Common cold vitamin

In more recent times, large doses of vitamin C have been claimed to prevent the common cold, cure infertility, delay the onset of symptoms in acquired immunodeficiency syndrome (AIDS), and inhibit the development of gastric and cervical cancers. None of these claims have been backed by medical evidence, however. In the largest study yet done of the effect of vitamin C on the common cojd, a meta-analysis of more than 100 separate trials covering 40,000 people found no difference in the incidence of colds between those who took supplemental vitamin G regularly and those who did not. When taken during a cold, however, vitamin C does appear to decrease the cold s duration by 8%. 

Vitamin C status is supposed to play a role in immune function and to influence the progression of some chronic degenerative diseases like atherosclerosis, cancer, cataracts, and osteoporosis. The role of vitamin C in immune function, especially during common cold and upper respiratory tract infection, is the subject of lively debate. The exact mechanisms of action have not yet been fully elucidated, but the results of several trials point to a reduced duration and intensity of infections in subjects consuming high amounts of vitamin C (200-1000 mg/d). However, the incidence of common cold was not influenced significantly (24). 

On the basis of available results, persons suffering from common cold might benefit from taking 1 -2 g/d of vitamin C. However, the usefulness of taking high amounts of vitamin C to prevent common cold has yet to be proven [2]. 

Vitamin C (ascorbic acid) is probably the most known vitamin in the world. Its legendary fame is based on the two events its exceptionally important role in the treatment of scurvy and Linus Pauling s proposal to use the huge doses of ascorbic acid for the prevention of common cold. The latter proposal, based obviously on the antioxidant properties of ascorbic acid, generated numerous studies and was frequently disputed, but many people (me including) successfully apply ascorbic acid for the treatment of starting stage of common cold. 

Douglas RM, Hemila H, ChaUcer E, Treacy B. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev 2007. 

Pauling, L. (1970) Vitamin C and the Common Cold, Freeman, San Francisco, California... 

Although there is much controversy about the exact requirement, the adult Recommended Daily Allowance of vitamin C is 70 mg per day. Some scientists and physicians have suggested doses up to 1 to 3 grams per day in order to help resist the common cold. Deficiency of vitamin C results in swollen joints, abnormal development and maintenance of tissue structures, and eventually scurvy. 

Pauling, in recent years, researched the chemistry of the brain and mental illness, the cause of sickle-cell anemia, and the effects of large doses of Vitamin C on the common cold and on cancer. On August 19, 1994, Pauling, himself, died of cancer at the age of 93. 

Vitamin C is well known for its role in the prevention of the deficiency disease scurvy (15,17-19). Its nonvitamin health promotion functions are still under investigation and remain controversial. They include the modulation of hypertension, ischemic heart disease, cancer, cataracts, immune responses, and the common cold (3,6,15,17,25-41). 

H Hcmila. Vitamin C, the placebo effect, and the common cold a case study of how preconceptions influence the analysis of results. J Clin Epidemiol 49 1079-1084, 1996. 

The long-standing interest in the properties of L-ascorbic acid is manifested by the fact that 1146 references related to vitamin C are listed for year 2000 in the PUB MED index in the Internet. The most popular use of L-ascorbic acid is for prevention and treatment of the common cold, but this role remains controversial. In a recent review, the authors conclude that the long-term daily supplementation with large doses of vitamin C does not appear to prevent colds, but there is a modest therapeutic effect on the duration of cold symptoms.369... 

It is used in the treatment of scurvy, postoperative cases, and healing bedsores and chronic leg ulcers. Vitamin C increases the absorption of iron during anemia and is frequently combined with ferrous salts. It is used in urinary tract infections to acidify urine. Large doses of vitamin C have been tried to cure everything from the common cold to cancer, with not much success. The usefulness of vitamin C in asthma, cancer, atherosclerosis, psychologic symptoms, and fertility is doubtful. Ascorbic acid is well tolerated in large doses and may cause rebound scurvy on withdrawal. There is a possibility of forming urinary stones. 

Vitamin C cannot be synthesized in the human body and must be obtained from the diet (e.g., citrus fruits, broccoli, turnip greens, sweet peppers, tomatoes) or by taking synthetic vitamin C (e.g., vitamin C tablets, high-C drinks, and other vitamin C-fortified commercial foods). The minimum recommended adult daily requirement of vitamin C to prevent scurvy is 60 mg. Some people, among them the late Linus Pauling, twice Nobel Laureate, suggested that very large daily doses (250 to 10,000 mg) of vitamin C could help prevent the common cold, or at least lessen the symptoms for many individuals. No reliable medical data support this claim. At present, the human quantitative requirement for vitamin C is still controversial and requires further research. 

Pauling finally wearied of trying to convince medical professionals about the benefits of megadoses of vitamin C and took his case directly to the public. His book, Vitamin C and the Common Cold, was a best seller. Sales of the vitamin soared. Nevertheless, his dispute with physicians persisted, with Pauling advocating for huge doses of vitamin C and the medical profession pooh-poohing his ideas. 

Douglas, Robert M. and Harri Hemila. Vitamin C for Preventing and Treating the Common Cold. PLoS Medicine 2 (6) (2005) el68. Also available online. URL http //medicine.plosjournals. org/perlserv/ request=get-document doi=10.1371/journal. pmed.0020168. Accessed on May 26, 2007. 

High doses of vitamin C are popularly recommended for the prevention and treatment of the common cold. Evidence from controlled trials is unconvincing. Chalmers (1975) reviewed 15 reports and considered that only 8 reports met the basic criteria of well-conducted scientific research. Assessment of these 8 reports gave no evidence of any beneficial effects. Similarly, Dykes and Meier (1975), reviewing only those reports that had been published in peer-reviewed journals, concluded that there was no evidence of any significant benefit. 

Hemila H (1992) Vitamin C and the common cold. British Journal of Nutrition 67, 3-16. 

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