Description
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Vitamin C
Vitamin C has many functions. It maintains collagen, wound healing, formation of red blood cells (RBCs), aids
in absorption of iron, fights bacterial infections, enhances white blood cell (WBC) production, and promotes
thymic hormone secretion. In addition to all of that, it is an antioxidant, aids in the metabolism of tyrosine, folic
acid and tryptophan, stimulates adrenal function, aids in thyroid hormone production and cholesterol
metabolism, acts as a detoxifier of certain metals and drugs, recycles other hydrogen donors such as vitamin E,
and aids in phagocytosis (digestion of damaged, dead or foreign cells).
Vitamin C is necessary for the enzyme reactions of many physiological processes, including collagen synthesis.
Unless vitamin C is present, a bridge forms in the collagen-builing enzyme and inactivates it. If vitamin C is
deficient, the collagen that is synthesized can't form fibers properly, resulting in skin lesions, blood vessel
fragility, and poor wound healing - in other words, the symptoms of scurvy.
Ascorbic acid was discovered in the 1700s when many British sailors died from scurvy. James Lind discovered
that the juice of lemons and limes could prevent scurvy, and from that point on, the sailors were known as
"limeys" because the ships were required to carry British West Indies limes to prevent scurvy. That is where
ascorbic acid got its name, from its anti-scorbutic properties.
Bioflavonoids
Bioflavonoids are found in green plants; they are closely associated with vitamin C, and they boost the
therapeutic effect of vitamin C, helping to build strong connective tissue, and create a protective barrier to
infection. Flavonoids have a positive, protective effect on human viruses (J. Med. Virol. 15:71-79). They seem to
reduce inflammation, and to protect cells (Biochem. Pharmacol. 45:13-9). When bioflavonoids were tested for
their ability to increase bacteria-engulfing white blood cells, the proliferation not only increased, but the
stimulating activity correlated with the concentration of flavonoids. (Biull. Eksp. Biol. Med. 114:520-21).
Clinical Applications/Research
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Clinical applications include the following: common cold, respiratory infections, flu, antioxidant function,
immune enhancement, adrenal and thyroid support, viral infections, inflammation, asthma, post-surgical
support, substance addiction, heavy metal toxicities, diabetes, eye problems (antioxidant effect), and heart
Heart Disease
The presence of hypercholesterolemia, hypertension, and atherosclerosis is more frequent in humans with a
low intake of vitamin C. Optimum intake of ascorbic acid to prevent these disorders ... “probably exceeds tenfold
the doses officially recommended and is in the range of some hundred milligrams of ascorbic acid per day"
(Miquel & Quintanilha The CRC Handbook of Free Radicals and Antioxidants in Biomedicine 1989; CRC Press,
Boca Raton, Fla. p. 194). The same handbook points out that prevalence of low vitamin C levels increases with
age, and, "the age-related rise in serum cholesterol may result from vitamin C deficiency" (ibid, p 192). Chronic
subclinical
deficiency, "...may result in progressive oxidative damage which in the long run
may lead to permanent
degenerative diseases in the heart" (Mol Cell Biochem 1992
111:41-7). For instance, it is known
that, "...regions with medium to high coronary mortality had a significantly lower vitamin C status" (Gey K et al.
Am J Clin Nutr
1987;45:p.1369).
In one
study, administration of gram doses of vitamin C led to a massive decrease
in
circulating triglycerides
(Sokoloff, B,
Hori, M, Saelhof, CC et al. J Am Geriatr Soc. 14:1239-60, 1966; Ginter, E, N
Engl J Med. 294:559-60, 1976.; Gooly, KL, Diamond, LH. Ann Intern Med. 93:511,
1980). Vitamin C's antioxidant function
prevents the oxidation of
LDL (the bad cholesterol), which has been shown to be instrumental in heart
disease. Chronic
subclinical deficiency of vitamin C may result in progressive oxidative damage which may lead to permanent
degenerative diseases in the heart (Mol Cell Biochem 1992 111:41-7). One puff on a cigarette can deplete the
plasma vitamin C content by as much as 50%. This is why the RDA for vitamin C intake for smokers is six times
that for non-smokers (Efstratopoulos AD & Voyaki SM J of Hypertension 1993 11(suppl 5):S112-113).
Clinical trials are now showing that vitamin C can lower blood pressure. It does this partially because of the
quenching of free radicals (Ceriello, et al. Clinical Science. 1991. 81:739-42). When Trout et al. supplemented
12 borderline hypertensives with 1 gram of vitamin C for six weeks, they demonstrated a significant reduction in
blood pressure. Since the basal fasting levels of vitamin C were more than adequate, the authors thought that
even larger reductions of blood pressure would be seen if the hypertensives studied did not have adequate
vitamin C to start (Trout, D.L. 1991. American Journal of Clinical Nutrition, 53:322S-25S).
Immune System
Given the many varied functions of vitamin C in the body, it is no surprise that it is also essential to
immunocompetence. It has been suggested that larger doses than the RDA may be useful in preventing the
formation of carcinogenic substances and in boosting immunity (Gastroenterology Clinics of North America
1990;19(2):p.483). Consumption of vitamin C has been inversely related to incidences of cancer in
epidemiological studies (Kromhout D. Essential micronutrients in relation to carcinogenesis. Am J Clin Nutr
1987;45:1361-7).
According to a recent report in Allergy and Imm. (Feb., 1993), Vitamin C has a "special influence" on enhancing
the immune response and warding off infection. Several studies of groups taking vitamin C show that it reduces
the longevity and severity of colds (Brit. J. Nutr. 67:3-16). One group, taking 600 mg supplements, had upper
respiratory tract infections reduced by 50% (Amer. J. Clin. Nutr. 57:170-74). Extra addition of vitamin C seems to
boost the immune system by increasing cellular immune functions and stimulating neutrophils
(immune-fighting cells). Patients receiving 1 gram vitamin C daily had improved neutrophil activity, resulting in a
dramatic reduction of infectious attacks (Anderson, R. Int J Vitam Nutr Res. Suppl. 23:23-34, 1982; Patrone, R,
Dallegri, F, Bonvivi, E, et al. Acta Vitaminol Enzymol. 4:163-68, 1982). Most importantly, vitamin C treated groups
don't feel as bad while they are sick. When this means less sick days and less interference with our daily lives,
vitamin C can help keep production levels up.
Asthma
Vitamin C is a
potent antioxidant which guards against the oxidant stress involved in the cause
and progression
of
asthma
(Hatch GE Am J of Clin Nutr 1995;61(suppl): p. 628S). Vitamin C decreases
histamine secretion and
also
blocks
production of the potent vasoconstrictive leukotrienes, which are known to be
involved in asthma (Werbach, M,
MD. Healing through nutrition, Harper
Collins Publishers, NY., p. 37).
General Well-being
A UCLA researcher, James Enstrom, says that 300 mg of vitamin C a day (half from supplements) will extend
the life of men 5 or 6 years longer than those getting only 25 mg. Enstrom claims that the same amount will add
two years to a woman's life (Fort Collins Coloradoan USA Weekend, Sept 30, 1994 p. 10). Symptoms such as
fatigue seen in vitamin C-depleted human volunteers may be the result of poor energy production due to
decreased carnitine biosynthesis (Muscle carnitine is thought to be a sensitive indicator of vitamin C status)
(Shils & Young, Modern Nutrition in Health and Disease., 7th ed. 1988. Lea & Febiger, Philadelphia, PA. p.422).
Contraindications/Toxicology
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High intake of vitamin C (>1,000 mg/day) may be a concern in people with kidney stones because of the
increased oxalic acid clearance through the kidneys due to vitamin C metabolism. It may be a concern in gout
because of increased levels of uric acid. It can cause diarrhea in some people with low bowel tolerances to
vitamin C, however most people can tolerate high doses well. Also, in those exhibiting iron overload disease,
supplementation can be harmful because vitamin C increases iron absorption.
The statements above have not been
evaluated by the FDA. The nutritional suggestions and research provided
are not intended to diagnose, treat, cure or prevent disease and should not be
used as a substitute for sound medical advice. Please see your health care
professional in all matters pertaining to your physical health. The
Professional Description, Professional Notes, Patient Instructions, and items
marked with an astrisk (*) are provided by the practitioner and are the sole
responsibility of the practitioner.Copyright © 1998-2002 Standard in Natural
Solutions, LLC.