vitamin c vitamin c vitamin c (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical "serum" ingredient to treat melasma (dark pigment spots) and wrinkles on the face. it is used to prevent and treat scurvy. vitamin c is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. it is required for the functioning of several enzymes and is important for immune system function. it also functions as an antioxidant. most animals are able to synthesize their own vitamin c. however, apes (including humans) and monkeys (but not all primates), most bats, some rodents, and certain other animals must acquire it from dietary sources. vitamin cclinical datapronunciation/əˈskɔːrbɪk/, /əˈskɔːrbeɪt, -bɪt/ trade namesascor, cevalin, othersother namesl-ascorbic acid, ascorbic acid, ascorbateahfs/drugs.commonographmedlineplusa682583license data us dailymed: ascorbic_acid routes ofadministrationby mouth, intramuscular (im), intravenous (iv), subcutaneousatc codea11ga01 (who) a11gb01 (who) g01ad03 (who) s01xa15 (who)legal statuslegal status au: unscheduled uk: pom (prescription only) / gsl us: ℞-only / otc/ dietary supplement pharmacokinetic databioavailabilityrapid and completeprotein bindingnegligibleelimination half-lifevaries according to plasma concentrationexcretionkidneyidentifiers iupac name l-threo-hex-2-enono-1,4-lactoneor(r)-3,4-dihydroxy-5-((s)- 1,2-dihydroxyethyl)furan-2(5h)-one cas number50-81-7 yas salt: 134-03-2 ypubchem cid54670067as salt: 23667548iuphar/bps4781drugbankdb00126 yas salt: db14482 ychemspider10189562 yas salt: 16736174 yuniipq6ck8pd0ras salt: s033eh8359 ykeggd00018 yas salt: d05853 ychebichebi:29073 yas salt: chebi:113451 ychemblchembl196 yas salt: chembl591665 yniaid chemdb002072pdb ligandasc (pdbe, rcsb pdb)e numbere300 (antioxidants, ...) comptox dashboard (epa)dtxsid5020106 echa infocard100.000.061 chemical and physical dataformulac6h8o6molar mass176.124 g·mol−13d model (jsmol)interactive imagedensity1.694 g/cm3melting point190 to 192 °c (374 to 378 °f) (some decomposition)boiling point552.7 °c (1,026.9 °f) smiles oc(o)1oc(=o)c(o)=c1o inchi inchi=1s/c6h8o6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10h,1h2/t2-,5+/m0/s1 ykey:ciwbshskhkdkbq-jlaznsocsa-n y (verify) there is some evidence that regular use of supplements may reduce the duration of the common cold, but it does not appear to prevent infection. it is unclear whether supplementation affects the risk of cancer, cardiovascular disease, or dementia. it may be taken by mouth or by injection. vitamin c is generally well tolerated. large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin. normal doses are safe during pregnancy. the united states institute of medicine recommends against taking large doses. vitamin c was discovered in 1912, isolated in 1928, and in 1933, the first vitamin to be chemically produced. it is on the world health organization's list of essential medicines. vitamin c is available as an inexpensive generic and over-the-counter medication. partly for its discovery, albert szent-györgyi and walter norman haworth were awarded the 1937 nobel prizes in physiology and medicine and chemistry, respectively. foods containing vitamin c include citrus fruits, kiwifruit, guava, broccoli, brussels sprouts, bell peppers, potatoes, and strawberries. prolonged storage or cooking may reduce vitamin c content in foods. definition vitamin c is an essential nutrient for certain animals including humans. the term vitamin c encompasses several vitamers that have vitamin c activity in animals. ascorbate salts such as sodium ascorbate and calcium ascorbate are used in some dietary supplements. these release ascorbate upon digestion. ascorbate and ascorbic acid are both naturally present in the body, since the forms interconvert according to ph. oxidized forms of the molecule such as dehydroascorbic acid are converted back to ascorbic acid by reducing agents. vitamin c functions as a cofactor in many enzymatic reactions in animals (including humans) that mediate a variety of essential biological functions, including wound healing and collagen synthesis. in humans, vitamin c deficiency leads to impaired collagen synthesis, contributing to the more severe symptoms of scurvy. another biochemical role of vitamin c is to act as an antioxidant (a reducing agent) by donating electrons to various enzymatic and non-enzymatic reactions. doing so converts vitamin c to an oxidized state - either as semidehydroascorbic acid or dehydroascorbic acid. these compounds can be restored to a reduced state by glutathione and nadph-dependent enzymatic mechanisms. in plants, vitamin c is a substrate for ascorbate peroxidase. this enzyme utilizes ascorbate to neutralize excess hydrogen peroxide (h2o2) by converting it to water (h2o) and oxygen. deficiency main article: scurvy vitamin c blood serum levels are considered saturated at levels > 65 μmol/l (1.1 mg/dl), achieved by consuming amounts which are at, or above, the recommended dietary allowance, while adequate levels are defined as ≥ 50 μmol/l. hypovitaminosis of vitamin c is defined as ≤ 23 μmol/l and deficiency occurs at ≤ 11.4 μmol/l. for those 20 years of age or above, data from the u.s. 2003-04 national health and nutrition examination survey showed mean and median serum concentrations of 49.0 and 54.4 μmol/l, respectively. the percent of people reported as deficient was 7.1%. 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. scurvy is characterized by spots on and bleeding under the skin, spongy gums, 'corkscrew' hair growth, and poor wound healing. the skin lesions 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, loss of teeth, bone abnormalities and, eventually, death. 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 ascorbic acid 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. people in sepsis or septic shock may have micronutrient deficiencies, including low levels of vitamin c. medical uses vitamin c supplements at a drug store. 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 reporting conflicting results. a 2012 cochrane review reported no effect of vitamin c supplementation on overall mortality. it is on the world health organization's list of essential medicines. scurvy the disease scurvy is caused by vitamin c deficiency and can be prevented and treated with vitamin c-containing foods or dietary supplements. it takes at least a month of little to no vitamin c before symptoms occur. early symptoms are malaise and lethargy, progressing to shortness of breath, bone pain, bleeding gums, susceptibility to bruising, poor wound healing, and finally fever, convulsions and eventual death. until quite late in the disease the damage is reversible, as healthy collagen replaces the defective collagen with vitamin c repletion. treatment can be oral supplementation of the vitamin or by intramuscular or intravenous injection. scurvy was known to hippocrates in the classical era. the disease was shown to be prevented by citrus fruits in an early controlled trial by a royal navy surgeon, james lind, in 1747, on board hms salisbury. from 1796 onward, lemon juice was issued to all royal navy crewmen. common cold further information: vitamin c and the common cold the nobel prizewinner linus pauling advocated taking vitamin c for the common cold in a 1970 book. research on vitamin c in the common cold has been divided into effects on prevention, duration, and severity. a cochrane review which looked at at least 200 mg/day concluded that vitamin c 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 vitamin c on a regular basis did reduce the average duration by 8% in adults and 14% in children, and also reduced severity of colds. a subset of trials in adults reported that supplementation reduced the incidence of colds by half in marathon runners, skiers, or soldiers in subarctic conditions. another subset of trials looked at therapeutic use, meaning that vitamin c was not started unless the people started to feel the beginnings of a cold. in these, vitamin c did not affect duration or severity. an earlier review stated that vitamin c did not prevent colds, did reduce duration, did not reduce severity. the authors of the cochrane review concluded that: the failure of vitamin c supplementation to reduce the incidence of colds in the general population indicates that routine vitamin c supplementation is not justified … regular supplementation trials have shown that vitamin c reduces the duration of colds, but this was not replicated in the few therapeutic trials that have been carried out. nevertheless, given the consistent effect of vitamin c on the duration and severity of colds in the regular supplementation studies, and the low cost and safety, it may be worthwhile for common cold patients to test on an individual basis whether therapeutic vitamin c is beneficial for them." vitamin c distributes readily in high concentrations into immune cells, has antimicrobial and natural killer cell activities, promotes lymphocyte proliferation, and is consumed quickly during infections, effects suggesting a prominent role in immune system regulation. the european food safety authority found a cause and effect relationship exists between the dietary intake of vitamin c and functioning of a normal immune system in adults and in children under three years of age. several studies found vitamin c to have specific antiviral effects in which it inactivates the rna or dna of viruses or in the assembly of the virus. covid-19