Also known as ascorbic acid, vitamin C was isolated in 1928. This vitamin serves as an excellent antioxidant and could protect various cells and tissues in the body, including brain cells and cells in the eye. The eye is highly susceptible to damage by sunlight, oxygen, various chemicals, and pollutants. Because of an aging Western world population and a continued depletion of ozone, having adequate antioxidants in the eye is very important, perhaps helping to protect against macular degeneration and deteriorating eyesight.
Vitamin C protects the immune system, reduces the severity of allergic reactions and helps to fight off infections. However the significance and beneficial effect in respect to human disease such as cancer, atherosclerosis, diabetes, neurodegenerative disease and metal toxicity however remains to be fully understood.
How
much is enough to benefit our cells?
Ever since Nobel Prize winner Linus Pauling
extolled the benefits of megadosing, the medical community has
been debating the optimal dosage intake of this vitamin. Although many doctors
stood firm for a long time asserting that the RDA of 60 mg for this vitamin
provided adequate benefits, more and more doctors are now realizing that higher dosages can confer
additional antioxidant benefits. However, the optimal daily intake of vitamin C
has not yet been determined, nor is it likely to be determined soon.
Nevertheless, we now suspect that excessive intake of vitamin C, except perhaps
in the therapy of a particular medical condition, may not be necessary.
A study published in the American Journal of Clinical Nutrition points that
large doses of ingested vitamin C may be excreted without being utilized. When
the dosage given to a group of healthy men was increased from 200
mg a day to 2,500 mg a day, blood levels increased only negligibly. Blood levels
of vitamin C generally reflect the levels found in the rest of the body.
Therefore, there seems to be a vitamin C dosage beyond which no further benefits
may be noticed.
MultiVit Rx -
High Quality Daily Vitamins and Minerals with Vitamin C and
Rose hips
This
MultiVit Rx product
has 500 mg of Vitamin C and rose hips per daily dose.
Q.
What's your opinion on the ideal daily dose of Vitamin C
and the benefit of taking such supplements?
A. If you ask a dozen
doctors this question, you are likely to get a dozen different answers. I would
say that for those who have an excellent diet with plenty of fresh fruits
(including citrus) and vegetables, they many not need to take any vitamin C
supplements. For those whose diet is not ideal, it would seem reasonable to take
between 50 to 300 mg once or twice a day, preferably a formula that includes
bioflavonoids.
Rev Prat. Oct 2013. Vitamin C is a water soluble vitamin which is mainly fresh fruits and vegetables foodborne. Deficiency is most often due to a lack of daily amount. Scurvy is characterized by the occurrence of fatigue, myalgia, arthralgia, purpura, bleeding disorders, and later by dental manifestations. Biological signs are nonspecific: anemia, hypocholesterolemia, hypoalbuminemia. Clinical suspicion is confirmed by the decrease in ascorbic acid level (< 2 mg/L). It must be interpreted in light of the acute phase reactants. The treatment is the administration of 1 g of vitamin C per day for 15 days.
Eyesight Rx
Benefits Healthy Vision
Supplement Facts:
Vitamin C - 15 mg
Citrus bioflavonoids (eriocitrin,
hesperidin,
flavonols,
flavones,
flavonoids, naringenin, and
quercetin)
Mixed carotenoids (alpha carotene,
astaxanthin,
beta carotene
is a popular carotenoid,
beta cryptoxanthin,
Lutein is commonly found in
eye formulas,
Lycopene is found in high amounts in
tomato and watermelon,
Zeaxanthin)
Bilberry
extract (Vaccinium myrtillus)
Eyebright
extract (Euphrasia officianales)
Jujube extract (Zizyphus jujube)
Ginkgo biloba
(Ginkgo biloba)
Suma extract (Pfaffia paniculata)
Mucuna pruriens
extract, see also Mucuna-Pruriens supplement information.
Cinnamon (Cinnamomum zeylanicum)
Lycium berry extract (Lycium Barbarum)
- also known as Goji
Berry extract supplement.
Sarsaparila (Sarsaparilla Smilax)
Alpha lipoic acid
antioxidant that helps maintain visual acuity
Testimonial received in 2018
I would also like to mention a favorable reaction to three other
supplements. Ever since I was a kid, there was no such thing as a simple
cold or flu. I would always get so sick that I would be incapacitated
for a month or more followed by a bacterial infection and antibiotics. I
learned that at the first sign of a cold, I would take 100mg of zinc and
50,000 IU of vitamin D every day until I felt no symptoms (2-4 days).
This worked in 13 of the last 15 years. Well, I am coming off a short
bout of flu. This time, I took 10 grams of buffered Vitamin C with a
product called C-Salts. I cannot tell you what a difference this made. I
go hit hard on a Wednesday. I took the two servings of 5 grams that day.
While I felt no better the next day in total, most of my headache was
gone and 90% of the muscle aches were gone. By Friday, that feeling of I
want to lay down when standing was largely gone, but my cough was a
little worse. On Saturday, I did a lot around the house, and by Sunday
(only 4-5 days of feeling bad) I was feeling pretty good. Unheard of, in
my case. I am still coughing a little (sixth day) , but finding little
need to blow my nose. The vitamin C kept the mucus clear the whole time
which was probably why my chest has remained clear throughout.
Atrial
fibrillation
Oral vitamin C appears to cut the risk of early recurrence of
atrial fibrillation after patients undergo electrical cardioversion.
It also appears to reduce the low-level inflammation that
accompanies this condition. Early atrial fibrillation recurrence after
cardioversion may be due to electrophysiological changes in the chambers
of the heart, known as atrial remodeling. To investigate whether vitamin C
can reduce atrial fibrillation recurrence, a research team randomized 44
consecutive patients who had undergone cardioversion for persistent atrial
fibrillation to standard therapy plus oral vitamin C or standard treatment
only. Patients given the vitamin received a 2-gram loading dose 12 hours
before cardioversion and 500 mg twice daily for the next seven days. One
(4.5 percent) of the patients given vitamin C had a relapse of atrial
fibrillation, while eight (36.3 percent) of patients not given the vitamin
did.
The researchers also found that white blood cell levels and fibrinogen
levels fell significantly in the group given vitamin C, but did not drop
in the control patients. Markers of inflammation were also significantly
higher among patients who had a recurrence of atrial fibrillation,
compared with those who did not. SOURCE: International Journal of
Cardiology, 2005.
Cancer treatment
Large doses of intravenous vitamin C have the potential to boost
chemotherapy's ability to kill cancer cells, ovarian cancer, according to new laboratory
research involving human cells and mice. Feb. 5, 2014, Science Translational
Medicine.
Bladder cancer
Clin Epigenetics. 2018. Vitamin C increases 5-hydroxymethylcytosine level and
inhibits the growth of bladder cancer.
Vitamin C treatment reduces elevated
C-reactive protein.
Free Radic Biol Med. 2008. University of
California, Berkeley, CA, USA.
Treatment with vitamin C but not vitamin E significantly reduced CRP
among individuals with CRP >/=1.0 mg/L. Among the obese, 75% had CRP >/=1.0
mg/L.
Cataract benefit, eye health
Acta Ophthalmol. 2015. Association of vitamin C with the risk of age-related
cataract: a
meta-analysis.
Vitamin C benefit for
gout
Supplementation may lower
uric acid levels which
could be beneficial in those who have
gout.
Heart disease
A major study has found that taking supplemental
Vitamin C (more than 700 mg. a day may be of benefit by reducing the rate of coronary
heart disease. However, taking additional Vitamin E or carotenoids showed no
reduced risk. The study, which was published in the American Journal of Clinical
Nutrition, was an epidemiological study, which suggests a relationship between
two or more things but does not prove that one thing causes another.
Heart surgery benefit
Intravenous vitamin C before elective percutaneous coronary intervention (PCI)
improves microcirculatory reperfusions. This finding indicates oxidative stress
is to blame for the impaired myocardial reperfusion that follows up to 40% of
PCI cases. Dr. Stefania Basili of the University of Rome "La Sapienza" randomly
assigned 56 patients with stable angina undergoing elective PCI to receive 1 g
vitamin C, infused at 16 mg/min during the hour before the procedure, or
placebo. Rates of Thrombolysis in Myocardial Infarction (TIMI) myocardial
perfusion grade < 2 were 89% in the placebo group and 86% in the intervention
group at baseline. After PCI, however, rates were 32% in the placebo group vs 4%
in the vitamin C group.Also, 79% of vitamin C patients achieved TIMI perfusion
grade 3 - or complete microcirculatory perfusion - compared to 39% of placebo
patients.To confirm the antioxidant effect of vitamin C, the authors also
monitored plasma levels of 8-hydroxy-2-deoxyguanosine and 8-iso-prostaglandin
F-2-alpha as markers of oxidative stress and inflammation. At 60 minutes after
balloon inflation, levels had increased significantly in the placebo group but
had decreased significantly in the patients who received vitamin C. The authors
point out that vitamin C has a short half-life, which means that any impact on
reperfusion "would probably be a consequence of a short-term effect on arterial
dilation." J Am Coll Cardiol Intv 2010.
Topical Vitamin C
cream
Cosmeceuticals containing antioxidants are among the most popular
antiaging
remedies. Topically applied antioxidants exert their benefits by offering
protection from damaging free radicals produced when skin is exposed to
ultraviolet light or allowed to age naturally. Vitamin C is a naturally
occurring potent water-soluble antioxidant. Accordingly, it has been
incorporated into a variety of cosmeceuticals designed to protect and
rejuvenate photoaged skin.
Vitamin C cream or lotion products sold online
Avalon Organics, Intense Defense with Vitamin C Renewal Cream, 2 oz (57 g)
Beauty Without Cruelty, Hand and Body Lotion, Vitamin C, with CoQ10, 8.5 fl oz
By injection
When vitamin C is ingested by mouth, plasma and tissue concentrations are
tightly controlled by at least 3 mechanisms in healthy humans: absorption,
tissue accumulation, and renal reabsorption. A 4th mechanism, rate of
utilization, may be important in disease. With ingested amounts found in foods,
plasma concentrations do not exceed 100 mmol/L. Even with supplementation
approaching maximally tolerated doses, ascorbate plasmaconcentrations are always
<250 mmol/L and frequently <150 mmol/L. By contrast, when ascorbate is i.v.
injected, tight control is bypassed until excess ascorbate is eliminated by
glomerular filtration and renal excretion. With i.v. infusion, pharmacologic
ascorbate concentrations of 25–30mmol/L are safely achieved. Pharmacologic
ascorbate can act as a pro-drug for hydrogen peroxide (H2O2) formation, which
can lead to extracellular fluid at concentrations as high as 200 mmol/L.
Pharmacologic ascorbate can elicit cytotoxicity toward cancer cells and slow the
growth of tumors in experimental murine models. Adv Nutr 2011.
Liposomal?
Q. I would like to know your opinion on the nanotechnology of liposomal
Vitamin C. Is this form really absorbed much more efficiently than other types
of vitamin C? Is the nano-bio technology safe for use?
A. I do not see any advantage using the liposomal form of vitamin
C.
Smoking
Vitamin C supplements can help reduce the high rate of
vitamins
E
depletion that occurs in smokers.
Vitamin C overdose - side effect of too much
Vitamin C is helpful for many conditions and it is one of the safest
supplements on the market. High doses are taken at the onset
of a cold. I have personally taken up to 8 grams at one time
with the only side effects being nausea. It is very difficult to overdose. Another symptom of overdose is diarrhea and some
people report other gastrointestinal disturbances. I am not aware of any
fatalities from vitamin C overdose. Too much vitamin C is not necessary,
and any dosage above 500 or 1000 mg a day may not provide any further
benefit.
Excess intake of vitamin C from supplements is usually excreted harmlessly in the urine, but in patients with kidney failure, it is retained and can combine with oxalate to form crystals that deposit in the kidney tubules. High-dose vitamin C supplement use should be avoided in patients with kidney failure.
Vitamin C intravenously and
Cancer
High-dose intravenously administered vitamin C
led to longer-than-expected survival in three patients with
advanced cancer. Two of the three patients are
still alive without evidence of disease.
In the three cases described in the Canadian Medical Association Journal,
vitamin C was given intravenously at doses ranging from 15 to 65 grams to
produce plasma concentrations that cannot be achieved by taking it
by mouth.
The first patient was a 51 year-old-women with advanced renal cancer who
underwent surgical removal of the kidney but had evidence that the cancer
had spread to the lungs. She received IV vitamin C 65 grams twice a week
for 10 months, in combination with other alternative therapies. Repeat
chest x-ray revealed one small spot, assumed to be a scar. Five years
later, new lung masses were detected. The patient again received
intravenous vitamin C, with unsuccessful results.
The second patient, a 49-year-old man, had bladder cancer with multiple
satellite tumors. He received IV vitamin C 30 grams twice a week for three
months, followed by 30 grams vitamin C once every 1-2 months for four
years. Nine years after diagnosis, the patient is in good health, without
signs of disease.
Case three was a 66-year-old woman with lymphoma invading spinal muscle
and bone. She received IV vitamin C 15 g twice weekly for 7 months, then
15 g every 2-3 months for about one year. Ten years after diagnosis, the
patient is in good health. It appears all three patients survived for
longer than expected for the types and stages of cancers that they had. Canadian Medical Association Journal, 2006.
Research
If a pregnant woman's waters break too early, her unborn baby can be put
in danger of complications. The risk of this happening, however, may be reduced
if she takes daily supplements of 100 mg vitamin C after the half-way point of
pregnancy.
The effects of vitamin C supplementation on serum
concentrations of uric acid: results of a randomized controlled trial.
Arthritis Rheum. 2005.
Supplementation with 500 mg/day of
vitamin C for 2 months reduces serum uric acid, suggesting that vitamin C might
be beneficial in the prevention and management of gout and other urate-related
diseases.
Older women with diabetes who take high
doses of vitamin C for the sake of their hearts may be doing more harm than
good, new research suggests. The study, which followed nearly 2,000
postmenopausal women with diabetes for 15 years, found that those who took heavy
doses of vitamin C supplements -- 300 milligrams (mg) a day or more -- were
roughly twice as likely to die of heart disease or stroke compared with women
who took no supplemental C. The researchers did find statistically weak evidence
that lower supplement doses -- up to 99 mg per day -- curbed the risk of
cardiovascular death, and high intakes of vitamin C from food were not related
to a greater risk of death from cardiovascular causes. The findings appear in
the November 2004 issue of the American Journal of Clinical Nutrition.
Researchers who set out to prove that a mega-dose of
vitamin C can improve exercise performance in fact showed it has no effect at
all. The vitamin, given intravenously to younger and older volunteers, did
nothing to help them work harder on a treadmill, the team at the University of
Colorado found. But the vitamin, given as
ascorbic acid, did reduce oxidative
stress - chemical damage done to cells and proteins in the body, the researchers
found. "We did see a decrease in oxidative stress with large doses of vitamin C,
but this decrease didn't improve aerobic abilities either for younger or older
subjects," said Christopher Bell, now at Colorado State University, who led the
research.
We received this email: Dear Dr. Sahelian, I was very
pleased to see your excellent "Vitamin C Research Update" on Chris Bell's
"mega-dose" (as well as "chronic" dose study on potential effects on endurance
exercise. However, it would be great if you could note that the Vitamin C study
appeared in the Journal of Applied Physiology, published by the American
Physiological Society. Best wishes, Mayer R. Resnick, Communications Officer,
American Physiological Society, Bethesda, MD.
Comprehensive study on vitamin C equivalent antioxidant
capacity (VCEAC) of various polyphenolics in scavenging a free radical and its
structural relationship.
Crit Rev Food Sci Nutr. 2004.
Department of Food Science and Technology, Cornell University, Geneva, New
York
Antioxidant capacity for a wide range of natural or synthetic
polyphenols
was comprehensively evaluated by vitamin C equivalent antioxidant capacity (VCEAC)
assay using free blue/green ABTS radicals. The polyphenolics tested are grouped
into the following categories: vitamins (beta-carotene, alpha-tocopherol,
vitamin A, and vitamin C), phenolic acids (benzoic acid, phenylacetic acid,
cinnamic acid, and their derivatives),
flavonoids (anthocyanidin, flavanol,
chalcone, flavanone, flavone, flavonol, isoflavone, and their derivatives),
synthetic food additives (BHA, BHT, TBHQ, and PG), and other miscellaneous
polyphenolics (ellagic acid, sesamol, eugenol, thymol, etc.). A positive linear
relationship between VCEAC and the number of free OH groups around the flavonoid
framework was found, whereas, for phenolic acids, the linear relationship was
not as good as with the flavonoid aglycones. Groups of chemicals having
comparable structures generally showed similar trends. Synthetic antioxidant food additives (BHA, TBHQ, and BHT)
conventionally used in the food industry were less effective antioxidants than
ascorbic acid.
Bone Mineral Density in Postmenopausal Women
J Bone Miner Res 2001. The purpose of this study was to evaluate
the independent relation of daily vitamin C supplement use with BMD in a
population-based sample of post menopause women.
Subjects were 994 women from a community-based cohort of whom 277 women were
regular vitamin C supplement users. Daily vitamin C supplement intake ranged from 100 to 5,000 mg; the mean daily
dose was 745 mg. Average duration of use was 12 years. Women who took vitamin C plus calcium and estrogen had the highest BMD at
the femoral neck, total hip, ultradistal radius, and lumbar spine. Vitamin C supplement use appears to have a beneficial
effect on levels of BMD, especially among postmenopausal women using concurrent
estrogen therapy and calcium supplements.
Emails
Q. For what it is worth, I have megadozed on vitamin C for
nearly forty years. From age 40 to age sixty, when I retired, I walked fifteen
miles a day with a heavy satchel on my back delivering mail to some 549 houses
on a foot route (no vehicle) in every type of weather. I averaged about 10,000
milligrams of vitamin C a day during those years. Today at 68 I take no
precription drugs and am in apparently good health, except for a degree of
arthritis in my lower back, likely a result of walking 75,000 miles over twenty
years. Today I average about 14,000 milligrams of vitamin C a day.
Q. Is there an
acne vitamin, I mean
does vitamin C help acne?
A. We are not aware of any vitamin supplements that help improve
acne. Diet is the most
important.
Q. I was
informed by various sources that natural vitamins are better than synthetic and
donate photogenic energy that only occurs in live source materials. Natural
vitamins cost so much more and have lower dosages. Isolated vitamins are missing
all the elements found in whole food source derivatives. Can you shed some light
in this and maybe help save me money at the same time?
A. The chemical structure of a vitamin, whether extracted from
nature such as a plant, or whether made in a laboratory, will be the same and
have the same exact role in the body. There are times, though, that an extract
of a vitamin from a plant could contain additional beneficial substances. In the
case of vitamin C, whether it is from nature or made in the lab, it will have
the same effect. But there are extracts of vitamin C that come from certain
fruits that will also contain substances known as bioflavonoids that have a lot
of health benefits. In the latter case, the vitamin bottle supplement fact panel
will indicate that there are bioflavonoids in addition to vitamin C.
Additional Antioxidants to consider.
Aceytylcysteine is
a powerful antioxidant used in hospitals also.
Acetyl l Carnitine
is best taken less than 300 mg since higher amounts can cause nausea and
restlessness.
CoQ10 30 mg can be used
daily, higher amounts such as 50 or above should be taken every other day.
Choline which helps form acetylcholine and phospholipids
Ester-C, Vitamin C 500 mg, 180 Tablets
Note:
the paragraph below is provided by the manufacturer. In my
opinion, I don't really see the benefit of Ester C over vitamin C except for bioflavonoids and calcium.
The
Key to the Power of Vitamin C:
ESTER -
C is a form of vitamin C ascorbate containing essential C metabolites. Unlike ordinary vitamin C, Ester-C is produced through an exclusive
water based manufacturing process, providing anon acidic form that
is gentle on your stomach. ESTER-C also has added bioflavonoids which play a role in maintaining good health.
Amount per tablet:
Vitamin C - 500 mg - 830% Daily value
(as calcium ascorbate Ester-C
Calcium - 90 mg - 10% DV as calcium ascorbate
Ester-C
Bioflavonoid Complex - 130 mg
Rutin - 36 mg
Hesperidin Complex - 35 mg
Q. What's your opinion of Ester-C vitamin ?
A. Honestly I just don't see the necessity of taking
Ester-C vitamin as opposed to regular vitamin C. I know Larry King has been promoting
Ester C on
radio, but what does he know about optimal health and nutrition? He doesn't even
ask though questions to his political guests let alone asking the company he is
the spokesperson for the easy question: What is the research that says Ester C
vitamin is preferable to regular vitamin C? Most people who take a vitamin C
supplement ingest as much or more vitamin C than they need if the supplement has
at least 200 mg of vitamin C. And most vitamin C supplement tablets are often
250 mg or 500 mg. There are no long term human studies that say Ester C is a
healthier option than regular C. However, if there are bioflavonoids in Ester C
preparations, that could offer some additional benefits, but then again it's
cheaper to buy a vitamin C supplement with bioflavonoids as opposed to Ester C.
Chewable vitamin C could cause tooth enamel erosion if
left in the mouth too long. I am not sure whether Ester C vitamin would have the
same effect on tooth enamel.
Here's a study on Ester C that supports my viewpoint:
Pharmacokinetics in dogs after oral administration of two different forms of
ascorbic acid.
Res Vet Sci. 2001. Department of Pharmacology, School of
Pharmacy, University of Oslo.
The dog is able to synthesise vitamin C, but is frequently given the vitamin
in an attempt to improve health and performance. The pharmacokinetics of vitamin
C in this species, however, are not well studied. Using a selective analytical
method and careful stability control, the pharmacokinetics of orally given
vitamin C was studied in 20 dogs, at two dosage levels (15 and 50 mg kg(-1)) and
with two forms of supplement [crystalline vitamin C and the vitamin C product
Ester-C (Inter-Cal Corp., Prescott, AZ, USA)]. After oral administration, a
rapid increase was found in the plasma level of vitamin C, indicating a possible
intestinal active transport mechanism in this species. The obtained C (max) and
AUC values were found to increase in a non-linear fashion when the dose of
vitamin C was increased. The pharmacokinetic modeling of the elimination of
vitamin C was made difficult by a pronounced secondary peak appearing after
about 9 hours. The comparison of crystalline vitamin C and Ester-C did not
indicate any significant differences in pharmacokinetic parameters between the
two preparations of the vitamin.
Doctor's Best, Best Vitamin C, 500 mg, 120
Veggie Caps
Buy Vitamin C 500
mg, 120 Capsules
Supplement Facts | ||
Serving Size: 1 capsule | ||
Servings Per Container: 120 servings | ||
Amount Per Serving | % Daily Value | |
Vitamin C (as Quali-C ascorbic acid) | 500 mg | 833% |
† Daily Value not established. |