Vitamin C, also called ascorbic acid, exists as either ascorbic acid
or ascorbate. It is a water-soluble vitamin and found in many
fresh fruits and vegetables. It is also found in many dietary
supplements. Vitamin C is vital for various physiologic
functions, such as synthesizing collagen and catecholamines and
carnitine and peptide synthesis . It is not manufactured in the
human body, and deficiency can cause scurvy. Oral vitamin C
is an antioxidant supplement for immune protection against
colds, flu, wound healing, cardiovascular health, and cancer
prevention. High-dose intravenous vitamin C is being studied
for treating cancer.
Food sources of vitamin C include- Kakadu plums, Acerola
cherries, Lemons, Brussel sprouts, Kale, Rosehips, Chilli peppers,
Guava, Sweet Yellow pepper, Thyme, Blackcurrant, Parsley,
Spinach, Kiwis, Litchis, Papaya, Strawberries, Oranges etc.
The advantages of vitamin C in fighting the common cold are
more assumed than evidenced by research. According to a
2007 review of many studies, including 11,306 participants,
vitamin C supplements did not decrease the rate of colds in
participants compared to the general population.
But the authors noted that vitamin C could benefit performance
athletes or people living in icy climates.
A review study of 2013 from Finland shows that vitamin C cannot
prevent colds but may reduce their course by up to about 8% in
adults and 14% in children with a daily dosage ranging from
1,000- to 2,000-milligram dose.
There is partial evidence that vitamin C supplements may slow
macular degeneration, an ageing-related eye disorder identified
by vision loss.
A 2001 study in Archives of Ophthalmology stated that people at
high risk of the disease who consumed 500 milligrams of vitamin
C per day and beta-carotene, vitamin E, and zinc delayed the
development of macular degeneration by 25% and the loss of
visual acuity by 15%.6.
A review from Tufts University concluded that taking 135
milligrams of vitamin C per day can stop some types of cataracts
and that doses of at least 363 milligrams could decrease the risk
of developing cataracts by not less than 57%..
High Blood Pressure
The advantages of vitamin C in treating high blood pressure have
long been lauded, although the actual effects are not nearly as
solid as once believed.
In a study of 2012 from Johns Hopkins University, it was
demonstrated that high doses of vitamin C of around 500
milligrams daily produced only slight declines in systolic blood
pressure but had an insignificant effect on diastolic blood
While scientists have yet to discover why this is, it is assumed
that strong doses of vitamin C have a slight diuretic effect that
supports removing excess fluid from the body and may help to
subside the pressure within your blood vessels.
Heart Disease and Cancer
Vitamin C is often erroneously complimented for its ability to
fight heart disease and cancer. Much of the misperception
has been kindled by vitamin C’s antioxidant properties.
While antioxidants appear to decrease the oxidative stress
linked with these diseases, there is little to no proof that vitamin
C supplements can directly influence the risk.
Amongst the clinical findings:
● A 10-year study including 14,641 men above the age of 50
showed that a 500-mg dose of vitamin C did not change
heart attacks or stroke rates compared to a placebo.
● A 5-year study comprising 77,721 older women and men also
showed no correlation between vitamin C consumption and
the risk of lung cancer
● A nine-year study including 8,171 older women explained
that 500 milligrams of vitamin C have no influence on
cancer rates compared to the general population.
Other benefits include:- treating vitamin C deficiency, cold,
bronchitis, wound healing, glaucoma, arthritis etc..
MECHANISM OF ACTION
Ascorbic acid works as an antioxidant to protect against
oxidative damage from free radicals. It inactivates nitric oxide,
enhances endothelium-dependent vasodilation, and acts by
different mechanisms depending on its plasma concentration.
Plasma concentrations of less than 0.1mM are accomplished
through oral consumption of dietary or supplemental forms.
At pharmacologic plasma concentrations ranging from 0.3 –
20mM through intravenous injection(IV), ascorbic acid is
oxidized to ascorbate radical. This radical acts as a prodrug
for hydrogen peroxide generation inside interstitial fluids. As a
result of which DNA damage and adenosine triphosphate (ATP)
depletion occur. Also, it triggers ataxia telangiectasia mutated
adenosine monophosphate-activated protein kinase (AMPK) and
inhibits the mammalian target of rapamycin (mTOR) in cancer
Another study claimed that ascorbate could direct
hematopoietic stem cell function and leukemogenesis. In
leukaemia, vitamin C compensated for Tet2 mutations to
recover normal function. Pharmacological ascorbate
selectively stimulated these cells in non-small-cell lung cancer
(NSCLC) and glioblastoma (GBM) cells. Ascorbate reduces
colon cancer cell proliferation by downregulating specificity
proteins. It also lessens ATP levels and induces autophagy and
cell death in prostate cancer cells. Preferred oxidative
cytotoxic effects on cancer cells may be due to the presence of
intracellular iron, copper, overexpression of sodium-dependent
vitamin C transporter 2 (SVCT-2), and an increase in p53
activity. Furthermore, high-dose vitamin C was known to
inhibit metastasis of breast cancer cells by inhibiting epithelial-
The oxidized form of ascorbic acid, such as dehydroascorbic
acid, may have cytoprotective effects by maintaining
mitochondrial membrane potential.
Common side effects include nausea, vomiting, heartburn,
Case reports for Oral Consumption of Vitamin C.
Patients with a history of kidney stones have shown
nephrolithiasis, acute renal failure or renal insufficiency and
increased oxalate kidney stone formation.
Hemolytic anaemia: May happen at extreme doses in patients
with G6PDH deficiency.
Severe cyanide poisoning: With concomitant use of three grams
of amygdalin and 4800mg of vitamin C per day.
Dental caries or eroded dental tooth: With extreme usage of
Case reports for Intravenous administration of Vitamin C.
The typical reaction includes increased urinary flow and
Isolated incidences include nausea, vomiting, unpleasant
fluttering in the abdomen, chills, and headaches.
Isolated incidences include confusion, increased leg edema
persisting for a few days.
DOSAGE and APPLICATION
Usually, Vitamin C is available as a dietary supplement in tablet,
capsule or powder form. For topical administration as a skin
cream and also Vitamin C can be administered intravenously.
● Children 0 – 6 months: 40milligrams per day
● Children 7 – 12 months: 50 milligrams per day
● Children 1 – 3 years: 15 milligrams per day
● Children 4 – 8 years: 25 milligrams per day
● Children 9 – 13 years: 45 milligrams per day
● Females 14 – 18 years: 65 milligrams per day
● Males 14 – 18 years: 75 milligrams per day
● Females of 19years and above: 75 milligrams per day
● Males of 19 years and above: 90 milligrams per day
● Pregnant females 14 -18: 80 milligrams per day
● Pregnant females 19 years and above: 85 milligrams per day
● Breastfeeding females 14 – 18: 115 milligrams per day
● Breastfeeding females 19 years and above: 120 milligrams
People who smoke should take an extra 35 milligrams per day.
Those diagnosed with vitamin C deficiency should take between
100 to 200 milligrams per day until blood levels are
Dosage for topical administration:-
● For erythema: A formulation containing 10% vitamin C, 2%
zinc sulfate, and 0.5% tyrosine used daily for eight.
● Skin wrinkles from sun damage: Usually, topical vitamin C
products are applied daily. Studies have used creams
containing 3% to 30% vitamin C. Do not use vitamin C
preparations to the eye or eyelids. Also, please avoid
contact with clothes or hair as it can cause
Dosage for IV administration:-
● For atrial fibrillation: 2 grams of vitamin C once or twice in
the day before going for heart surgery followed by 1-2
grams for 4-5 days daily after heart surgery.
● For decreasing pain after surgery: 3 grams of vitamin C for
the first 30 minutes of surgery has been used.
Be aware of consuming a large amount of Vitamin C as it can
● Repeated kidney stone formation
● Observed G6PDH deficiency
● Renal impairment or on chronic hemodialysis
For Special group:-
Pregnant and Lactating: Vitamin C is LIKELY SAFE for pregnant
or breastfeeding women when consumed orally in a
concentration of 2000 mg/day for women above 19 years old
and 1800 mg daily for women 14 – 18 years old or when given
administered intravenously or intramuscularly. Consuming
too much vitamin C during pregnancy can cause problems for
the newborn baby. It is POSSIBLY UNSAFE when ingested
orally in excessive amounts.
Children and infants: Vitamin C is LIKELY SAFE when
consumed orally. It is POSSIBLY UNSAFE when ingested
higher than 400 mg daily for children of age group 1 -3 years,
650 mg daily for children 4 to 8 years, 1200 mg daily for children
9 – 13 years, and 1800 mg daily for adolescents 14 to 18 years.
It is recommended that before taking Vitamin C, consult your
Iron: Ascorbic acid enhances iron absorption and modulates
storage and transport in the body. Notable in patients with
Chemotherapeutic drugs: Vitamin C may decrease the
effectiveness of some antineoplastic agents, including
vincristine, doxorubicin, methotrexate, etc..
Bortezomib: Ascorbic acid consumption lessens the activity of
bortezomib. In a clinical trial using these agents collectively,
the interaction is reduced by administering bortezomib and
ascorbic acid in the morning and evening, respectively.
Glutathione: Glutathione is an antioxidant that decreases the
pro-oxidant cytotoxic effects of ascorbic acid.
Beta-blockers: Ascorbic acid can improve the cardioprotective
effects of beta-blockers in post-bypass patients.
Paracetamol: When consumed simultaneously, vitamin C
increases the absorption of paracetamol in healthy volunteers
and may increase the risk of side effects.
KEYWORDS:- cancer, cancer, lung cancer, glioblastoma, colon
cancer, leukaemia, non-small cell lung cancer, prostate cancer,
breast cancer, metastasis, leukemogenesis
Hemilä, Harri, and Elizabeth Chalker. “Vitamin C for
preventing and treating the common cold.” Cochrane database of
systematic reviews 1 (2013).
Juraschek, Stephen P., et al. “Effects of vitamin C
supplementation on blood pressure: a meta-analysis of
randomized controlled trials.” The American journal of clinical
nutrition 95.5 (2012): 1079-1088.
Agathocleous, Michalis, et al. “Ascorbate regulates
haematopoietic stem cell function and leukaemogenesis.” Nature
549.7673 (2017): 476-481.