
of which plague our society, concern has arisen in the
medical establishment about these claims and the megadose
requirements needed to achieve the hoped-for results. Some
studies suggest that these claims have some validity;
however, there is more personal testimony from avid users
of ascorbic acid than there is irrefutable evidence. There
has also been some recent research that disproves the
claims about treatment and prevention of colds and cancer
with vitamin C. However, in most cases, studies showing
vitamin C to be ineffective used lower dosages than Dr.
Pauling recommended. Overall, vitamin C research is
heavily weighted to the positive side for its use in the
treatment of many conditions, including the common cold.
C also stands for citrus, where this vitamin is found.
It could also stand for collagen, the protein "cement"
that is formed with ascorbic acid as a required cofactor.
Many foods contain vitamin C, and many important functions
are mediated by it as well.
Vitamin C is a weak acid and is stable in weak acids.
Alkalis, such as baking soda, however, destroy ascorbic
acid. It is also easily oxidized in air and sensitive to
heat and light. Since it is contained in the watery part
of fruits and vegetables, it is easily lost during cooking
in water. Loss is minimized when vegetables such as
broccoli or Brussels sprouts are cooked over water in a
double boiler instead of directly in water. The mineral
copper, in the water or in the cookware, diminishes
vitamin C content of foods.
Ascorbic acid was not isolated from lemons until 1932,
though the scourge of scurvy, the vitamin C deficiency
disease, has been present for thousands of years. It was
first written about circa 1500 B.C. and then described by
Aristotle in 450 B.C. as a syndrome characterized by lack
of energy, gum inflammation, tooth decay, and bleeding
problems. In the 1700s, high percentages of sailors with
the British navy and other fleets died from scurvy, until
James Lind discovered that the juice of lemons could cure
and also prevent this devastating and deadly disease. The
ships then carried British West Indies limes for the
sailors to consume daily to maintain health, and thus
these sailors became known as "limeys." Other cultures of
the world discovered their own sources of vitamin C.
Powdered rose hips, acerola cherries, or spruce needles
were consumed regularly, usually as teas, to prevent the
scurvy disease.
In earlier times, humans consumed large amounts of
vitamin C in their fresh and wholesome native diet, as
apes (another species that does not make vitamin C) still
do. Most other animals, except guinea pigs, produce
ascorbic acid in the liver from glucose, and in relative
amounts much higher than we get from our diets today. For
this reason, Dr. Pauling and others feel that our bodies
need somewhere between 2,000 and 9,000 mg. of vitamin C
daily. These amounts seem a little high to me, given the
basic food values of vitamin C. Some authorities feel we
need 600–1,200 mg. daily based on extrapolations from the
historical herbivore, early-human diet. These levels can
be obtained today by eating sufficient fresh food; a diet
that includes foods with high levels of vitamin C can
provide several grams or more per day.
Ascorbic acid is readily absorbed from the intestines,
ideally about 80–90 percent of that ingested. It is used
by the body in about two hours and then usually out of the
blood within three to four hours. For this reason, it is
suggested that vitamin C supplements be taken at four-hour
intervals rather than once a day; or it may be taken as
time-released ascorbic acid. Vitamin C is used up even
more rapidly under stressful conditions, with alcohol use,
and with smoking. Vitamin C blood levels of smokers are
much lower than those of nonsmokers given the same
intakes. Other situations and substances that reduce
absorption or increase utilization include fever, viral
illness, antibiotics, cortisone, aspirin and other pain
medicines, environmental toxins such as DDT, petroleum
products, or carbon monoxide, and exposure to heavy metals
such as lead, mercury, or cadmium. Sulfa antibiotics
increase elimination of vitamin C from the body by two to
three times.
Some ascorbic acid is stored in the body, where it
seems to concentrate in the organs of higher metabolic
activity. These include the adrenal glands (about 30 mg.),
pituitary, brain, eyes, ovaries, and testes. A total of
about 30 mg. per pound of body weight. We likely need at
least 200 mg. a day in our diet to maintain body
stores—much more if we smoke, drink alcohol, are under
stress, have allergies, are elderly, or have diabetes.
Vitamin C is a very complex and important vitamin. The
recommended amounts vary more widely than those for any
other nutrient, ranging from 100–80 or 100 grams daily,
depending on the condition. C is also the most commonly
supplemented vitamin among the general public, because of
either the popular press or its good effect, or because of
the other common C—the "cold."
Sources: The
best-known sources of vitamin C are the citrus
fruits—oranges, lemons, limes, tangerines, and
grapefruits. The fruits with the highest natural
concentrations are citrus fruits, rose hips, and acerola
cherries, followed by papayas, cantaloupes, and
strawberries. Good vegetable sources include red and green
peppers (the best), broccoli, Brussels sprouts, tomatoes,
asparagus, parsley, dark leafy greens, cabbage, and
sauerkraut. There is not much available in the whole
grains, seeds, and beans; however, when these are
sprouted, their vitamin C content shoots up. Sprouts,
then, are good foods for winter and early spring, when
other fresh fruits and vegetables are not as available.
Animal foods contain almost no vitamin C; though fish, if
eaten raw, has enough to prevent deficiency symptoms.
Natural vitamin C supplements are usually made from
rose hips, acerola cherries, peppers, or citrus fruits.
Vitamin C can be synthesized from corn syrup, which is
high in dextrose, much as it is made from glucose in most
other animals' bodies. Synthetic ascorbic acid, though it
can be concentrated for higher doses than natural
extracts, is still usually made from food sources. Sago
palm is another fairly new source of vitamin C
supplements. It is used primarily as a lower allergenic
source than the corn-extracted ascorbic acid.
Functions: One
important function of vitamin C is in the formation and
maintenance of collagen, the basis of connective tissue,
which is found in skin, ligaments, cartilage, vertebral
discs, joint linings, capillary walls, and the bones and
teeth. Collagen, and thus vitamin C, is needed to give
support and shape to the body, to help wounds heal, and to
maintain healthy blood vessels. Specifically, ascorbic
acid works as a coenzyme to convert proline and lysine to
hydroxyproline and hydroxylysine, both important to the
collagen structure.
Vitamin C also aids the metabolism of tyrosine, folic
acid, and tryptophan. Tryptophan is converted in the
presence of ascorbic acid to 5-hydroxytryptophan, which
forms serotonin, an important brain chemical. Vitamin C
also helps folic acid convert to its active form,
tetrahydrofolic acid, and tyrosine needs ascorbic acid to
form the neurotransmitter substances dopamine and
epinephrine. Vitamin C stimulates adrenal function and the
release of norepinephrine and epinephrine (adrenaline),
our stress hormones; however, prolonged stress depletes
vitamin C in the adrenals and decreases the blood levels.
Ascorbic acid also helps thyroid hormone production, and
it aids in cholesterol metabolism, increasing its
elimination and thereby assisting in lowering blood
cholesterol.
Vitamin C is an antioxidant vitamin. By this function,
it helps prevent oxidation of water-soluble molecules that
could otherwise create free radicals, which may generate
cellular injury and disease. Vitamin C also indirectly
protects the fat-soluble vitamins A and E as well as some
of the B vitamins, such as riboflavin, thiamine, folic
acid, and pantothenic acid, from oxidation. Ascorbic acid
acts as a detoxifier and may reduce the side effects of
drugs such as cortisone, aspirin, and insulin; it may also
reduce the toxicity of the heavy metals lead, mercury, and
arsenic.
Vitamin C is being shown through continued research to
stimulate the immune system; through this function, along
with its antioxidant function, it may help in the
prevention and treatment of infections and other diseases.
Ascorbic acid may activate neutrophils, the most prevalent
white blood cells that work on the frontline defense in
more hand-to-hand combat than other white blood cells. It
also seems to increase production of lymphocytes, the
white cells important in antibody production and in
coordinating the cellular immune functions. In this way
also, C may be helpful against bacterial, viral, and
fungal diseases. In higher amounts, ascorbic acid may
actually increase interferon production and thus activate
the immune response to viruses; it may also decrease the
production of histamine, thereby reducing immediate
allergy potential. Further research must be done for more
definitive knowledge about vitamin C's actions in the
prevention and treatment of disease.
Uses: There are
a great many clinical and nutritional uses for ascorbic
acid in its variety of available supplements. C for the
common cold is indeed used very widely; its use in the
treatment of cancer is more controversial, probably
because of the seriousness of the disease and the
political environment within the medical system—anything
nutritional or alternative in regard to cancer therapy is
looked upon with skepticism by orthodox physicians. For
the prevention of cancer, there is reason for more
optimism about the usefulness of vitamin C (as well as the
other antioxidant nutrients—vitamin E, selenium,
beta-carotene, and zinc) because of its effect in
preventing the formation of free radicals (caused mainly
by the oxidation of fats), which play a role in the
genesis of disease.
Given the functions of vitamin C alone, it has a wide
range of clinical uses. For the prevention and treatment
of the common cold and flu syndrome, vitamin C produces a
positive immunological response to help fight bacteria and
viruses. Its support of the adrenal function and role in
the production of adrenal hormones epinephrine and
norepinephrine can help the body handle infections and
stress of all kinds. Because of this adrenal-augmenting
response, as well as thyroid support provided by
stimulating production of thyroxine (T4) hormone, vitamin
C may help with problems of fatigue and slow metabolism.
It also helps counteract the side effects of cortisone
drug therapy and may counteract the decreased cellular
immunity experienced during the course of treatment with
these commonly used immune-suppressive drugs.
Because of ascorbic acid's role in immunity, its
antioxidant effect, the adrenal support it provides, and
probably its ability to make tissues healthy through its
formation and maintenance of collagen, vitamin C is used
to treat a wide range of viral, bacterial, and fungal
infections and inflammatory problems of all kinds. I have
used vitamin C successfully in many viral conditions,
including colds, flus, hepatitis, Herpes simplex
infections, mononucleosis, measles, and shingles.
Recently, vitamin C has been shown in some studies to
enhance the production and activity of interferon, an
antiviral substance produced by our bodies. To affect
these conditions, the vitamin C dosage is usually fairly
high, at least 5–10 grams per day, but it is possible that
much smaller doses are as effective. Vitamin C is also
used to treat problems due to general inflammation from
microorganisms, irritants, and/or decreased resistance;
these problems may include cystitis, bronchitis,
prostatitis, bursitis, arthritis (both osteo- and
rheumatoid), and some chronic skin problems (dermatitis).
With arthritis, there is some suggestion that increased
ascorbic acid may improve the integrity of membranes in
joints. In gouty arthritis, vitamin C improves the
elimination of uric acid (the irritant) through the
kidneys. Ascorbic acid has also been helpful for relief of
back pain and pain from inflamed vertebral discs, as well
as the inflammatory pain that is sometimes associated with
rigorous exercise. In asthma, vitamin C may relieve the
bronchospasm caused by noxious stimuli or when this
tight-chest feeling is experienced during exercise.
Vitamin C's vital function in helping produce and
maintain healthy collagen allows it to support the body
cells and tissues and bring more rapid healing to injured
or aging tissues. Therefore, it is used by many physicians
for problems of rapid aging, burns, fracture healing,
bedsores and other skin ulcers and to speed wound healing
after in-jury or surgery. Peptic ulcers also appear to
heal more rapidly with vitamin C therapy. The pre- and
postsurgical use of vitamin C supplementation can have
great benefits. With its collagen function, adrenal
support, and immune response support, it helps the body
defend against infection, supports tissue health and
healing, and improves the ability to handle the stress of
surgery. Vitamin A and zinc are the other important pre-
and postsurgical nutrients shown by research to reduce
hospitalization time and increase healing rates, thereby
preventing a number of potential complications.
Vitamin C is also used to aid those withdrawing from
drug addictions, addictions to such substances as
narcotics and alcohol, as well as nicotine, caffeine, and
even sugar—three very common addictions and abuses.
High-level ascorbic acid may decrease withdrawal symptoms
from these substances and increase the appetite and
feeling of well-being. For this reason, it may be helpful
in some depression and other mental problems associated
with detoxification during withdrawal. Vitamin C also may
reduce the effects of pollution, likely through its
antioxidant effect, its detoxifying help, and its adrenal
and immune support; specifically, it may participate in
protecting us from smog, carbon monoxide, lead, mercury,
and cadmium.
Vitamin C is a natural laxative and may help with
constipation problems. In fact, the main side effect of
too much vitamin C intake is diarrhea. For iron-deficiency
anemia, vitamin C helps the absorption of iron (especially
the nonheme or vegetable -source iron) from the
gastrointestinal tract. In diabetes, it is commonly used
to improve the utilization of blood sugar and thereby
reduce it, but there is no clear evidence that regular
vitamin C usage alone can prevent diabetes. There are some
preliminary reports that ascorbic acid may help prevent
cataract formation (probably through its antioxidant
effect) and may be helpful in the prevention and treatment
of glaucoma, as well as certain cases of male infertility
caused from the clumping together of sperm, which
decreases sperm function.
Vitamin C has a probable role in the prevention and
treatment of atherosclerosis and, thereby, in reducing the
risks of heart disease and its devastating results. It has
been shown to reduce platelet aggregation, a factor
important in reducing the formation of plaque and clots.
Ascorbic acid has a triglyceride- and cholesterol-reducing
effect and, more important, may help to raise the "good"
HDL. This action needs further investigation, though the
research is supportive so far. I haven't even mentioned
the prevention of scurvy, which really takes very little
vitamin C, about 10 mg. per day. This disease used to be a
big concern and was often fatal unless the victim ate some
citrus or other fresh fruit and vegetables containing a
small amount of vitamin C.
I do not really want to approach the cancer and vitamin
C issue; it deserves a book by itself. However, if we
closely analyze the functions (antioxidant, immune
support, interferon, tissue health and healing) that
vitamin C performs in the body, along with the still
mysterious influences of higher-dose ascorbic acid intake,
we can see how vitamin C may have a positive influence in
fighting and preventing cancer, our greatest
twentieth-century medical dilemma.
|