VITAMIN C

Vitamin C works as an antioxidant to protect your cells against free radicals, which may play a role in heart disease, cancer and other diseases.
Vitamin C helps maintain the health of your cells, immune system, bones and blood vessels.
Vitamin C prevents and treats low Vitamin C levels in your body.

CAS Number: 50-81-7
EC Number: 200-066-2
E Number: E300
Molecular Formula: C₆H₈O₆
Molecular Weight: 176.12 g/mol

SYNONYMS:
l-ascorbic acid, ascorbic acid, ascorbate, IUPAC, l-threo-Hex-2-enono-1,4-lactone ((R)-3,4-Dihydroxy -5-((S)- 1,2-dihydroxyethyl)furan-2(5H)-one), Ascorbic Acid, L-Ascorbic Acid, Antiscorbutic Factor, Vitamin C, Antiscorbic Vitamin, L- Ascorbic Acid (Vitamin C), L-threi-hex-enoic acid, gamma lactone, 3-keto-L-gulofuranolactone, L-3-ketotreohexuronic acid lactone, 3-oxo-L-gulofuranolactone, Vitamin C, L-Xyloasuribic acid, Ascorbic Acid, L-Ascorbic Acid, Vitamin C, E300, L-(+)-Ascorbic Acid, Antiscorbutic Vitamin, L-threo-Hex-2-enonic Acid γ-Lactone, 2,3-Didehydro-L-threo-Hexono-1,4-Lactone, 3-Keto-L-gulofuranolactone, Cebion, Cantan, Redoxon

Vitamin C also functions as an antioxidant.
Vitamin C is a water-soluble vitamin found in citrus and other fruits, berries and vegetables.
Vitamin C is also a generic prescription medication and in some countries is sold as a non-prescription dietary supplement.

Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters.
Vitamin C is required for the functioning of several enzymes and is important for immune system function.

Vitamin C may be taken by mouth or by intramuscular, subcutaneous or intravenous injection.
Vitamin C is a water-soluble nutrient with numerous functions in the body.
Diagnostic testing: Vitamin C content in plasma is used to determine vitamin status.

Vitamin C helps boost the immune system, supports collagen production, and aids in wound healing.
Vitamin C acts as an antioxidant to protect cells from damage caused by free radicals.
However, humans cannot synthesize Vitamin C on their own.

Therefore, to meet the recommended intake of Vitamin C, it is essential to obtain it from foods or supplements to maintain good health.
Vitamin C is a substance the body needs to form blood vessels, cartilage, muscle and collagen in bones.
The body also needs Vitamin C for healing.

Vitamin C helps protect cells from damage.
Substances like Vitamin C that protect against cell damage are called antioxidants.
The damage comes from molecules the body makes when Vitamin C breaks down food, has contact with tobacco smoke, or is exposed to the sun's rays or other sources of harm.

Vitamin C is an antioxidant medication that comes in chewable tablets to prevent low Vitamin C levels.
Vitamin C is the generic descriptor for compounds having antiscorbutic activity.
Ascorbate is found widely in fruits and vegetables.

Fruits such as blackcurrants, guava, citrus, and kiwi fruit and vegetables such as broccoli and sprouts are good sources.
The Australian bush food terminalia ferdinandiana is the richest source.
However, because of their longer periods of availability, vegetables often contribute more ascorbate to the diet than fruits.

In Australia, some 40% of the Vitamin C comes from vegetables and 19% from fruits and a further 27% from fruit and vegetable juices.
Vitamin C is very labile and its content in foods varies.
Vitamin C content can be affected by season, transport, shelf life, storage time, cooking practices and chlorination of water.

Cutting, bruising, heating and exposure to copper, iron or mildly alkaline conditions can destroy ascorbate.
Vitamin C can also be leached into water during cooking.
Vitamin C is an essential vitamin that must be consumed in the diet.

Good sources include fresh fruits and vegetables, especially citrus fruits.
Vitamin C is needed for the body to develop and function properly.
Vitamin C plays an important role in immune function.

Most experts recommend getting Vitamin C from the diet rather than taking supplements.
Fresh oranges and fresh-squeezed orange juice are good sources.
Vitamin C is a water-soluble vitamin.

Vitamin C is needed for normal growth and development.
Vitamin C is a water-soluble vitamin that dissolves in water.
Leftover amounts of Vitamin C leave the body through the urine.

Although the body keeps a small reserve of these vitamins, they have to be taken regularly to prevent a shortage in the body.
Ironically, Vitamin C was first isolated from an animal source.
In 1928, the legendary Hungarian biochemist Albert Szent-Györgyi, then a student at the University of Cambridge (UK), extracted what he called “hexuronic acid” from the adrenal cortices of oxen.

He and colleague Walter Norman Haworth later isolated the molecule from lemons and paprika.
Szent-Györgyi was awarded the Nobel Prize in Physiology or Medicine in 1937; the same year, Haworth received the prize in chemistry.
In 1933, R. G. Ault at Birmingham Chemical Laboratories (UK), along with Haworth and others, was the first to report a synthesis of L- and D-Vitamin C.
(The D-enantiomer does not exist in nature and has no known uses.)

That same year, Polish chemist Tadeusz Reichstein and colleagues at ETH Zürich developed a robust chemical/microbial process for producing Vitamin C from D-glucose.
Their multistep process was the predominant manufacturing route until the 1960s, when Vitamin C was displaced by a two-step fermentation process developed in China.

Reichstein was awarded the 1950 Nobel Prize in Physiology or Medicine, but for his work on cortisone, not Vitamin C.
Vitamin C is essential for human nutrition.
Vitamin C is a cofactor that permits several enzymes to function properly; it plays a role in the immune system; and it is an antioxidant.

Vitamin C deficiency causes the disease scurvy, which, if not treated, results in decreased red blood cell production and excessive bleeding.
Vitamin C was the topic of much controversy in the 1970s.
Double Nobel prizewinner Linus Pauling advocated the consumption of large doses of the vitamin as a way to compensate for the body’s inability to produce enough of it for optimum health.

Specifically, Pauling espoused taking 2.5 g or more Vitamin C per day for general health and to prevent or treat the common cold.
He and others also contended that doses as great as 10 g/day helped prevent or cure heart disease and cancers.
The so-called Vitamin C megadose theory has been largely discredited.

Vitamin C is a naturally occurring organic compound known as Vitamin C, widely used in skincare and food industries for its antioxidant properties.
Vitamin C is a powerhouse ingredient celebrated for its antioxidant properties, skin-brightening effects, and role in collagen synthesis.
Vitamin C is a water-soluble organic compound with the chemical formula C6H8O6.

Vitamin C is naturally found in citrus fruits, berries, and green vegetables and is widely used across industries for its antioxidant properties, which help neutralize free radicals, protect cells, and support immune health.
Vitamin C is a white to very pale yellow crystalline powder with a pleasant sharp acidic taste.

Vitamin C is almost odorless.
Vitamin C has a six carbon compound related to glucose.
Vitamin C is found naturally in citrus fruits and many vegetables.

Vitamin C is an essential nutrient in human diets, and necessary to maintain connective tissue and bone.
Vitamin C's biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways.
Vitamin C is considered an antioxidant.

Vitamin C is a metabolite found in or produced by Escherichia coli.
Vitamin C has been reported in Camellia sinensis, Talaromyces islandicus, and other organisms with data available.
Vitamin C is a natural water-soluble vitamin.

Vitamin C is a potent reducing and antioxidant agent that functions in fighting bacterial infections, in detoxifying reactions, and in the formation of collagen in fibrous tissue, teeth, bones, connective tissue, skin, and capillaries.
Found in citrus and other fruits, and in vegetables, Vitamin C cannot be produced or stored by humans and must be obtained in the diet.

Vitamin C is a small molecule drug with a maximum clinical trial phase of IV (across all indications) that was first approved in 1985 and has 6 approved and 96 investigational indications.
Vitamin C has a six carbon compound related to glucose.

Vitamin C is found naturally in citrus fruits and many vegetables.
Vitamin C is an essential nutrient in human diets, and necessary to maintain connective tissue and bone.
Vitamin C's biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways.

Vitamin C is considered an antioxidant.
Vitamin C is the name of the chemical structure for pure vitamin C, the same vitamin C you find in citrus, bell peppers, strawberries, and other fruits and vegetables.

Vitamin C is essential to proper nutrition and does more than boost your immune system.
When used topically is an antioxidant that will help protect the skin to reduce damage from free radicals generated by sun exposure and other environmental factors that lead to signs of aging.

Using pure Vitamin C for skin can also help to reduce the appearance of wrinkles and fine lines by restoring elasticity and firmness lost with aging.
Vitamin C is a substance the body needs to form blood vessels, cartilage, muscle and collagen in bones.
The body also needs Vitamin C for healing.

Also called Vitamin C, Vitamin C helps protect cells from damage.
Substances like Vitamin C that protect against cell damage are called antioxidants.
The damage comes from molecules the body makes when Vitamin C breaks down food, has contact with tobacco smoke, or is exposed to the sun's rays or other sources of harm.

These molecules are called free radicals.
They may play a role in heart disease, cancer and other conditions.
Vitamin C also helps the body absorb and store iron.

The body doesn't make Vitamin C.
Vitamin C comes from the diet.
Sources of Vitamin C include berries, cantaloupe, tomatoes, peppers, potatoes, cabbage, Brussels sprouts, broccoli, spinach and citrus fruits, such as oranges.

Vitamin C also comes as a supplement, mainly in the form of capsules you swallow and tablets you chew.
Most people get enough Vitamin C from a good diet.

Not having enough Vitamin C, called deficiency, is more likely in people who: 
*Smoke or are around secondhand smoke.
*Have certain conditions of the digestive tract or certain types of cancer.
*Have a diet that doesn't include enough fruits and vegetables.

Not having enough Vitamin C can lead to a condition called scurvy.
Scurvy causes anemia, bleeding gums, bruising and poor wound healing.

The recommended daily amount of Vitamin C is 90 milligrams for adult men and 75 milligrams for adult women.
If you take Vitamin C for its antioxidant effects, the supplement might not be as good for you as natural Vitamin C that's in food.

USES and APPLICATIONS of VITAMIN C:
As a therapy, Vitamin C is used to prevent and treat scurvy, a disease caused by Vitamin C deficiency.
Vitamin C comes in extended-release (long-acting) capsules and tablets, lozenges, chewable tablets, chewable gels (gummies), and liquid drops to be given by mouth.

Vitamin C usually is taken once a day or as directed by your doctor.
Vitamin C is available without a prescription, but your doctor may prescribe Vitamin C to treat certain conditions.
Follow the directions on the package or on your product label or doctor's instructions carefully, and ask your doctor or pharmacist to explain any part you do not understand.

Take Vitamin C exactly as directed.
Do not take more or less of Vitamin C or take it more often than recommended by your doctor.
Vitamin C may take up to 4 weeks for symptoms of scurvy to improve.

Vitamin C supplements are available alone and in combination with other vitamins.
Vitamin C is used as a dietary supplement when the amount of Vitamin C in the diet is not enough.
People most at risk for Vitamin C deficiency are those with a limited variety of food in their diet, or who have intestinal malabsorption problems from cancer or kidney disease.

Vitamin C is also used to prevent and treat scurvy (a disease that causes fatigue, gum swelling, joint pain, and poor wound healing from a lack of vitamin C in the body).
Vitamin C is in a class of medications called antioxidants.

Vitamin C is needed by the body to help wounds heal, to enhance the absorption of iron from plant foods, and to support the immune system.
Vitamin C works as an antioxidant to protect your cells against free radicals, which may play a role in heart disease, cancer and other diseases.
Vitamin C helps maintain the health of your cells, immune system, bones and blood vessels.

Vitamin C prevents and treats low Vitamin C levels in your body.
Vitamin C plays an important role in maintaining the health of your blood vessels, bones, and immune system.
Vitamin C can also help wounds heal.

Vitamin C is an antioxidant, which helps to protect your cells.
Vitamin C may be used for other purposes; ask your health care provider or pharmacist if you have questions.
Vitamin C is a reducing agent (antioxidant) and it is likely that all of its biochemical and molecular functions relate to this property.

In humans, Vitamin C acts as an electron donor for eight enzymes, of which three are involved in collagen hydroxylation (including aspects of norepinephrine, peptide hormone and tyrosine metabolism) and two are involved in carnitine biosynthesis.
Vitamin C is found in high concentrations in gastric juices where it may prevent the formation of N-nitroso-compounds, which are potential mutagens.

Vitamin C has been shown to protect lipids in human plasma and low density lipoprotein in ex vivo experiments against oxidative damage.
Vitamin C also interacts with other nutrients.

Vitamin C aids in the absorption of iron and copper, the maintenance of glutathione in the reduced form, the regeneration, or sparing, of alpha-tocopherol and the stabilisation of folate.
Intestinal absorption of Vitamin C occurs through a sodium-dependent active transport process that is saturable and dose dependent.

Kallner et al showed that some 70-90% of usual intake is absorbed and that absorption fell to 50% or less with increasing doses above 1 g/day.
Dose-dependent absorption and renal regulation of ascorbate allow conservation of Vitamin C in the body during periods of low intake and regulation of plasma levels at high intakes.

There is a sigmoidal relationship between intake and plasma concentration of Vitamin C.
Newton et al showed that for intakes up to 30 mg/day, plasma concentrations are about 11 µmol/L (or 0.2 mg/dL).
Above this intake, plasma concentrations increase steeply to 60 µmol/L and plateau at 80 µmol/L, the renal threshold.

Levine et al found that the steep portion of the plasma concentration curve occurred with a daily dose of Vitamin C of between 30 and 100 mg and that complete saturation occurred at 1,000 mg daily.
Close to steady states, plateau concentrations are reached above 200 mg/day.

Absorption is also to some extent dependent on the dosing regimen of Vitamin C.
For example, there would be better absorption with 250 mg as supplements taken four times daily than 1,000 mg taken once daily.
High levels of Vitamin C are found in the pituitary and adrenal glands, leukocytes, eye tissues and fluids and the brain.

The biologic half-life of Vitamin C is 8-40 days and catabolic turnover varies widely, averaging 2.9% over a wide range of intakes.
A body pool of less than 300-400 mg is associated with the symptoms of scurvy.
At saturation, the whole body content in males is about 20 mg/kg or 1,500 mg.

Plasma Vitamin C concentrations are reduced by 40% in male smokers.
This may be partly due to smokers tending to eat less fruits and vegetables, but after correcting for intakes of fruit and vegetables, smokers still show lower plasma ascorbate than non-smokers.

The metabolic turnover of ascorbate is markedly accelerated in smokers.
Vitamin C deficiency causes scurvy, symptoms of which include skeletal and vascular lesions with gingival changes, pain in the extremities, haemorrhage, oedema, ulcerations and death.

In adults, clinical signs occur at intakes of 7-8 mg/day or less.
In infantile scurvy, the changes are mainly at the sites of active bone growth and include a pseudoparalysis of the limbs.
Historically, Vitamin C was used for preventing and treating scurvy.

Today, people most commonly use Vitamin C for preventing and treating the common cold.
Vitamin C's also used for autism, breast cancer, heart disease and many other conditions, but there is no good scientific evidence to support many of these uses.

Vitamin C is naturally found in citrus fruits, berries, and green vegetables and is widely used across industries for its antioxidant properties, which help neutralize free radicals, protect cells, and support immune health.
In skincare, Vitamin C is prized for its ability to brighten skin, reduce hyperpigmentation, and promote collagen production.
In the food industry, Vitamin C acts as a preservative, preventing oxidation and extending shelf life.

WHAT IS VITAMIN C USED FOR?
Dietary supplement
Vitamin C, also known as L-Vitamin C, is a water-soluble vitamin.
Unlike most mammals and other animals, humans do not have the ability to synthesize Vitamin C and must obtain it from the diet.

Vitamin C is an essential cofactor in numerous enzymatic reactions, e.g., in the biosynthesis of collagen, carnitine, and neuropeptides, and in the regulation of gene expression.
Vitamin C is also a potent antioxidant. 

Prospective cohort studies indicate that higher Vitamin C status, assessed by measuring circulating Vitamin C, is associated with lower risks of hypertension, coronary heart disease, and stroke. 
Some studies suggest that Vitamin C may be a useful adjunct therapy to mitigate myocardial injury and arrhythmias following cardiac procedures in patients with cardiovascular disease.

There are insufficient data to suggest a link between Vitamin C status and the risk of developing a given type of cancer.
Most observational studies examining Vitamin C intake in relation to cancer incidence have either found no association or a modest, protective association.

Randomized controlled trials have reported no effect of Vitamin C supplementation on cancer risk.
Current evidence on the efficacy of intravenous Vitamin C in cancer patients is mainly limited to observational studies, uncontrolled interventions, and case reports.

There is a need for large, longer-duration phase II clinical trials that test the efficacy of intravenous Vitamin C in cancer progression and overall survival, especially following the recent report of a significant benefit in pancreatic cancer. 
Overall, regular use of Vitamin C supplements does not decrease the risk of coming down with the common cold but does decrease symptom severity and shorten the duration of the illness.

Taking supplements once cold symptoms have already begun has limited benefits. 
Vitamin C supplements are available in many forms.
Several small studies indicate that liposomal-encapsulated Vitamin C might have superior plasma bioavailability compared to other formulations.

There is no scientific evidence that large amounts of Vitamin C (up to 10 grams [g]/day in adults) exert any adverse or toxic effects.
An upper intake level of 2 g/day was set to avoid diarrhea and gastrointestinal disturbances with high supplemental intakes. 

Supplemental Vitamin C increases urinary oxalate concentrations, but whether an increase in urinary oxalate elevates the risk for kidney stones is not yet known.
Those predisposed to kidney stone formation may consider avoiding high-dose (≥1 g/day) Vitamin C supplementation.

BENEFITS OF VITAMIN C:
Vitamin C is a nutrient that cannot be synthesized in the human body, but is required for many biochemical processes.
A healthy and balanced diet is one of the sine qua non for preventing diseases and staying fit.
The most important source of Vitamin C is fruits and vegetables.

However, Vitamin C, which has a very sensitive structure, can be lost up to one hundred percent due to heat (cooking), contact with metal knives or choppers, exposure to light or oxygen.

For this reason, although it can be included in many foods, the main source of Vitamin C in terms of usability is fresh fruits and vegetables.
Vitamin C is a very important nutrient with countless benefits.

Vitamin C is a type of vitamin that the human body needs to form the collagen protein found in blood vessels, cartilage, muscles, and bones.
Vitamin C is of great importance for the healing process after various injuries.

Vitamin C is one of the few antioxidants that can protect the body against damage from harmful molecules called free radicals, as well as pollutants such as toxic chemicals and cigarette smoke.
Vitamin C reduces the risk of chronic diseases.

Vitamin C balances blood lipids.
Vitamin C prevents gout attacks.
Vitamin C increases iron absorption.

Vitamin C strengthens cognitive functions.
Vitamin C strengthens the immune system.

In case of deficiency and increased need, supplements can be given in the form of oral pills, water-soluble tablets, or Vitamin C serum.
Apart from these, the use of Vitamin C supplements is not recommended without consulting a physician.
While Vitamin C at physiological levels creates an antioxidant effect in the body, it also has an oxidant effect in case of high doses, and for this reason, it can be used in the destruction of cancer cells and in the fight against infections.

HEALTH EFFECTS OF VITAMIN C:
Vitamin C has a definitive role in treating scurvy, which is a disease caused by Vitamin C deficiency.
Beyond that, a role for Vitamin C as prevention or treatment for various diseases is disputed, with reviews often reporting conflicting results.
No effect of Vitamin C supplementation reported for overall mortality.

It is on the World Health Organization's List of Essential Medicines and on the World Health Organization's Model Formulary.
In 2023, it was the 226th most commonly prescribed medication in the United States, with more than 1 million prescriptions.

***Scurvy
Scurvy is a disease resulting from a deficiency of Vitamin C.
Without this vitamin, collagen made by the body is too unstable to perform its function and several other enzymes in the body do not operate correctly.
Early symptoms are malaise and lethargy, progressing to shortness of breath, bone pain and susceptibility to bruising.

As the disease progressed, it is characterized by spots on and bleeding under the skin and bleeding gums.
The skin lesions are most abundant on the thighs and legs.
A person with the ailment looks pale, feels depressed, and is partially immobilized.

In advanced scurvy there is fever, old wounds may become open and suppurating, loss of teeth, convulsions and, eventually, death.
Until quite late in the disease the damage is reversible, as healthy collagen replaces the defective collagen with Vitamin C repletion.

Notable human dietary studies of experimentally induced scurvy were conducted on conscientious objectors during World War II in Britain and on Iowa state prisoners in the late 1960s to the 1980s.

Men in the prison study developed the first signs of scurvy about four weeks after starting the Vitamin C-free diet, whereas in the earlier British study, six to eight months were required, possibly due to the pre-loading of this group with a 70 mg/day supplement for six weeks before the scorbutic diet was fed.

Men in both studies had blood levels of Vitamin C too low to be accurately measured by the time they developed signs of scurvy.
These studies both reported that all obvious symptoms of scurvy could be completely reversed by supplementation of only 10 mg a day.
Treatment of scurvy can be with Vitamin C-containing foods or dietary supplements or injection.

***Sepsis
People in sepsis may have micronutrient deficiencies, including low levels of Vitamin C.
An intravenous intake of doses much higher than the RDA, such as 3 g/d or more, appears to be needed to maintain normal plasma concentrations in people with sepsis, as the body's demand for Vitamin C may increase significantly due to the heightened inflammatory response and oxidative stress.
Sepsis mortality may be reduced with administration of intravenous Vitamin C.

***Common cold
Research on Vitamin C in the common cold has been divided into effects on prevention, duration, and severity.
Oral intakes of more than 200 mg/day taken on a regular basis was not effective in prevention of the common cold.
Restricting analysis to trials that used at least 1000 mg/day also saw no prevention benefit.

However, taking a Vitamin C supplement on a regular basis did reduce the average duration of the illness by 8% in adults and 14% in children, and also reduced the severity of colds.

Vitamin C taken on a regular basis reduced the duration of severe symptoms but had no effect on the duration of mild symptoms.
Therapeutic use, meaning that the vitamin was not started unless people started to feel the beginnings of a cold, had no effect on the duration or severity of the illness.

Vitamin C distributes readily in high concentrations into immune cells, promotes natural killer cell activities, promotes lymphocyte proliferation, and is depleted quickly during infections, effects suggesting a prominent role in immune system function.
The European Food Safety Authority concluded there is a cause and effect relationship between the dietary intake of Vitamin C and functioning of a normal immune system in adults and in children under three years of age.

***COVID-19
From March through July 2020, Vitamin C was the subject of more US FDA warning letters than any other ingredient for claims for prevention and/or treatment of COVID-19.
In April 2021, the US National Institutes of Health (NIH) COVID-19 Treatment Guidelines stated that "there are insufficient data to recommend either for or against the use of Vitamin C for the prevention or treatment of COVID-19."

In an update posted December 2022, the NIH position was unchanged:
There is insufficient evidence for the COVID-19 Treatment Guidelines Panel (the Panel) to recommend either for or against the use of Vitamin C for the treatment of COVID-19 in nonhospitalized patients.

There is insufficient evidence for the Panel to recommend either for or against the use of Vitamin C for the treatment of COVID-19 in hospitalized patients.
For people hospitalized with severe COVID-19 there are reports of a significant reduction in the risk of all-cause, in-hospital mortality with the administration of Vitamin C relative to no Vitamin C.

There were no significant differences in ventilation incidence, hospitalization duration or length of intensive care unit stay between the two groups.
The majority of the trials incorporated into these meta-analyses used intravenous administration of the vitamin.

Acute kidney injury was lower in people treated with Vitamin C treatment.
There were no differences in the frequency of other adverse events due to the vitamin.
The conclusion was that further large-scale studies are needed to affirm its mortality benefits before issuing updated guidelines and recommendations.

***Cancer
Higher Vitamin C intake appears to reduce the risk for lung cancer.
There is no evidence that Vitamin C supplementation reduces the risk of prostate cancer,
colorectal cancer or breast cancer.

***Cardiovascular disease
There is no evidence that Vitamin C supplementation decreases the risk of cardiovascular disease,
although there may be an association between higher circulating Vitamin C levels or dietary Vitamin C and a lower risk of stroke.
There is a positive effect of Vitamin C on endothelial dysfunction when taken at doses greater than 500 mg per day.
(The endothelium is a layer of cells that line the interior surface of blood vessels.)

***Blood pressure
Serum Vitamin C was reported to be 15.13 μmol/L lower in people with hypertension compared to normotensives.
The vitamin was inversely associated with both systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Oral supplementation of the vitamin resulted in a very modest but statistically significant decrease in SBP in people with hypertension.
The proposed explanation is that Vitamin C increases intracellular concentrations of tetrahydrobiopterin, an endothelial nitric oxide synthase cofactor that promotes the production of nitric oxide, which is a potent vasodilator.

Vitamin C supplementation might also reverse the nitric oxide synthase inhibitor NG-monomethyl-L-arginine 1, and there is also evidence cited that Vitamin C directly enhances the biological activity of nitric oxide.

***Type 2 diabetes
There are contradictory reviews.
From one, Vitamin C supplementation cannot be recommended for management of type 2 diabetes.
However, another reported that supplementation with high doses of Vitamin C can decrease blood glucose, insulin and hemoglobin A1c.

***Iron deficiency
One of the causes of iron-deficiency anemia is reduced absorption of iron.
Iron absorption can be enhanced through ingestion of Vitamin C alongside iron-containing food or supplements.
Vitamin C helps to keep iron in the reduced ferrous state, which is more soluble and more easily absorbed.

It also chelates iron into a soluble complex.
It specifically helps the absorption of non-heme iron, which is found in non-meat sources and absorbed via DMT1.

***Alzheimer's disease
Lower plasma Vitamin C concentrations were reported in people with Alzheimer's disease.
Reviews do not present reporting on supplement intervention clinical trials.

***Eye health
Higher dietary intake of Vitamin C was associated with lower risk of age-related cataracts.
Vitamin C supplementation did not prevent age-related macular degeneration.

***Periodontal disease
Low intake and low serum concentration were associated with greater progression of periodontal disease.

HOW TO USE VITAMIN C IN YOUR ROUTINE:
Vitamin C in skincare is an effective ingredient that complements other high-performance ingredients to help rejuvenate and improve the appearance of skin, which is easily damaged by environmental aggressors.
Topical Vitamin C can be used with oily, normal, dry, and sensitive skin.

A few drops of Vitamin C can be applied in the morning daily for optimal results.
In the morning, use a gentle cleanser, followed by an Vitamin C serum to brighten and protect against free radicals.
Apply a hydrating moisturizer and complete your morning routine with a broad-spectrum sunscreen for maximum benefits.

WHAT DOES VITAMIN C DO IN THE BODY?
Vitamin C is an essential micronutrient, important to many functions in the body.
Vitamin C plays a key role in creating collagen, a protein essential for maintaining healthy skin, tendons, ligaments, and blood vessels, as well as for repairing wounds and forming scar tissue.

Vitamin C also helps maintain strong bones, cartilage, and teeth.
In addition, Vitamin C boosts the body's ability to absorb iron from plant-based foods.
Vitamin C plays a key role in supporting the immune system.

A powerful antioxidant, Vitamin C neutralizes free radicals — unstable molecules that can damage cells and contribute to aging and diseases like cancer and heart disease.
The micronutrient is also involved in producing neurotransmitters that help nerve cells communicate.

HOW MUCH VITAMIN C DO YOU NEED?
The human body cannot make Vitamin C, so it must be obtained through a person's diet or from supplements.
The amount of Vitamin C you need each day depends on your age, sex, and life stage.
You may need more or less Vitamin C depending on specific health conditions or lifestyle factors.

FOOD FORTIFICATION OF VITAMIN C:
Countries fortify foods with nutrients to address known deficiencies.
While many countries mandate or have voluntary programs to fortify wheat flour, maize (corn) flour or rice with vitamins, none include Vitamin C in those programs.

As described in Vitamin C Fortification of Food Aid Commodities (1997), the United States provides rations to international food relief programs, later under the auspices of the Food for Peace Act and the Bureau for Humanitarian Assistance.

Vitamin C is added to corn-soy blend and wheat-soy blend products at 40 mg/100 grams.
(along with minerals and other vitamins).
Supplemental rations of these highly fortified, blended foods are provided to refugees and displaced persons in camps and to beneficiaries of development feeding programs that are targeted largely toward mothers and children.

The report adds: "The stability of Vitamin C is of concern because this is one of the most labile vitamins in foods.
Its main loss during processing and storage is from oxidation, which is accelerated by light, oxygen, heat, increased pH, high moisture content (water activity), and the presence of copper or ferrous salts.

To reduce oxidation, the Vitamin C used in commodity fortification is coated with ethyl cellulose (2.5 percent).
Oxidative losses also occur during food processing and preparation, and additional Vitamin C may be lost if it dissolves into cooking liquid and is then discarded.

FOOD PRESERVATION ADDITIVE OF VITAMIN C:
Vitamin C and some of its salts and esters are common additives added to foods such as canned fruits, mostly to slow oxidation and enzymatic browning.
Vitamin C may be used as a flour treatment agent used in breadmaking.
As food additives, they are assigned E numbers, with safety assessment and approval the responsibility of the European Food Safety Authority.

THE ROLE OF VITAMIN C IN THE BODY:
Vitamin C, also known as Vitamin C, is essential for the growth, development, and repair of all body tissues.
Vitamin C is involved in numerous bodily functions, including collagen formation, iron absorption, immune system functioning, wound healing, and the maintenance of cartilage, bones, and teeth.

Vitamin C is one of many antioxidants that help protect the body from damage caused by free radicals, as well as harmful chemicals and pollutants such as cigarette smoke.

Free radicals can accumulate and contribute to the development of health conditions like cancer, heart disease, and arthritis
Vitamin C is not stored in the body (excess amounts are excreted), therefore, overdosing on Vitamin C is generally not a concern.
However, Vitamin C is important not to exceed the safe upper limit of 2,000 milligrams per day to avoid stomach discomfort and diarrhea.

Water-soluble vitamins, including Vitamin C, must be consumed regularly through the diet to meet the body’s needs.
Therefore, it is advisable to eat fruits and vegetables rich in Vitamin C or cook Vitamin C-rich foods with minimal water to prevent the loss of water-soluble vitamins during cooking.

Vitamin C is easily absorbed from both food and supplements.
Additionally, Vitamin C enhances iron absorption when both are consumed together.

TOLERABLE UPPER INTAKE LEVEL OF VITAMIN C:
In 2000, the Institute of Medicine of the US National Academy of Sciences set a tolerable upper intake level (UL) for adults of 2,000 mg/day.
The amount was chosen because it had reported diarrhea and other gastrointestinal disturbances at intakes of greater than 3,000 mg/day.
This was the Lowest-Observed-Adverse-Effect Level (LOAEL), meaning that other adverse effects were observed at even higher intakes.

ULs are progressively lower for younger and younger children.: 155–165 
In 2006, the European Food Safety Authority (EFSA) also pointed out the disturbances at that dose level, but reached the conclusion that there was not sufficient evidence to set a UL for Vitamin C, as did the Japan National Institute of Health and Nutrition in 2010.

FOOD LABELING OF VITAMIN C:
For US food and dietary supplement labeling purposes, the amount in a serving is expressed as a percent of Daily Value (%DV).
For Vitamin C labeling purposes, 100% of the Daily Value was 60 mg, but as of May 27, 2016, it was revised to 90 mg to bring it into agreement with the RDA.

A table of the old and new adult daily values is provided at Reference Daily Intake.
European Union regulations require that labels declare energy, protein, fat, saturated fat, carbohydrates, sugars, and salt.

Voluntary nutrients may be shown if present in significant amounts.
Instead of Daily Values, amounts are shown as percent of Reference Intakes (RIs).
For Vitamin C, 100% RI was set at 80 mg in 2011.

SOURCES OF VITAMIN C:
Although also present in other plant-derived foods, the richest natural sources of Vitamin C are fruits and vegetables.
Vitamin C is the most widely taken dietary supplement.

*Plant sources
For Vitamin C content in ten common staple foods such as corn, rice, and wheat, see Staple food § Nutrition.
The following table is approximate and shows the relative abundance in different raw plant sources

*Animal sources
Animal-sourced foods do not generally provide much Vitamin C, and what there is, is largely destroyed by heat during cooking.
For example, raw chicken liver contains 17.9 mg/100 g, but fried, the content is reduced to 2.7 mg/100 g.
Vitamin C is present in human breast milk at 5.0 mg/100 g.
Cow's milk contains 1.0 mg/100 g, but the heat of pasteurization destroys it.

FOOD PREPARATION OF VITAMIN C:
Vitamin C chemically decomposes under certain conditions, many of which may occur during the cooking of food.
Vitamin C concentrations in various food substances decrease with time in proportion to the temperature at which they are stored.
Cooking can reduce the Vitamin C content of vegetables by around 60%, possibly due to increased enzymatic destruction.
Longer cooking times may add to this effect.
Another cause of Vitamin C loss from food is leaching, which transfers Vitamin C to the cooking water, which is decanted and not consumed.

SUPPLEMENTS, VITAMIN C:
Vitamin C dietary supplements are available as tablets, capsules, drink mix packets, in multi-vitamin/mineral formulations, in antioxidant formulations, and as crystalline powder.
Vitamin C is also added to some fruit juices and juice drinks.

Tablet and capsule content ranges from 25 mg to 1500 mg per serving.
The most commonly used supplement compounds are Vitamin C, sodium ascorbate and calcium ascorbate.
Vitamin C molecules can also be bound to the fatty acid palmitate, creating ascorbyl palmitate, or else incorporated into liposomes.

20 FOODS THAT ARE HIGH IN VITAMIN C:
Vitamin C is a water-soluble vitamin that’s found in many foods, particularly fruits and vegetables.
Vitamin C functions as an antioxidant in your body and may help support:

*immune function
*neurotransmitter production
*collagen synthesis
*cardiovascular health
*wound healing

Additionally, Vitamin C is vital for connective tissue, bone, and tooth health.
The current Daily Value (DV) for Vitamin C is 90 milligrams (mg) for men and 75 mg for women.

1. Kakadu plums
The Kakadu plum (Terminalia ferdinandiana) is an Australian native superfood containing 100 times more Vitamin C than oranges.
It has the highest known concentration of Vitamin C of any food, containing up to 2,907 mg per 100 grams (g).
Just one plum (about 15 g) packs around 350 to 480 mg of Vitamin C.
It’s also rich in potassium, vitamin E, and the antioxidant lutein, which may benefit eye health.

2. Acerola cherries
Just 1/2 cup (49 g) of red acerola cherries (Malpighia emarginata) delivers 1650 mg of Vitamin C.
Acerola cherries’ high Vitamin C content provides antioxidant and anti-inflammatory properties.
Cherries are also a rich source of polyphenols, a type of micronutrient found in plants.

Polyphenols can:
*protect your body from oxidative stress
*reduce inflammation
*promote cardiovascular health

3. Rose hips
The rose hip (Rosa canina L.) is a small, sweet, tangy fruit from the rose plant.
And it’s loaded with Vitamin C.
Just 100 g of rose hips provides 426 mg of Vitamin C, or 473% of the DV.

4. Chili peppers
One green chili pepper (Capsicum annuum) contains 109 mg of Vitamin C, or 121% of the DV.
In comparison, one red chili pepper delivers 65 mg, or 72% of the DV.
There’s also some older 2017 evidence that consumption of hot red chili peppers may decrease mortality.
However, more research is needed to fully understand the health benefits of chili peppers.

5. Guavas
A single guava (Psidium guajava) contains 125 mg of Vitamin C, or 138% of the DV.
Guava is particularly rich in the antioxidant lycopene.
A small 2022 study suggests that lycopene may have some anticancer benefits and that guava contains fiber which may help with constipation.

6. Sweet yellow peppers
The Vitamin C content of sweet or bell peppers (Capsicum annuum) increases as they mature.
One large yellow pepper provides 342 mg of Vitamin C, or 380% of the DV, which is more than twice the amount found in a green pepper.

7. Black currants
A half-cup (56 g) of black currants (Ribes nigrum) contains 102 mg of Vitamin C, or 113% of the DV.
Black currants get their rich, dark color from anthocyanins, a type of flavonoids, which have antioxidant effects.
Studies have shown that diets high in antioxidants such as Vitamin C and anthocyanins may reduce oxidative damage associated with chronic diseases such as heart disease, cancer, and neurodegenerative diseases.

8. Cantaloupe
This sweet fruit is packed with not only vitamin A but also Vitamin C.
One cup of sliced cantaloupe (Cucumis melo var. cantalupensis) contains 17 mg of Vitamin C, which is 19% of the amount recommended for adults daily.

9. Parsley
Two tablespoons (8 g) of fresh parsley (Petroselinum crispum) contain 10 mg of Vitamin C, providing 11% of the recommended DV.
Parsley is also a good source of vitamin K and antioxidants.

10. Mustard spinach
One cup of raw chopped mustard spinach (Brassica rapa var. perviridis) provides 195 mg of Vitamin C, or 217% of the DV.
Though heat from cooking reduces the Vitamin C content of foods, 1 cup of cooked mustard greens still provides 117 mg of Vitamin C, or 130% of the DV.

Mustard spinach and other dark, leafy cruciferous vegetables contain other nutrients as well, including:
*vitamin A
*potassium
*calcium
*manganese
*fiber
*folate

11. Kale
Kale (Brassica oleracea var. sabellica) is a cruciferous vegetable.
A 100-g portion of raw kale provides 93 mg of Vitamin C, or 103% of the DV.
It also supplies large amounts of vitamin K and the carotenoids lutein and zeaxanthin.

One cup (118 g) of cooked kale provides 21 mg of Vitamin C, or 23% of the DV.
While cooking this vegetable reduces its Vitamin C content, a 2020 study found that pressure cooking leafy greens can increase the bioavailability of health-promoting compounds.

12. Kiwis
One medium kiwi (Actinidia deliciosa) packs 56 mg of Vitamin C, or 62% of the DV.
2021 research suggests that kiwis can inhibit blood platelets.
This effect may help reduce the risk of blood clots and stroke.
Kiwi consumption may also benefit your immune system.

13. Broccoli
Broccoli (Brassica oleracea var. italica) is a cruciferous vegetable.
A half-cup of cooked broccoli provides 51 mg of Vitamin C, or 57% of the DV.
A 2022 review suggests that eating plenty of cruciferous vegetables rich in Vitamin C may be associated with a decreased risk of cancer.
However, the authors note that 68% of the evidence they looked at was of low quality, indicating that more research needs to be done on this.

14. Brussels sprouts
A half-cup of cooked Brussels sprouts (Brassica oleracea var. gemmifera) provides 48 mg of Vitamin C, or 41% of the DV.
Like most other cruciferous vegetables, Brussels sprouts are high in many vitamins, including vitamin K and vitamin A.

Vitamins C and K are both important for bone health.
In particular, Vitamin C aids in the formation of collagen, which is the fibrous part of your bones.
A 2020 review suggests Vitamin C could have a role to play in the prevention and treatment of osteoporosis, though more research needs to be done.

15. Lemons
One whole raw lemon (Citrus limon) contains 45 mg of Vitamin C, or 50% of the DV.
The Vitamin C in lemon juice also acts as an antioxidant, which is evident in its ability to prevent other fruits and foods from browning.

16. Lychees
One lychee (Litchi chinensis) provides nearly 7 mg of Vitamin C, or 7.5% of the DV, while a 1-cup serving provides 151%.
Research shows that lychees contain polyphenol compounds, including:

*gallic acid
*rutin
*epicatechin
*chlorogenic acid
*caffeic acid
*kaempferol
*quercetin
*luteolin
*apigenin

17. American persimmons
Persimmons are an orange fruit resembling tomatoes.
There are many varieties of persimmons.

Though the Japanese persimmon (Diospyros kaki) is the most popular, the native American persimmon (Diospyros virginiana) contains almost nine times more Vitamin C.
One American persimmon contains 16.5 mg of Vitamin C, or 18% of the DV.

18. Papayas
One cup (145 g) of papaya (Carica papaya) provides 88 mg of Vitamin C, or 98% of the DV.
According to a 2021 review, papaya extracts may treat symptoms of chronic conditions and cancers via their antioxidant properties.

19. Strawberries
One cup of sliced raw strawberries (166 g) provides 97 mg of Vitamin C, or 108% of the DV.
Strawberries (Fragaria x ananassa) contain a potent mix of:

Vitamin C
*manganese
*flavonoids
*folate
*other beneficial antioxidants
One study suggests that 26 g of freeze-dried strawberries may support brain function, lower systolic blood pressure, and increase antioxidant capacity.

20. Oranges
Like other citrus fruits, oranges are high in Vitamin C.
Widely eaten, oranges make up a significant portion of dietary Vitamin C intake.
One medium orange (Citrus sinensis) provides 83 mg of Vitamin C, which is 92% of the DV.
A medium mandarin orange contains 24 mg, or 27% of the DV.

DIET OF VITAMIN C:
RECOMMENDED CONSUMPTION OF VITAMIN C:
Recommendations for Vitamin C intake by adults have been set by various national agencies:

40 mg/day: India National Institute of Nutrition, Hyderabad
45 mg/day or 300 mg/week: the World Health Organization
80 mg/day: the European Commission Council on nutrition labeling
90 mg/day (males) and 75 mg/day (females): Health Canada 2007
90 mg/day (males) and 75 mg/day (females): United States National Academy of Sciences
100 mg/day: Japan National Institute of Health and Nutrition
110 mg/day (males) and 95 mg/day (females): European Food Safety Authority

In 2000, the chapter on Vitamin C in the North American Dietary Reference Intake was updated to give the Recommended Dietary Allowance (RDA) as 90 milligrams per day for adult men, 75 mg/day for adult women, and setting a tolerable upper intake level (UL) for adults of 2,000 mg/day.
The table here shows RDAs for the United States and Canada for children, and for pregnant and lactating women, as well as the ULs for adults.

For the European Union, the EFSA set higher recommendations for adults, and also for children: 20 mg/day for ages 1–3, 30 mg/day for ages 4–6, 45 mg/day for ages 7–10, 70 mg/day for ages 11–14, 100 mg/day for males ages 15–17, 90 mg/day for females ages 15–17.
For pregnancy 100 mg/day; for lactation 155 mg/day.

Cigarette smokers and people exposed to secondhand smoke have lower serum Vitamin C levels than nonsmokers.
The reasoning is that inhalation of smoke causes oxidative damage, depleting this antioxidant vitamin.

The US Institute of Medicine estimated that smokers need 35 mg more Vitamin C per day than nonsmokers, but did not formally establish a higher RDA for smokers.

The US National Center for Health Statistics conducts biannual National Health and Nutrition Examination Survey (NHANES) to assess the health and nutritional status of adults and children in the United States.

Some results are reported as What We Eat In America.
The 2013–2014 survey reported that for adults ages 20 years and older, men consumed on average 83.3 mg/d and women 75.1 mg/d.

This means that half the women and more than half the men are not consuming the RDA for Vitamin C.
The same survey stated that about 30% of adults reported they consumed a Vitamin C dietary supplement or a multi-vitamin/mineral supplement that included Vitamin C, and that for these people total consumption was between 300 and 400 mg/d.

DEFICIENCY OF VITAMIN C:
Plasma Vitamin C is the most widely applied test for Vitamin C status.
Adequate levels are defined as near 50 μmol/L.

Hypovitaminosis of Vitamin C is defined as less than 23 μmol/L, and deficiency as less than 11.4 μmol/L.
For people 20 years of age or above, data from the US 2017–18 National Health and Nutrition Examination Survey showed mean serum concentrations of 53.4 μmol/L.

The percent of people reported as deficient was 5.9%.
Globally, Vitamin C deficiency is common in low and middle-income countries, and not uncommon in high income countries.
In the latter, prevalence is higher in males than in females.

Plasma levels are considered saturated at about 65 μmol/L, achieved by intakes of 100 to 200 mg/day, which are well above the recommended intakes.
Even higher oral intake does not further raise plasma nor tissue concentrations because absorption efficiency decreases and any excess that is absorbed is excreted in urine

USES & EFFECTIVENESS OF VITAMIN C:
*Effective for
Vitamin C deficiency.
Taking Vitamin C by mouth or injecting it as a shot prevents and treats Vitamin C deficiency, including scurvy.
Also, taking Vitamin C can reverse problems associated with scurvy.
Only a healthcare provider can inject Vitamin C as a shot.

*Possibly Effective for
Low levels of red blood cells in people with a long-term illness (anemia of chronic disease).
Taking Vitamin C supplements by mouth might help manage anemia in people undergoing dialysis.

**Irregular heartbeat (atrial fibrillation).
Taking Vitamin C by mouth or by IV before and after heart surgery helps prevent irregular heartbeat after heart surgery.
IV products can only be given by a healthcare provider.

**Emptying the colon before a colonoscopy.
A specific fluid containing Vitamin C (MoviPrep, Salix Pharmaceuticals, Inc.) has been approved by the FDA for bowel preparation before a colonoscopy.
Some bowel preparations involve drinking 4 liters of medicated fluid.
If Vitamin C is included in the fluid, only 2 liters are needed.

**Cataracts.
Eating more Vitamin C or taking Vitamin C supplements by mouth might prevent cataracts.
But it's not clear if taking Vitamin C supplements by mouth helps people who already have cataracts.

**Common cold.
Taking 1-3 grams of Vitamin C by mouth might shorten the course of a cold by 1 to 1.5 days.
But taking Vitamin C does not appear to prevent colds.
Limb pain that usually occurs after an injury (complex regional pain syndrome).
Taking Vitamin C by mouth after surgery or injury seems to prevent complex regional pain syndrome from developing.

**Recovery from laser skin therapy.
Applying a skin cream containing Vitamin C might decrease skin redness after laser skin therapy for scar and wrinkle removal.

**Airway infections caused by exercise.
Taking Vitamin C by mouth before heavy physical exercise, such as a marathon or army training, might prevent upper airway infections that can occur after heavy exercise.

**High cholesterol.
Taking Vitamin C by mouth might reduce low-density lipoprotein (LDL or "bad") cholesterol in people with high cholesterol.

**High blood pressure.
Taking Vitamin C by mouth might help lower systolic blood pressure (the top number in a blood pressure reading) by a small amount.
But it does not seem to lower diastolic pressure (the bottom number).

**Lead poisoning.
Consuming Vitamin C in the diet seems to lower blood levels of lead.
Reduced benefit of nitrate therapy that happens when nitrates are used all day (nitrate tolerance).
Taking Vitamin C by mouth seems to help drugs for chest pain, such as nitroglycerin, to work longer.

**Pain after surgery.
Taking Vitamin C by mouth or by IV might reduce pain during the first 24 hours after surgery.
But it's unclear if taking Vitamin C by mouth can reduce pain during the first 6 weeks after surgery.
IV products can only be given by a healthcare provider.

**Wrinkled skin.
Applying skin creams containing Vitamin C seems to improve the appearance of wrinkled skin.
Applying a Vitamin C patch also seems to help reduce wrinkles.

PHARMACOLOGY OF VITAMIN C:
PHARMACODYNAMICS OF VITAMIN C:
Pharmacodynamics includes enzymes for which Vitamin C is a cofactor, with function potentially compromised in a deficiency state, and any enzyme cofactor or other physiological function affected by administration of Vitamin C, orally or injected, in excess of normal requirements.
At normal physiological concentrations, Vitamin C serves as an enzyme substrate or cofactor and an electron donor antioxidant.

The enzymatic functions include the synthesis of collagen, carnitine, and neurotransmitters; the synthesis and catabolism of tyrosine; and the metabolism of microsomes.
In nonenzymatic functions, Vitamin C acts as a reducing agent, donating electrons to oxidized molecules and preventing oxidation in order to keep iron and copper atoms in their reduced states.

At non-physiological concentrations achieved by intravenous dosing, Vitamin C may function as a pro-oxidant, with therapeutic toxicity against cancer cells.
Vitamin C functions as a cofactor for the following enzymes:

Three groups of enzymes (prolyl-3-hydroxylases, prolyl-4-hydroxylases, and lysyl hydroxylases) that are required for the hydroxylation of proline and lysine in the synthesis of collagen.
These reactions add hydroxyl groups to the amino acids proline or lysine in the collagen molecule via prolyl hydroxylase and lysyl hydroxylase, both requiring Vitamin C as a cofactor.

The role of Vitamin C as a cofactor is to oxidize prolyl hydroxylase and lysyl hydroxylase from Fe2+ to Fe3+ and to reduce it from Fe3+ to Fe2+.
Hydroxylation allows the collagen molecule to assume its triple helix structure, and thus Vitamin C is essential to the development and maintenance of scar tissue, blood vessels, and cartilage.

Two enzymes (ε-N-trimethyl-L-lysine hydroxylase and γ-butyrobetaine hydroxylase) are necessary for synthesis of carnitine.
Carnitine is essential for the transport of fatty acids into mitochondria for ATP generation.
Hypoxia-inducible factor-proline dioxygenase enzymes (isoforms: EGLN1, EGLN2, and EGLN3) allows cells to respond physiologically to low concentrations of oxygen.

Dopamine beta-hydroxylase participates in the biosynthesis of norepinephrine from dopamine.
Peptidylglycine alpha-amidating monooxygenase amidates peptide hormones by removing the glyoxylate residue from their c-terminal glycine residues.
This increases peptide hormone stability and activity.

As an antioxidant, ascorbate scavenges reactive oxygen and nitrogen compounds, thus neutralizing the potential tissue damage of these free radical compounds.
Dehydroascorbate, the oxidized form, is then recycled back to ascorbate by endogenous antioxidants such as glutathione.

In the eye, ascorbate is thought to protect against photolytically generated free-radical damage; higher plasma ascorbate is associated with lower risk of cataracts.

Ascorbate may also provide antioxidant protection indirectly by regenerating other biological antioxidants such as α-tocopherol back to an active state.
In addition, ascorbate also functions as a non-enzymatic reducing agent for mixed-function oxidases in the microsomal drug-metabolizing system that inactivates a wide variety of substrates such as drugs and environmental carcinogens.

PHARMACOKINETICS OF VITAMIN C:
Vitamin C is absorbed in the body by both active transport and passive diffusion.
Approximately 70%–90% of Vitamin C is active-transport absorbed when intakes of 30–180 mg/day from a combination of food sources and moderate-dose dietary supplements such as a multi-vitamin/mineral product are consumed.

However, when large amounts are consumed, such as a Vitamin C dietary supplement, the active transport system becomes saturated, and while the total amount being absorbed continues to increase with dose, absorption efficiency falls to less than 50%.
Active transport is managed by Sodium-Ascorbate Co-Transporter proteins (SVCTs) and Hexose Transporter proteins (GLUTs).
SVCT1 and SVCT2 import ascorbate across plasma membranes.

The Hexose Transporter proteins GLUT1, GLUT3 and GLUT4 transfer only the oxidized dehydroVitamin C (DHA) form of Vitamin C.
The amount of DHA found in plasma and tissues under normal conditions is low, as cells rapidly reduce DHA to ascorbate.
SVCTs are the predominant system for Vitamin C transport within the body.

In both Vitamin C synthesizers (example: rat) and non-synthesizers (example: human) cells maintain Vitamin C concentrations much higher than the approximately 50 micromoles/liter (μmol/L) found in plasma.
For example, the Vitamin C content of pituitary and adrenal glands can exceed 2,000 μmol/L, and muscle is at 200–300 μmol/L.

The known coenzymatic functions of Vitamin C do not require such high concentrations, so there may be other, as yet unknown functions.
A consequence of all this high concentration organ content is that plasma Vitamin C is not a good indicator of whole-body status, and people may vary in the amount of time needed to show symptoms of deficiency when consuming a diet very low in Vitamin C.

Excretion (via urine) is as Vitamin C and metabolites.
The fraction that is excreted as unmetabolized Vitamin C increases as intake increases.
In addition, Vitamin C converts (reversibly) to DHA and from that compound non-reversibly to 2,3-diketogulonate and then oxalate.

These three metabolites are also excreted via urine.
During times of low dietary intake, Vitamin C is reabsorbed by the kidneys rather than excreted.
This salvage process delays onset of deficiency.
Humans are better than guinea pigs at converting DHA back to ascorbate, and thus take much longer to become Vitamin C deficient.

FUNCTION OF VITAMIN C:
Vitamin C is a potent reducing agent, meaning that it readily donates electrons to recipient molecules.
Related to this oxidation-reduction (redox) potential, two major functions of Vitamin C are as an antioxidant and as an enzyme cofactor.
Vitamin C is the primary water-soluble, non-enzymatic antioxidant in plasma and tissues.

Even in small amounts, Vitamin C can protect indispensable molecules in the body, such as proteins, lipids (fats), carbohydrates, and nucleic acids (DNA and RNA), from damage by free radicals and reactive oxygen species (ROS) that are generated during normal metabolism, by active immune cells, and through exposure to toxins and pollutants (e.g., certain chemotherapy drugs and cigarette smoke).

Vitamin C also participates in redox recycling of other important antioxidants; for example, Vitamin C is known to regenerate vitamin E from its oxidized form (see the article on Vitamin E).

The role of Vitamin C as a cofactor is also related to its redox potential.
By maintaining enzyme-bound metals in their reduced forms, Vitamin C assists mixed-function oxidases in the synthesis of several critical biomolecules.
These enzymes are either monooxygenases or dioxygenases.

Symptoms of Vitamin C deficiency, such as poor wound healing and lethargy, likely result from the impairment of these Vitamin C-dependent enzymatic reactions leading to the insufficient synthesis of collagen, carnitine, and catecholamines.
Moreover, several dioxygenases involved in the regulation of gene expression and the maintenance of genome integrity require Vitamin C as a cofactor.

Indeed, research has uncovered the crucial role played by enzymes, such as the TET dioxygenases and Jumonji domain-containing histone demethylases, in the fate of cells and tissues.
These enzymes contribute to the epigenetic regulation of gene expression by catalyzing reactions involved in the demethylation of DNA and histones.

HOW VITAMIN C WORKS:
Vitamin C is a supplement that provides your body with this important vitamin.
Your body needs Vitamin C for several processes.
These roles include keeping your cells healthy, building collagen for joint and skin health, and helping you absorb more iron from food.

FUNCTION OF VITAMIN C:
Vitamin C is needed for the growth and repair of tissues in all parts of your body.
It is used to: Form an important protein called collagen, used to make skin, tendons, ligaments, and blood vessels Heal wounds and form scar tissue Repair and maintain cartilage, bones, and teeth Aid in the absorption of iron.

Vitamin C is one of many antioxidants.
Antioxidants are nutrients that block some of the damage caused by free radicals.

Free radicals are made when your body breaks down food or when you are exposed to tobacco smoke or pollution.
The buildup of free radicals over time is largely responsible for the aging process.

Free radicals may play a role in cancer, heart disease, and conditions like arthritis.
The body is not able to make Vitamin C on its own.

It does not store Vitamin C.
It is therefore important to include plenty of Vitamin C-containing foods in your daily diet.

For many years, Vitamin C has been a popular household remedy for the common cold.
Research shows that for most people, Vitamin C supplements or Vitamin C-rich foods do not reduce the risk of getting the common cold.

However, people who take Vitamin C supplements regularly might have slightly shorter colds or somewhat milder symptoms.
Taking a Vitamin C supplement after a cold starts does not appear to be helpful.

FOOD SOURCES OF VITAMIN C:
All fruits and vegetables contain some amount of Vitamin C.
Fruits with the highest content of Vitamin C include: 
Cantaloupe Citrus fruits and juices, such as orange and grapefruit Kiwi fruit Mango Papaya Pineapple Strawberries, raspberries, blueberries, and cranberries Watermelon.

Vegetables with the highest sources of Vitamin C include: 
Broccoli, Brussels sprouts, and cauliflower Green and red peppers Spinach, cabbage, turnip greens, and other leafy greens Sweet and white potatoes Tomatoes and tomato juice Winter squash.
Some cereals and other foods and beverages are fortified with Vitamin C.
Fortified means a vitamin or mineral has been added to the food.

BENEFITS OF VITAMIN C:
There are also claims of benefits from Vitamin C supplementation in excess of the recommended dietary intake for people who are not considered Vitamin C deficient.
Vitamin C is generally well tolerated.

Large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin.
The United States National Academy of Medicine recommends Vitamin C against consuming large amounts.
Most animals are able to synthesize their own Vitamin C.

However, higher primates (including humans), most bats, guinea pigs, some fish species, and some bird species must acquire Vitamin C from dietary sources because a gene for a synthesis enzyme has mutations that render it dysfunctional.
Vitamin C was discovered in 1912, isolated in 1928, and in 1933, was the first vitamin to be chemically produced.
Partly for Vitamin C's discovery, Albert Szent-Györgyi was awarded the 1937 Nobel Prize in Physiology or Medicine.

WHAT THE RESEARCH SAYS ABOUT VITAMIN C:
Research on the use of Vitamin C for the following conditions shows:

*Cancer.
Eating a diet rich in fruits and vegetables might lower the risk of many types of cancer, such as breast, colon and lung cancers.
But it's not clear whether this effect is related to the Vitamin C content in the food.
Taking Vitamin C supplements doesn't seem to affect cancer risk.

*Cardiovascular disease.
Much research has focused on whether Vitamin C supplements protect against heart disease.
Taking supplements doesn't seem to affect heart disease risk.

*Common cold.
Taking oral Vitamin C supplements won't prevent the common cold.
Studies show that taking Vitamin C supplements has little effect on how long colds last or how bad they are.

*Eye diseases.
Taking oral Vitamin C supplements with other vitamins and minerals seems to keep age-related macular degeneration, also called AMD, from getting worse.
AMD is a leading cause of vision loss among older adults.
Some studies also suggest that people who have higher levels of Vitamin C in their diets have a lower risk of getting cataracts.

THE BENEFITS OF VITAMIN C FOR HEALTH:
Vitamin C can offer health benefits by alleviating symptoms such as:
Stress: 
A recent meta-analysis found that Vitamin C is beneficial for individuals with weakened immune systems due to stress—a very common condition in society.
Because Vitamin C is one of the nutrients most affected by stress and is often deficient in people who consume alcohol, smoke or are obese.

*Cold: 
While Vitamin C may not be a cure for the common cold.
However, some studies suggest it can help prevent more severe complications.
Evidence from several studies indicates that taking Vitamin C during a cold or flu can reduce the risk of developing complications such as pneumonia or lung infections.

*Stroke: 
Although research findings are inconsistent, a study published in the American Journal of Clinical Nutrition found that individuals with the highest blood levels of Vitamin C had a 42% lower risk of stroke compared to those with the lowest levels.

*Skin Aging: 
Vitamin C affects cells both inside and outside the body.
A study published in the American Journal of Clinical Nutrition examined the relationship between nutrient intake and skin aging in 4,025 women aged 40 to 47.

The results showed that higher Vitamin C intake was associated with a lower likelihood of wrinkles, dry skin, and visible signs of skin aging.
In addition, other studies have also shown the benefits of Vitamin C, such as improving age-related macular degeneration, reducing inflammation, and lowering the risk of cancer and cardiovascular diseases.

HOW TO TAKE VITAMIN C:
Vitamin C comes in various forms, such as Vitamin C, mineral ascorbates (sodium ascorbate, calcium ascorbate), or Vitamin C combined with bioflavonoids.
For Vitamin C supplementation, Vitamin C is a good choice.
Because, Vitamin C has high bioavailability, (meaning the body absorbs it easily).

Additionally, since most multivitamins contain Vitamin C, choosing a multivitamin not only increases Vitamin C intake but also provides other essential nutrients.
To ensure the body gets enough Vitamin C from supplements, look for products that provide 45 to 120 mg of Vitamin C, with the dosage depending on age and gender.

WHEN SHOULD VITAMIN C BE TAKEN?
The best time to take Vitamin C is on an empty stomach.
This means taking Vitamin C in the morning, 30 minutes before a meal, or two hours after eating.
Vitamin C is a water-soluble vitamin, making it easy for the body to absorb.
The body only uses the required amount and any excess is excreted through urine.
As a result, Vitamin C is not stored in the body.

RECOMMENDATIONS FOR VITAMIN C INTAKE FROM FOOD:
Recommended dietary intake of Vitamin C from food by age and gender:
Children aged 1 to 3 years: 15 mg
Children aged 4 to 8 years: 25 mg
Pre-teens (9 to 13 years): 45 mg
Teenagers (14 to 18 years): 65-75 mg
Adult women (19 years and older): 75 mg
Adult men (19 years and older): 90 mg
Pregnant women: 85 mg
Breastfeeding mothers: 120 mg

The U.S. Food and Drug Administration (FDA) has issued the Daily Value (DV) recommendations.
The DV is developed for food and supplement labeling as well as to help individuals determine the percentage of a nutrient in a single serving of food relative to daily needs.

On food labels, this value is displayed as %DV.
The DV for Vitamin C recommended for adults and children aged 4 years and older is 60 mg.
However, as of January 2020, this value increased to 90 mg.

FOOD SOURCES RICH IN VITAMIN C:
Fruits and vegetables are the richest sources of Vitamin C.
However, Vitamin C is easily destroyed by factors such as heat and light,...
Therefore, it is important to know how to minimize Vitamin C loss in fruits and vegetables.
Some fruits and vegetables high in Vitamin C include citrus fruits, green peppers, strawberries, tomatoes, broccoli, white potatoes, sweet potatoes, dark green leafy vegetables, cantaloupe, papaya, mango, cauliflower, cabbage, raspberries, and blueberries.

ANIMAL SYNTHESIS, VITAMIN C:
There is some information on serum Vitamin C concentrations maintained in animal species that are able to synthesize Vitamin C.
The biosynthesis of Vitamin C in vertebrates starts with the formation of UDP-glucuronic acid.
UDP-glucuronic acid is formed when UDP-glucose undergoes two oxidations catalyzed by the enzyme UDP-glucose 6-dehydrogenase.
UDP-glucose 6-dehydrogenase uses the co-factor NAD+ as the electron acceptor.

The transferase UDP-glucuronate pyrophosphorylase removes a UMP and glucuronokinase, with the cofactor ADP, removes the final phosphate leading to d-glucuronic acid.
The aldehyde group of this compound is reduced to a primary alcohol using the enzyme glucuronate reductase and the cofactor NADPH, yielding l-gulonic acid.

This is followed by lactone formation—utilizing the hydrolase gluconolactonase—between the carbonyl on C1 and hydroxyl group on C4.
l-Gulonolactone then reacts with oxygen, catalyzed by the enzyme L-gulonolactone oxidase (which is nonfunctional in humans and other Haplorrhini primates; see Unitary pseudogenes) and the cofactor FAD+.

This reaction produces 2-oxogulonolactone (2-keto-gulonolactone), which spontaneously undergoes enolization to form Vitamin C.
Reptiles and older orders of birds make Vitamin C in their kidneys.
Recent orders of birds and most mammals make Vitamin C in their liver.

NON-SYNTHESIZERS, VITAMIN C:
Some mammals have lost the ability to synthesize Vitamin C, including simians and tarsiers, which together make up one of two major primate suborders, Haplorhini.
This group includes humans.
The other more primitive primates (Strepsirrhini) have the ability to make Vitamin C.

Synthesis does not occur in some species in the rodent family Caviidae, which includes guinea pigs and capybaras, but does occur in other rodents, including rats and mice.
Synthesis does not occur in most bat species, but there are at least two species, frugivorous bat Rousettus leschenaultii and insectivorous bat Hipposideros armiger, that retain (or regained) their ability of Vitamin C production.

A number of species of passerine birds also do not synthesize, but not all of them, and those that do not are not clearly related; it has been proposed that the ability was lost separately a number of times in birds.

In particular, the ability to synthesize Vitamin C is presumed to have been lost and then later re-acquired in at least two cases.
The ability to synthesize Vitamin C has also been lost in about 96% of extant fish (the teleosts).

On a milligram consumed per kilogram of body weight basis, simian non-synthesizer species consume the vitamin in amounts 10 to 20 times higher than what is recommended by governments for humans.
This discrepancy constituted some of the basis of the controversy on human recommended dietary allowances being set too low.

However, simian consumption does not indicate simian requirements.
Merck's veterinary manual states that daily intake of Vitamin C at 3–6 mg/kg prevents scurvy in non-human primates.
By way of comparison, across several countries, the recommended dietary intake for adult humans is in the range of 1–2 mg/kg.

CHEMISTRY OF VITAMIN C:
The name "vitamin C" always refers to the l-enantiomer of Vitamin C and its oxidized form, dehydroascorbate (DHA).
Therefore, unless written otherwise, "ascorbate" and "Vitamin C" refer in the nutritional literature to l-ascorbate and l-ascorbic acid respectively.

Vitamin C is a weak sugar acid structurally related to glucose. 
In biological systems, Vitamin C can be found only at low pH, but in solutions above pH 5 it is predominantly found in the ionized form, ascorbate.

Many analytical methods have been developed for Vitamin C detection. 
For example, Vitamin C content of a food sample such as fruit juice can be calculated by measuring the volume of the sample required to decolorize a solution of dichlorophenolindophenol (DCPIP) and then calibrating the results by comparison with a known concentration of vitamin C.

SYNTHESIS OF VITAMIN C:
Most animals and plants are able to synthesize vitamin C through a sequence of enzyme-driven steps, which convert monosaccharides to vitamin C.
Yeasts do not make l-ascorbic acid but rather its stereoisomer, erythorbic acid.
In plants, synthesis is accomplished through the conversion of mannose or galactose to ascorbic acid.

In animals, the starting material is glucose.
In some species that synthesize Vitamin C in the liver (including mammals and perching birds), the glucose is extracted from glycogen; 
Vitamin C synthesis is a glycogenolysis-dependent process.
In humans and in animals that cannot synthesize vitamin C, the enzyme l-gulonolactone oxidase (GULO), which catalyzes the last step in the biosynthesis, is highly mutated and non-functional.

EVOLUTION OF ANIMAL SYNTHESIS OF VITAMIN C:
Vitamin C is a common enzymatic cofactor in mammals used in the synthesis of collagen, as well as a powerful reducing agent capable of rapidly scavenging a number of reactive oxygen species (ROS).
Given that Vitamin C has these important functions, it is surprising that the ability to synthesize this molecule has not always been conserved.

In fact, anthropoid primates, Cavia porcellus (guinea pigs), teleost fishes, most bats, and some passerine birds have all independently lost the ability to internally synthesize vitamin C in either the kidney or the liver.

In all of the cases where genomic analysis was done on an Vitamin C auxotroph, the origin of the change was found to be a result of loss-of-function mutations in the gene that encodes L-gulono-γ-lactone oxidase, the enzyme that catalyzes the last step of the Vitamin C pathway outlined above.

One explanation for the repeated loss of the ability to synthesize vitamin C is that it was the result of genetic drift; assuming that the diet was rich in vitamin C, natural selection would not act to preserve it.

In the case of the simians, it is thought that the loss of the ability to make vitamin C may have occurred much farther back in evolutionary history than the emergence of humans or even apes, since it evidently occurred soon after the appearance of the first primates, yet sometime after the split of early primates into the two major suborders Haplorrhini (which cannot make vitamin C) and its sister suborder of non-tarsier prosimians, the Strepsirrhini ("wet-nosed" primates), which retained the ability to make vitamin C.

According to molecular clock dating, these two suborder primate branches parted ways about 63 to 60 million years ago.
Approximately three to five million years later (58 million years ago), only a short time afterward from an evolutionary perspective, the infraorder Tarsiiformes, whose only remaining family is that of the tarsier (Tarsiidae), branched off from the other haplorrhines.

Since tarsiers also cannot make vitamin C, this implies the mutation had already occurred, and thus must have occurred between these two marker points (63 to 58 million years ago).

It has also been noted that the loss of the ability to synthesize Vitamin C strikingly parallels the inability to break down uric acid, also a characteristic of primates.

Uric acid and Vitamin C are both strong reducing agents.
This has led to the suggestion that, in higher primates, uric acid has taken over some of the functions of Vitamin C.

PLANT SYNTHESIS OF VITAMIN C:
There are many different biosynthesis pathways to Vitamin C in plants.
Most proceed through products of glycolysis and other metabolic pathways.
For example, one pathway utilizes plant cell wall polymers.

The principal plant Vitamin C biosynthesis pathway seems to be via l-galactose.
The enzyme l-galactose dehydrogenase catalyzes the overall oxidation to the lactone and isomerization of the lactone to the C4-hydroxyl group, resulting in l-galactono-1,4-lactone.

l-Galactono-1,4-lactone then reacts with the mitochondrial flavoenzyme l-galactonolactone dehydrogenase to produce Vitamin C.
l-Vitamin C has a negative feedback on l-galactose dehydrogenase in spinach.

Vitamin C efflux by embryos of dicot plants is a well-established mechanism of iron reduction and a step obligatory for iron uptake.
All plants synthesize Vitamin C.

Vitamin C functions as a cofactor for enzymes involved in photosynthesis, synthesis of plant hormones, as an antioxidant and regenerator of other antioxidants.
Plants use multiple pathways to synthesize vitamin C.

The major pathway starts with glucose, fructose or mannose (all simple sugars) and proceeds to l-galactose, l-galactonolactone and Vitamin C.
This biosynthesis is regulated following a diurnal rhythm.

Enzyme expression peaks in the morning to supporting biosynthesis for when mid-day sunlight intensity demands high Vitamin C concentrations.
Minor pathways may be specific to certain parts of plants; these can be either identical to the vertebrate pathway (including the GLO enzyme), or start with inositol and get to Vitamin C via l-galactonic acid to l-galactonolactone.

INDUSTRIAL SYNTHESIS OF VITAMIN C:
Vitamin C can be produced from glucose by two main routes.
The no longer utilized Reichstein process, developed in the 1930s, used a single fermentation followed by a purely chemical route.

The modern two-step fermentation process, originally developed in China in the 1960s, uses additional fermentation to replace part of the later chemical stages.

The Reichstein process and the modern two-step fermentation processes both use glucose as the starting material, convert that to sorbitol, and then to sorbose using fermentation.

The two-step fermentation process then converts sorbose to 2-keto-l-gulonic acid (KGA) through another fermentation step, avoiding an extra intermediate.

Both processes yield approximately 60% Vitamin C from the glucose starting point.
Researchers are exploring means for one-step fermentation.

HISTORY OF VITAMIN C:
Scurvy was known to Hippocrates, described in book two of his Prorrheticorum and in his Liber de internis affectionibus, and cited by James Lind.
Symptoms of scurvy were also described by Pliny the Elder: (i) Pliny. "49". Naturalis historiae. Vol. 3.; and (ii) Strabo, in Geographicorum, book 16, cited in the 1881 International Encyclopedia of Surgery

*Scurvy at sea
In the 1497 expedition of Vasco da Gama, the curative effects of citrus fruit were known.
In the 1500s, Portuguese sailors put in to the island of Saint Helena to avail themselves of planted vegetable gardens and wild-growing fruit trees.

Authorities occasionally recommended plant food to prevent scurvy during long sea voyages.
John Woodall, the first surgeon to the British East India Company, recommended the preventive and curative use of lemon juice in his 1617 book, The Surgeon's Mate.

In 1734, the Dutch writer Johann Bachstrom gave the firm opinion, "scurvy is solely owing to a total abstinence from fresh vegetable food, and greens."
Scurvy had long been a principal killer of sailors during the long sea voyages.

According to Jonathan Lamb, "In 1499, Vasco da Gama lost 116 of his crew of 170; In 1520, Magellan lost 208 out of 230; ... all mainly to scurvy.
The first attempt to give scientific basis for the cause of this disease was by a ship's surgeon in the Royal Navy, James Lind.

While at sea in May 1747, Lind provided some crew members with two oranges and one lemon per day, in addition to normal rations, while others continued on cider, vinegar, sulfuric acid or seawater, along with their normal rations, in one of the world's first controlled experiments.

The results showed that citrus fruits prevented the disease.
Lind published his work in 1753 in his Treatise on the Scurvy.

Fresh fruit was expensive to keep on board, whereas boiling it down to juice allowed easy storage, but destroyed the vitamin (especially if it was boiled in copper kettles).
It was 1796 before the British navy adopted lemon juice as standard issue at sea.

In 1845, ships in the West Indies were provided with lime juice instead, and in 1860 lime juice was used throughout the Royal Navy, giving rise to the American use of the nickname "limey" for the British.

Captain James Cook had previously demonstrated the advantages of carrying "Sour krout" on board by taking his crew on a 1772–75 Pacific Ocean voyage without losing any of his men to scurvy.
For his report on his methods the British Royal Society awarded him the Copley Medal in 1776.

The name antiscorbutic was used in the eighteenth and nineteenth centuries for foods known to prevent scurvy.
These foods included lemons, limes, oranges, sauerkraut, cabbage, malt, and portable soup.

In 1928, the Canadian Arctic anthropologist Vilhjalmur Stefansson showed that the Inuit avoided scurvy on a diet largely of raw meat.
Later studies on traditional food diets of the Yukon First Nations, Dene, Inuit, and Métis of Northern Canada showed that their daily intake of Vitamin C averaged between 52 and 62 mg/day.

Vitamin C was discovered in 1912, isolated in 1928 and synthesized in 1933, making it the first vitamin to be synthesized.
Shortly thereafter Tadeus Reichstein succeeded in synthesizing the vitamin in bulk by what is now called the Reichstein process.

This made possible the inexpensive mass-production of vitamin C.
In 1934, Hoffmann–La Roche bought the Reichstein process patent, trademarked synthetic vitamin C under the brand name Redoxon, and began to market it as a dietary supplement.

In 1912, the Polish biochemist Casimir Funk developed the concept of vitamins.
One of these was thought to be the anti-scorbutic factor.

In 1928, this was referred to as "water-soluble C", although its chemical structure had not been determined.
From 1928 to 1932, Albert Szent-Györgyi and Joseph L. Svirbely's Hungarian team, and Charles Glen King's American team, identified the anti-scorbutic factor.

Szent-Györgyi isolated hexuronic acid from animal adrenal glands, and suspected it to be the antiscorbutic factor.
In late 1931, Szent-Györgyi gave Svirbely the last of his adrenal-derived hexuronic acid with the suggestion that it might be the anti-scorbutic factor.

By the spring of 1932, King's laboratory had proven this, but published the result without giving Szent-Györgyi credit for it.
This led to a bitter dispute over priority.
In 1933, Walter Norman Haworth chemically identified the vitamin as l-hexuronic acid, proving this by synthesis in 1933.

Haworth and Szent-Györgyi proposed that L-hexuronic acid be named a-scorbic acid, and chemically l-Vitamin C, in honor of its activity against scurvy.
The term's etymology is from Latin, "a-" meaning away, or off from, while -scorbic is from Medieval Latin scorbuticus (pertaining to scurvy), cognate with Old Norse skyrbjugr, French scorbut, Dutch scheurbuik and Low German scharbock.

Partly for this discovery, Szent-Györgyi was awarded the 1937 Nobel Prize in Medicine, and Haworth shared that year's Nobel Prize in Chemistry.
In 1957, J. J. Burns showed that some mammals are susceptible to scurvy as their liver does not produce the enzyme l-gulonolactone oxidase, the last of the chain of four enzymes that synthesize vitamin C.

American biochemist Irwin Stone was the first to exploit vitamin C for its food preservative properties.
He later developed the idea that humans possess a mutated form of the l-gulonolactone oxidase coding gene.

Stone introduced Linus Pauling to the theory that humans needed to consume vitamin C in quantities far higher than what was considered a recommended daily intake in order to optimize health.

In 2008, researchers discovered that in humans and other primates the red blood cells have evolved a mechanism to more efficiently utilize the vitamin C present in the body by recycling oxidized l-dehydroascorbic acid (DHA) back into Vitamin C for reuse by the body.
The mechanism was not found to be present in mammals that synthesize their own vitamin C.

HISTORY OF LARGE DOSE THERAPIES OF VITAMIN C:
Vitamin C mega dosage is a term describing the consumption or injection of vitamin C in doses comparable to or higher than the amounts produced by the livers of mammals which are able to synthesize vitamin C.
An argument for this, although not the actual term, was described in 1970 in an article by Linus Pauling.

Briefly, his position was that for optimal health, humans should be consuming at least 2,300 mg/day to compensate for the inability to synthesize vitamin C.
The recommendation also fell into the consumption range for gorillas — a non-synthesizing near-relative to humans.

A second argument for high intake is that serum Vitamin C concentrations increase as intake increases until it plateaus at about 190 to 200 micromoles per liter (μmol/L) once consumption exceeds 1,250 milligrams.

As noted, government recommendations are a range of 40 to 110 mg/day and normal plasma is approximately 50 μmol/L, so "normal" is about 25% of what can be achieved when oral consumption is in the proposed megadose range.

Pauling popularized the concept of high dose vitamin C as prevention and treatment of the common cold in 1970.
A few years later he proposed that vitamin C would prevent cardiovascular disease, and that 10 grams/day, initially administered intravenously and thereafter orally, would cure late-stage cancer.

Mega-dosing with Vitamin C has other champions, among them chemist Irwin Stone and the controversial Matthias Rath and Patrick Holford, who both have been accused of making unsubstantiated treatment claims for treating cancer and HIV infection.

The idea that large amounts of intravenous Vitamin C can be used to treat late-stage cancer or ameliorate the toxicity of chemotherapy is — some forty years after Pauling's seminal paper — still considered unproven and still in need of high quality research.

HOW TO CHOOSE THE RIGHT FORM FOR YOUR FORMULATION:
Formulators must weigh several factors when deciding between Vitamin C, L-ascorbic acid, or derivatives:

*Target Audience:
Is the product for sensitive skin or high-performance results?

*Product Type:
Serums benefit from L-ascorbic acid, while creams may use SAP for stability.

*Storage and Packaging:
L-Ascorbic acid requires protective packaging to maintain efficacy.

*Budget:
Derivatives like SAP are more cost-effective but less potent.

PRACTICAL APPLICATIONS ACROSS INDUSTRIES
The differences between Vitamin C, L-ascorbic acid, and derivatives like SAP have practical implications across industries:

*Skincare:
L-Ascorbic acid is used in high-potency serums (10-20% concentration) for anti-aging and brightening.
SAP is common in gentler formulations like creams or toners.

*Food and Beverage:
Ascorbic acid acts as a preservative and antioxidant, extending shelf life in juices, canned goods, and supplements.

*Pharmaceuticals:
L-Ascorbic acid is used in supplements for its bioavailability, while Vitamin C derivatives may be used in topical treatments.

ASCORBIC ACID VS. L-ASCORBIC ACID: THE KEY DIFFERENCES
Understanding the differences between Vitamin C vs. L-ascorbic acid, as well as derivatives like sodium ascorbyl phosphate (SAP), is vital for developing high-performance and stable formulations across skincare, food, and pharmaceutical industries.

L-ascorbic acid, known for its superior antioxidant properties and collagen-boosting effects, is commonly used in powerful anti-aging skincare products.
However, its instability—especially in the presence of air, light, or heat—means it requires precise formulation and high-quality sourcing to remain effective.

In contrast, derivatives such as SAP offer a more stable, water-soluble, and gentler option, making them ideal for sensitive skin and long-shelf-life products.
These forms still deliver Vitamin C benefits, but with improved formulation flexibility and reduced oxidation risk.
For food and pharma applications, choosing the right form also affects shelf life, taste, and bioavailability.

ASCORBIC ACID VS. L-ASCORBIC ACID: THE KEY DIFFERENCES
While Vitamin C vs. L-ascorbic acid may seem like a minor distinction, the differences are significant for formulators.
Here’s a breakdown:

1. Chemical Structure
Ascorbic Acid: Refers to the general compound, which includes both L-ascorbic acid and its less active isomer, D-ascorbic acid.
D-ascorbic acid has limited biological activity and is rarely used in formulations.
L-Ascorbic Acid: The specific L-isomer of Vitamin C, recognized by the body and skin for its antioxidant and collagen-boosting properties.

2. Bioavailability
Ascorbic Acid: When used generically, it may include less bioavailable forms, reducing its efficacy in skincare or dietary applications.
L-Ascorbic Acid: Offers superior bioavailability, making it more effective for topical applications and nutritional benefits.

3. Stability
Ascorbic Acid: As a broad term, its stability depends on the specific form or derivative used.
Pure Vitamin C (often L-ascorbic acid) is highly unstable.
L-Ascorbic Acid: Highly unstable in aqueous solutions, especially at high pH, requiring careful formulation to maintain efficacy.

4. Efficacy in Skincare
Ascorbic Acid: May include derivatives like sodium ascorbyl phosphate, which are less potent but more stable.
L-Ascorbic Acid: Delivers maximum efficacy for brightening, anti-aging, and antioxidant protection but requires precise formulation to prevent degradation.

5. Applications
Ascorbic Acid: Used broadly in food, cosmetics, and pharmaceuticals, often as a cost-effective antioxidant or preservative.
L-Ascorbic Acid: Preferred in high-performance skincare products where potency is critical, such as serums targeting fine lines or hyperpigmentation.

SODIUM ASCORBYL PHOSPHATE VS. Vitamin C: A COMMON ALTERNATIVE
When discussing sodium ascorbyl phosphate vs. Vitamin C, it’s important to note that sodium ascorbyl phosphate (SAP) is a derivative of Vitamin C.
SAP is more stable than L-ascorbic acid, especially in water-based formulations, and is less likely to degrade when exposed to light or air.

However, its stability comes at the cost of reduced potency.
SAP must be converted into L-ascorbic acid by enzymes in the skin, which makes it less effective for immediate results compared to pure L-ascorbic acid.

For formulators, choosing between sodium ascorbyl phosphate vs. Vitamin C depends on the product’s goals:
SAP: Ideal for products targeting sensitive skin or requiring longer shelf life, such as moisturizers or cleansers.
L-Ascorbic Acid: Best for high-potency serums where rapid, visible results are the priority.

WHY IT MATTERS IN FORMULATION
Choosing between Vitamin C, L-ascorbic acid, or derivatives like sodium ascorbyl phosphate significantly impacts a product’s performance, stability, and cost.
Here’s why these differences matter:

1. Product Efficacy
L-Ascorbic acid’s superior bioavailability makes it the top choice for skincare products aiming to deliver noticeable results, such as reducing dark spots or fine lines.
However, its instability requires additional stabilizers like ferulic acid or Vitamin E, increasing formulation complexity.

2. Stability and Shelf Life
L-Ascorbic acid’s sensitivity to environmental factors can lead to oxidation, causing products to lose efficacy or develop an off-color.
Derivatives like SAP offer better stability, making them suitable for products with longer shelf lives or less controlled storage conditions.

3. Cost Considerations
Pure L-ascorbic acid is often more expensive due to its potency and the need for specialized packaging (e.g., airless pumps or dark glass bottles).
SAP and other derivatives are more cost-effective, appealing to brands balancing quality and budget.

4. Consumer Experience
L-Ascorbic acid can irritate sensitive skin due to its low pH, while derivatives like SAP are gentler, making them better suited for a broader audience.
Formulators must consider the target market when selecting ingredients.

5. Regulatory and Sourcing Needs
High-quality sourcing is critical for ensuring ingredient purity and consistency.

PHYSICAL and CHEMICAL PROPERTIES of VITAMIN C:
Formula: C6H8O6
Molar mass: 176.124 g•mol−1
Density: 1.694 g/cm3
Melting point: 190 to 192 °C (374 to 378 °F)
Boiling point: 552.7 °C (1,026.9 °F)  
CAS Number: 50-81-7
as salt: 134-03-2
E number: E300 (antioxidants, ...)

Product Name: Vitamin C (Vitamin C) E300
Chemical Name: L-Vitamin C, Vitamin C, Ascorvit, Vicomin C
Chemical Formula: H₂C₆H₆O₆
Appearance: White crystalline or powder form, with a slightly acidic odor.
Chemical Name: L-Vitamin C
IUPAC Name: (2R)-2-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxy-2H-furan-5-one
CAS Number: 50-81-7 2 
EC Number: 200-066-2 3 

E Number: E300
Molecular Formula: C₆H₈O₆
Molecular Weight: 176.12 g/mol 
Appearance: White to off-white crystalline powder
Odour: Odourless
Taste: Sour
Solubility: Highly soluble in water (330 g/L at 24°C); slightly soluble in ethanol (20 g/L at 20°C)
pH (50 g/L solution): Approximately 2.2–2.5

Density: ~1.65 g/cm³  
Melting Point: 190–192°C (decomposes) 
Stability: Sensitive to light, heat, and air; degrades upon exposure 
INCI: VITAMIN C
CAS: 50-81-7
Molar mass: 176,12 g/mol
Density: 1,694 g/cm3
Solubility: In water 58 g/100 ml
Chemical Formula: C₆H₈O₆

Molecular Weight: 176.12 g/mol
Physical State: White or slightly yellow crystalline powder
Melting Point: 190-194°C (decomposes)
Solubility: Highly soluble in water
pH: 3.59 (1 mM solution)
Molecular Formula (Vitamin C): C6H8O6
Molecular Weight: 176.174 g/mol
Chemical Name: Vitamin C (Vitamin C)
CAS Number: 50-81-7  

FIRST AID MEASURES of VITAMIN C:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation: 
Fresh air.
*In case of skin contact: 
Take off immediately all contaminated clothing. 
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact: 
Rinse out with plenty of water. 
Call in ophthalmologist. 
Remove contact lenses.
*If swallowed:
After swallowing: 
Immediately make victim drink water (two glasses at most). 
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available

ACCIDENTAL RELEASE MEASURES of VITAMIN C:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains. 
Collect, bind, and pump off spills. 
Observe possible material restrictions. 
Take up dry. 
Dispose of properly. 
Clean up affected area.

FIRE FIGHTING MEASURES of VITAMIN C:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2) 
Foam 
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.

EXPOSURE CONTROLS/PERSONAL PROTECTION of VITAMIN C:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection. 
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A 
-Control of environmental exposure:
Do not let product enter drains.

HANDLING and STORAGE of VITAMIN C:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed. 
Dry.

STABILITY and REACTIVITY of VITAMIN C:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature) .
-Possibility of hazardous reactions:
No data available