Vitamin C

Vitamin C

Clinical data
Other names	Ascorbic acid
Pregnancy category	A
Routes of administration	oral
ATC code	A11G (WHO)
Legal status
Legal status	general public availability
Pharmacokinetic data
Bioavailability	rapid & complete
Protein binding	negligible
Elimination half-life	30 minutes
Excretion	renal
Identifiers
IUPAC name 2-oxo-L-threo-hexono-1,4- lactone-2,3-enediol or (R)-3,4-dihydroxy-5-((S)- 1,2-dihydroxyethyl)furan-2(5H)-one
CAS Number	50-81-7
PubChem CID	644104
E number	E300 (antioxidants, ...)
CompTox Dashboard (EPA)	DTXSID5020106
ECHA InfoCard	100.000.061
Chemical and physical data
Formula	C6H8O6
Molar mass	176.13 g·mol−1
3D model (JSmol)	Interactive image
Melting point	190 to 192 °C (374 to 378 °F) decomposes
SMILES OC1=C(C(O[C@@H]1[C@H](CO)O)=O)O

This article is about the nutrient. For the chemical compound, see ascorbic acid. For other uses, see Vitamin C (disambiguation).

Vitamin C or L-ascorbic acid is an essential nutrient required in small amounts in order to allow a range of essential metabolic reactions in animals and plants. Vitamin C is widely known as the vitamin that prevents scurvy in humans. The joint US-Canadian Dietary Reference Intake recommends 90 milligrams per day and no more than 2 grams per day (2000 milligrams per day), although the amount that humans require for optimum health is a matter of heated debate.

Chemically, ascorbic acid exists in two forms: the active reduced form is ascorbic acid, while the oxidized form is dehydroascorbic acid. Dehydroscorbic acid present in the diet can be reduced to the active form in the body by enzymes and glutathione. Ascorbic acid is an antioxidant and protects the body against oxidative stress as well as being needed as a cofactor in some enzyme reactions. The article on ascorbic acid contains further information on its chemical properties. This article describes its biological functions, discovery and the continuing scientific debate on how it is used by society, including its widespread application in doses larger than the officially recommended upper limit.

Biological significance

File:Ascorbic acid.png

Top: ascorbic acid
(reduced form)
Bottom: dehydroascorbic acid
(oxidized form)

Main article: ascorbic acid

Vitamin C is a weak sugar acid, and is a carbon based compound of six carbon atoms structurally related to glucose. Vitamin C is the L-enantiomer of ascorbic acid. The opposite D-enantiomer shows no biological activity. Both are mirror image forms of the same chemical molecular structure (see optical isomers). L-ascorbic acid exists as two inter-convertible compounds: L-ascorbic acid, which is a strong reducing agent, and its oxidised derivative, L-dehydroascorbic acid.

The active part of the substance is the ascorbate ion, which is found either as a free acid or a salt that is neutral or slightly basic. Commercial vitamin C is often a mix of ascorbic acid, sodium ascorbate and/or other ascorbates. Most supplements contain a racemic mixture of both enantiomers, as the inactive form is harmless.

Function

• As a participant in hydroxylation, vitamin C is needed for the production of collagen in the connective tissue. These fibers are ubiquitous throughout the body, providing firm but flexible structure. Some tissues have a greater percentage of collagen, especially: skin, mucous membranes, teeth and bones.
• Vitamin C is required for synthesis of dopamine, noradrenaline and adrenaline in the nervous system or in the adrenal glands.
• Vitamin C is also needed to synthesize carnitine, important in the transfer of energy to the cell mitochondria.
• The tissues with greatest percentage of vitamin C — over 100 times the level in blood plasma — are the adrenal glands, pituitary, thymus, corpus luteum, and retina.
• The brain, spleen, lung, testicle, lymph nodes, liver, thyroid, small intestinal mucosa, leukocytes, pancreas, kidney and salivary glands usually have 10 to 50 times the concentration present in blood plasma.
• Vitamin C is an antioxidant and acts as a substrate for ascorbate peroxidase.

Natural mode of synthesis

Model of the vitamin C (L-ascorbic acid) molecule. Black is carbon, red is Oxygen and white is Hydrogen

Almost all animals and plants synthesize their own vitamin C. There are some exceptions, such as humans and a small number of other animals, including, apes, guinea pigs, the red-vented bulbul, a fruit-eating bat and a species of trout. This has led some scientists, including chemist Linus Pauling to hypothesize that these species lost the ability to produce their own vitamin C, and that if their diets were supplemented with an amount of the nutrient proportional to the amount produced in animal species that do synthesize their own vitamin C, better health would result. The species-specific loss of the ability to synthesize ascorbate strikingly parallels the evolutionary loss of the ability to break down uric acid. Uric acid and ascorbate are both strong reducing agents (electron-donors). This has led to the suggestion that in higher primates, uric acid has taken over some of the functions of ascorbate. Ascorbic acid can be oxidised (broken down) in the human body by the enzyme ascorbic acid oxidase.

Some microorganisms such as the yeast Saccharomyces cerevisiae have been shown to be able to synthesize vitamin C from simple sugars.

Deficiency disease

Scurvy (a form of avitaminosis) results from lack of vitamin C, which is required for correct collagen synthesis in humans. Scurvy leads to the formation of liver spots on the skin, spongy gums, and bleeding from all mucous membranes. The spots are most abundant on the thighs and legs, and a person with the ailment looks pale, feels depressed, and is partially immobilized. In advanced scurvy there are open, suppurating wounds and loss of teeth.

Scurvy was at one time common among sailors, pirates and others who were on ships that were out to sea longer than perishable fruits and vegetables could be stored and by soldiers who were similarly separated from these foods for extended periods. It was described by Hippocrates (c. 460 BC–c. 380 BC). Its cause and cure has been known in many native cultures since prehistory. For example, in 1536, the French explorer Jacques Cartier, exploring the St. Lawrence River, used the local natives' knowledge to save his men who were dying of scurvy. He boiled the needles of the arbor vitae tree (Eastern White Cedar) to make a tea that was later shown to contain 50 mg of vitamin C per 100 grams.

No bodily organ stores vitamin C, and so the body soon depletes itself if fresh supplies are not consumed through the digestive system.

Daily dosage requirements

There is continuing debate within the scientific community over the best dose schedule (the amount and frequency of intake) of vitamin C for maintaining optimal health in humans. It is generally agreed that balanced diet without supplementation contains enough vitamin C to prevent acute scurvy in an average healthy adult (those who are pregnant, smoke tobacco, or are under stress require slightly more).

Vitamin C is recognized to be one of the least toxic substances known to medicine, with the LD50 being 11,900 milligrams per kilogram. High doses (thousands of milligrams) may result in diarrhea, which is harmless if the dose is reduced immediately. Some researchers claim the onset of diarrhoea to be an indication of where the body’s true vitamin C requirement lies. Both Cathcart and Cameron have demonstrated that very sick patients with cancer or influenza do not display any evidence of diarrhoea at all until ascorbate intake reaches levels as high as 200 grams (half a pound).

Government recommended intake levels

United States vitamin C recommendations
Recommended Dietary Allowance (adult male)	90 mg per day
Recommended Dietary Allowance (adult female)	75 mg per day
Tolerable Upper Intake Level (adult male)	2000 mg per day
Tolerable Upper Intake Level (adult female)	2000 mg per day

Recommendations for vitamin C intake have been set by various national agencies:

• 40 milligrams per day — the United Kingdom's Food Standards Agency
• 45 milligrams per day — the World Health Organization
• 60-95 milligrams per day — United States' National Academy of Sciences

The United States defined Tolerable Upper Intake Level for a 25-year old male is 2000 milligrams per day.

Independent recommended intake levels

Some independent researchers have calculated the amount needed for an adult human to achieve similar blood serum levels as vitamin C synthesising mammals as follows:

• 400 milligrams per day — the Linus Pauling Institute and the US National Institutes of Health
• 500 milligrams per 12 hours — Professor Roc Ordman, from research into biological free radicals
• 3,000 milligrams per day (or more during illness or pregnancy, sometimes up to 300,000 mg) — the Vitamin C Foundation
• 6,000–12,000 milligrams per day — Thomas Levy, Colorado Integrative Medical Centre
• 6,000–18,000 milligrams per day — Linus Pauling's person use
• 3,000–200,000 milligrams per day — Robert Cathcart's protocol known as a "vitamin C flush" wherein escalating doses of vitamin C are given until diarrhoea develops, then choosing the highest dose that does not cause diarrhoea (the bowel tolerance threshold)

Testing for ascorbate levels in the body

Simple tests exist for measurng the levels of vitamin C in the urine and in serum or blood plasma. However these do not accurately reflect actual tissue ascorbate levels. Reverse phase high performance liquid chromatography is used for determining the storage levels of vitamin C within lymphocytes and tissue.

It has been observed that while serum or blood plasma levels follow the circadian rhythm or short term dietary changes those within tissues themselves are more stable and give a better view of the availability of ascorbate within the organism. However, very few hospital laboratories are adequately equipped and trained to carry out such detailed analyses, and require samples to be analyzed in specialized laboratories.

Vitamin C as a macronutrient

Linus Pauling's popular and influential book How to Live Longer and Feel Better, first published in 1986, advocated very high doses of vitamin C.

Main article: Vitamin C megadosage

There is a strong advocacy movement for large doses of vitamin C, despite not all purported benefits being supported by the medical community. Many pro-vitamin C organizations promote usage levels well beyond the current Dietary Reference Intake.

There exists an extensive and growing literature critical of governmental agency dose recommendations.

The main arguments center around the fact that the biological halflife for vitamin C is quite short, about 30 minutes in blood plasma, a fact which high dose advocates say that mainstream researchers have failed to take into account. Researchers athe National Institutes of Health decided upon the current RDA based upon tests conducted 12 hours (24 half lives) after consumption. Steve Hickey, on this matter says "To be blunt, the NIH gave a dose of vitamin C, waited until it had been excreted, and then measured blood levels."

The established RDA is thought to be one that will prevent the onset of scurvy and is not necessarily the most optimal dosage.

Therapeutic applications of high doses

Since its discovery vitamin C has been considered a universal panacea by some, although this led to suspicions of it being overhyped by others. It has been hypothosised that the vitamin can protect against:

• Common cold
• Polio
• Heart disease
• Viral diseases
• Poisons
• Lead poisoning
• Cancer
• Cataracts
• Autism

Natural and artificial dietary sources

Vitamin C is obtained through the diet by the vast majority of the world's population. The richest natural sources are fruits and vegetables, and of those, the camu camu fruit and the billygoat plum contain the highest concentration of the vitamin. It is also present in some cuts of meat, especially liver. Vitamin C is the most widely taken nutritional supplement and is available in a variety of forms, including tablets, drink mixes, crystals in capsules or naked crystals.

Plant sources

Rose hips are a particularly rich source of vitamin C

Citrus fruits (orange, lemon, grapefruit, lime), tomatoes, and potatoes are good common sources of vitamin C. Other foods that are good sources of vitamin C include papaya, broccoli, brussels sprouts, black currants, strawberries, cauliflower, spinach, cantaloupe, kiwifruit, cranberries and red peppers.

Emblica officinalis often referred to as Indian gooseberry or amla, is one of the richest known sources of vitamin C (720 mg/100 g of fresh pulp or up to 900 mg/100 g of pressed juice. — it contains 30 times the amount found in oranges.

The amount of vitamin C in foods of plant origin depends on:

• the precise variety of the plant,
• the soil condition
• the climate in which it grew,
• the length of time since it was picked,
• the storage conditions,
• the method of preparation. Cooking in particular is often said to destroy vitamin C — but see the section on Food preparation.

The following table is approximate and shows the relative abundance in different raw plant sources. The amount is given in milligrams per 100 grams of fruit or vegetable (for comparison, one 5 ml teaspoon of pure vitamin C powder weighs 5,000 milligrams).

Plant source	Amount (mg/100 g)
Billy Goat plum	3150
Camu Camu	2800
Wolfberry	2500
Rose hip	2000
Acerola	1600
Amla	720
Jujube	500
Baobab	400
Blackcurrant	200
Red pepper	190
Parsley	130
Seabuckthorn	120
Guava	100
Kiwifruit	90
Broccoli	90
Loganberry	80
Redcurrant	80
Brussels sprouts	80
Lychee	70
Cloudberry	60
Persimmon	60

Plant source	Amount (mg/100 g)
Papaya	60
Strawberry	60
Orange	50
Lemon	40
Melon, cantaloupe	40
Cauliflower	40
Grapefruit	30
Raspberry	30
Tangerine	30
Mandarin orange	30
Passion fruit	30
Spinach	30
Cabbage raw green	30
Lime	20
Mango	20
Potato	20
Melon, honeydew	20
Mango	16
Tomato	10
Blueberry	10
Pineapple	10

Plant source	Amount (mg/100 g)
Pawpaw	10
Grape	10
Apricot	10
Plum	10
Watermelon	10
Banana	9
Carrot	9
Avocado	8
Crabapple	8
Peach	7
Apple	6
Blackberry	6
Beetroot	5
Pear	4
Lettuce	4
Cucumber	3
Eggplant	2
Fig	2
Bilberry	1
Horned melon	0.5
Medlar	0.3

Animal sources

Goats, like almost all animals, make their own vitamin C. An adult goat will manufacture more than 13,000 mg of vitamin C per day in normal health and as much as 100,000 mg daily when faced with life-threatening disease, trauma or stress.

The overwhelming majority of species of animals and plants synthesise their own vitamin C. Synthesis is achieved through a sequence of four enzyme driven steps, which convert glucose to vitamin C. It is carried out either in the kidneys, in reptiles and birds, or the liver, in mammals and perching birds. The last enzyme in the process, l-gulonolactone oxidase, cannot be made by humans because the gene for this enzyme is defective (Pseudogene ΨGULO). The evolutionary loss of the gene coding for this enzyme has occurred more than once, affecting most fish; many birds; some bats; guinea pigs; and most primates, including humans. The mutations have not been lethal because vitamin C is so prevalent in the surrounding food sources (many of these species' diet consists largely of fruit).

An adult goat, who possesses all the necessary genes will manufacture more than 13,000 mg of vitamin C per day in normal health and as much as 100,000 mg daily when faced with life-threatening disease, trauma or stress.

Trauma or injury has been demonstrated to use up large quantities of vitamin C in animals, including humans.

It was only realised in the 1920s that some cuts of meat and fish are also a source of vitamin C for humans. The muscle and fat that make up the modern western diet are, however, poor sources. As with fruit and vegetables, cooking degrades the vitamin C content.

Vitamin C is present in mother's milk and in less amounts in raw cow's milk (but pasteurized milk contains only trace amounts of the vitamin).

The following table shows the relative abundance of vitamin C in various foods of animal origin, given in mg of vitamin C per 100 grams of food:

Food	Amount (mg/100 g)
Calf liver (raw)	36
Beef liver (raw)	31
Oysters (raw)	30
Cod roe (fried)	26
Pork liver (raw)	23
Lamb brain (boiled)	17
Chicken liver (fried)	13
Lamb liver (fried)	12
Lamb heart (roast)	11

Food	Amount (mg/100 g)
Lamb tongue (stewed)	6
Human milk (fresh)	4
Goat milk (fresh)	2
Cow milk (fresh)	2
Beef steak (fried)	0
Hen's egg (raw)	0
Pork bacon (fried)	0
Calf veal cutlet (fried)	0
Chicken leg (roast)	0

Food preparation

It is important to choose a suitable method of food preparation that conserves vitamin C content. When cooking vegetables, one should seek to minimize temperature and duration of cooking and not discard water used in preparation (e.g. by steam cooking or by making soup). There is no discernible difference in health benefit between natural and synthetic forms of vitamin C (although fruits and vegetables contain various other nutrients, and vitamin C is not their only health benefit).

Recent observations suggest that the impact of temperature and cooking on vitamin C may have been overestimated, since it decomposes around 190–192°C, well above the boiling point of water:

1. Since it is water soluble, vitamin C will strongly leach into the cooking water while cooking most vegetables — but this doesn't necessarily mean the vitamin is destroyed — it's still there, but it's in the cooking water. (This may also suggest how the apparent misconception about the extent to which boiling temperatures destroy vitamin C might have been the result of flawed research: If the vitamin C content of vegetables (and not of the water) was measured subsequent to cooking them, then that content would have been much lower, though the vitamin has not actually been destroyed.)
2. Not only the temperature, but also the exposure time is significant. Contrary to what was previously and is still commonly assumed, it can take much longer than two or three minutes to destroy vitamin C at boiling point

It also appears that cooking doesn't necessarily leach vitamin C in all vegetables at the same rate; it has been suggested that the vitamin is not destroyed when boiling broccoli. This may be a result of vitamin C leaching into the cooking water at a slower rate from this vegetable.

Copper pots will destroy the vitamin.

Some research shows that fresh-cut fruit may not lose much of its nutrients when stored in the refrigerator for a few days.

Vitamin C enriched teas and infusions have increasingly appeared on supermarket shelves. Such products would be nonsense if boiling temperatures did indeed destroy vitamin C at the rate it had previously been suggested. It should be noted however that as of 2004 most academics not directly involved in vitamin C research still teach that boiling temperatures will destroy vitamin C very rapidly.

Vitamin C supplements

File:RedoxonVitaminC.jpg

Vitamin C is widely available in the form of tablets and powders. The Redoxon brand, produced by Hoffmann-La Roche was the first mass-produce synthetic vitamin C and was launched in 1934.

Vitamin C is the most widely taken dietary supplement. It is available in many forms including caplets, tablets, capsules, drink mix packets, in multi-vitamin formulations, in multiple anti-oxidant formulations, as chemically pure crystalline powder, time release versions, and also including bioflavonoids such as quercetin, hesperidin and rutin. Tablet and capsule sizes range from 25 mg to 1500 mg. Vitamin C (as ascorbic acid) crystals are typically available in bottles containing 300 g to 1 kg of powder (a teaspoon of vitamin C crystals equals 5,000 mg). In supplements, Vitamin C most often comes in the form of various mineral ascorbates, as they are easier to absorb, more easily tolerated and provide a source of several dietary minerals.

Artificial modes of synthesis

Vitamin C is produced from glucose by two main routes. The Reichstein process, developed in the 1930s, uses a single pre-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. Both processes yield approximately 60% vitamin C from the glucose feed.

Research is underway at the Scottish Crop Research Institute in the interest of creating a strain of yeast that can synthesise vitamin C in a single fermentation step from galactose, a technology expected to reduce manufacturing costs considerably.

World production of synthesised vitamin C is currently estimated at approximately 110,000 tonnes annually. Main producers today are BASF/Takeda, DSM, Merck and the China Pharmaceutical Group Ltd. of the People's Republic of China. China is slowly becoming the major world supplier as its prices undercut those of the US and European manufacturers.

Discovery and history

The need to include fresh plant food or raw animal flesh in the diet to prevent disease was known from ancient times. Native peoples living in marginal areas incorporated this into their medicinal lore. For example, infusions of spruce needles were used in the temperate zones, or the leaves from species of drought-resistant trees in desert areas. In 1536, the French explorer Jacques Cartier, exploring the St. Lawrence River, used the local natives' knowledge to save his men who were dying of scurvy. He boiled the needles of the arbor vitae tree to make a tea that was later shown to contain 50 mg of vitamin C per 100 grams.

Through history the benefit of plant food for the survival of sieges and long sea voyages had been occasionally recommended by authorities. John Woodall, the first appointed surgeon to the British East India Company, recommended the use of lemon juice as a preventive and cure in his book "The Surgeon's Mate" of 1617. The Dutch writer, Johann Bachstrom of Leyden, in 1734, gave the firm opinion that "scurvy is solely owing to a total abstinence from fresh vegetable food, and greens; which is alone the primary cause of the disease."

Citrus fruits were one of the first sources of vitamin C available to ship's surgeons.

The first attempt to give scientific basis for the cause of scurvy was by a ship's surgeon in the British Royal Navy, James Lind. While at sea in May 1747, Lind provided some crewmembers with two oranges and one lemon per day, in addition to normal rations, while others continued on cider, vinegar or seawater, along with their normal rations. In the history of science this is considered to be the first example of a controlled experiment comparing results on two populations of a factor applied to one group only with all other factors the same. The results conclusively showed that citrus fruits prevented the disease. Lind wrote up his work and published it in 1753, in Treatise on the Scurvy.

Lind's work was slow to be noticed, partly because he gave conflicting evidence within the book and partly because of social inertia in some elements at the British admiralty who saw care for the well-being of ships' crew as a sign of weakness. There was also the fact that fresh fruit was very expensive to keep on board, whereas boiling it down to juice allowed easy storage but destroyed the vitamin. Ships' captains assumed wrongly that it didn't work, because the juice failed to cure scurvy. (Indeed, boiling in copper kettles may have destroyed the vitamin.)

It was 1795 before the British navy adopted lemons or lime as standard issue at sea. Limes were more popular as they could be found in British West Indian Colonies, unlike lemons which weren't found in British Dominions, and were therefore more expensive. (This practice led to the nickname limey for British people, especially British sailors.) Captain James Cook had previously demonstrated and proven the principle of the advantages of fresh and preserved foods, such as sauerkraut, by taking his crews to the Hawaiian Islands and beyond without losing any of his men to scurvy. For this otherwise unheard of feat, the British Admiralty awarded him a medal. So, the Navy was certainly well aware of the principle. The cost of providing fresh fruit on board was probably a factor in this long delay. The Captains usually provided luxuries or non-standard supplies not provided by the Admiralty.

James Lind (1716 – 1794), a British Royal Navy surgeon who, in 1774, identified that a quality in fruit prevented the disease of scurvy in what was the first recorded controlled experiment.

The name "antiscorbutic" was used in the eighteenth and nineteenth centuries as general term for those foods known to prevent scurvy, even though there was no understanding of the reason for this. These foods include lemons, limes, and oranges; sauerkraut, salted cabbage, malt, and portable soup were employed with variable effect.

In 1907, Axel Holst and Theodor Frølich, two Norwegian physicians studying beriberi contracted aboard ship's crews in the Norwegian Fishing Fleet, wanted a small test mammal to substitute for the pigeons they used. They fed guinea pigs the test diet, which had earlier produced beriberi in their pigeons, and were surprised when scurvy resulted instead. Until that time scurvy had not been observed in any organism apart from humans, and it was considered an exclusively human disease.

Albert Szent-Györgyi, pictured here in 1948, was awarded the 1937 Nobel Prize in Medicine for the discovery of vitamin C

In the early twentieth century, the Polish-American scientist Casimir Funk conducted research into deficiency diseases, and in 1912 Funk developed the concept of vitamins, for the elements in food which are essential to health. Then, from 1928 to 1933, the Hungarian research team of Joseph L Svirbely and Albert Szent-Györgyi and, independently, the American Charles Glen King, first isolated vitamin C and showed it to be ascorbic acid. Although Szent-Györgyi was awarded the 1937 Nobel Prize in Medicine, many feel King is as responsible for its development.

In 1928 the arctic anthropologist and adventurer Vilhjalmur Stefansson attempted to prove his theory of how Eskimo (Inuit) people are able to avoid scurvy with almost no plant food in their diet. This had long been a puzzle because the disease had struck European Arctic explorers living on similar high-meat diets. Stefansson theorised that the native peoples of the Arctic got their vitamin C from fresh meat that was raw or minimally cooked. Starting in February 1928, for one year he and a colleague lived on an animal-flesh-only diet under medical supervision at New York's Bellevue Hospital; they remained healthy.

In 1933 – 1934, the British chemists Sir Walter Norman Haworth and Sir Edmund Hirst and, independently, the Polish Tadeus Reichstein, succeeded in synthesizing the vitamin, the first to be artificially produced. This made possible the cheap mass production of vitamin C. Haworth was awarded the 1937 Nobel Prize in Chemistry largely for this work. The synthetic form of the vitamin is identical to the natural form.

The Swiss pharmaceutical company Hoffmann-La Roche was the first to mass-produce synthetic vitamin C, under the brand name of Redoxon, in 1934.

In 1959 the American J.J. Burns showed that the reason some mammals were susceptible to scurvy was the inability of their liver to produce the active enzyme L-gulonolactone oxidase, which is the last of the chain of four enzymes which synthesize vitamin C.

American biochemist Irwin Stone was the first to exploit vitamin C for its food preservative properties and held patents on this. He developed the theory that vitamin C was an essential nutrient deficient in humans as a result of a genetic defect that afflicted the whole human race.

See also

• Ascorbic acid — for the chemistry of vitamin C
• Ascorbyl palmitate — an fat-soluble ester of vitamin C
• Ascorbyl stearate — another fat-soluble ester of vitamin C
• Dehydroascorbic acid — an oxidized form of vitamin C
• Erythorbic acid — a stereoisomer of vitamin C
• Mineral ascorbates — salts of vitamin C
• Uric acid — the loss of the ability to process uric acid in higher primates parallels the loss of the ability to synthesize vitamin C
• Vitamin C megadosage — for the arguments for and against the controversial theory of vitamin C being a "universal panacea"

General

• Anti-oxidant — chemicals that slow or prevent oxidation reactions, vitamin C being one
• Micronutrient — essential nutrients needed for life in small quantities
• Macronutrient — essential nutrients needed for life in large quantities
• Megavitamin therapy — the use of large amounts of vitamins, often many times greater than the recommended dietary allowance, in the prevention and treatment of diseases
• Orthomolecular medicine — the use of any natural substance found in a healthy diet in the prevention and treatment of diseases
• Vitamin — nutrients required in very small amounts for essential metabolic reactions in the body

References

• Pauling, Linus (1986) How to Live Longer and Feel Better W. H. Freeman and Company, ISBN 0-380-70289-4

• Levy Thomas (2002). Vitamin C, Infectious Diseases, and Toxins. Xlibris Corporation (Paperback). ISBN 1-4010-6963-0.(Note: Xlibris is a print on demand self-publishing house.)

• Hickey, Steve; Roberts, Hilary (May, 2004) Ascorbate: The Science of Vitamin C, Lulu Press, Inc. ISBN 1-4116-0724-4 (Note: Lulu is a print on demand self-publishing house.)

• Dolske, M.C., et al. 1993. "A preliminary trial of ascorbic acid as a supplemental therapy for autism." Prog. Neuropsychopharmacol. Biol. Psychiatry, 17(5):765–774.

• Green, V.A., K.A. Pituch, J. Itchon, A. Choi, M. O'Reilly, J. Sigafoos, "Internet survey of treatments used by parents of children with autism," Res Dev Disabil, 2006, 27(1):70–84.

Further reading

• Cancer and Vitamin C, Ewan Cameron and Linus Pauling, Pauling Institute of Science and Medicine, 1979
• The Healing Factor: Vitamin C Against Disease, Irwin Stone, Grosset and Dunlap
• Life Extension: A Practical Scientific Approach (Part IV, Chapter 7: Vitamin C), Durk Pearson and Sandy Shaw, Warner Books, 1982
• Life Extension Revolution, Saul Kent, Morrow, 1980
• Mind Food and Smart Pills: How to Increase Your Intelligence and Prevent Brain Aging (Chapter 3: Vitamin C, The Champion Free Radical Scavenger), Ross Pelton, 1986
• Vitamin C and the Common Cold, Linus Pauling, 1970
• Vitamin C, the Common Cold, and the Flu, Linus Pauling, Freeman, 1976
• Vitamin C, Volumes I, II, III., Monograph by C.A.B Clemetson, 1989 CRC Press, Boca Raton, Florida, ISBN 0-8493-4841-2

External links

• Jane Higdon, "Vitamin C", Micronutrient Information Center, Linus Pauling Institute, Oregon State University
• AscorbateWeb "An historical review of the medical & scientific literature attesting to the efficacy of Ascorbate (Ascorbic Acid, Cevitamic Acid, Sodium Ascorbate etc. a.k.a. “Vitamin C”) in the treatment and prevention of human and animal ills, conditions and diseases."
• Healing Thresholds - Summaries of research on Vitamin C and other autism therapies]
• U.S. patent 5,278,189 Prevention and treatment of occlusive cardiovascular disease with ascorbate and substances that inhibit the binding of lipoprotein (A), Inventors: Matthias W. Rath and Linus C. Pauling
• Natural food-Fruit Vitamin C Content
• United Kingdom Foods Standards Agency Official UK view on vitamin C.
• Vitamin C in human health and disease is still a mystery? An overview among all time most-viewed articles published by BioMed Central (free access)
• Vitamin C May Not Have Much Effect on Colds health.dailynewscentral.com Finding that 200 mg per day has little effect on colds but a single dose of 8 grams does.
• Vitamin C Requirements: Optimal Health Benefits vs Overdose A moderately high dose advocacy supporting site.
• Ascorbate and cancer Discussion of both historical and current uses of Vitamin C in cancer treatment
• For Doctors: Preparation of Vitamin C IV's—information gathered and presented by Andrew W. Saul, PhD.
• Information regarding treatment of the Bird Flu with massive doses of ascorbate. by Robert Cathcart, M.D.