It is widely believed that when you have a cold, you should eat foods with a high content of vitamin C, as well as take large doses of ascorbic acid to speed up recovery. We decided to check whether there is evidence of the medicinal properties of this vitamin.
By data Analytical company Nielsen, vitamins are the first most popular product in online pharmacies. In regular pharmacies, vitamin C, or ascorbic acid, as it is called in everyday life, is most often sold directly at the checkout or offered with any purchase. Bloggers And manufacturers vitamins at the first sign of a cold, it is advised to take vitamin C. According to some treatment regimens, you should immediately accept loading dose, and then maintain the level, others recommend distribute it into several doses throughout the day.
Ascorbic acid is an organic compound used not only in pharmacology, but also in food industry, cosmetology, analytical chemistry and even during development photos. S. Zilva received it from lemon juice, for the first time in crystalline form it was allocated in 1928 by the Hungarian-American chemist A. Szent-Györgyi from the adrenal glands of animals and from several plants, and in 1933, thanks to W. Haworth, it became the first synthesized vitamin. Both Szent-Gyorgyi and Haworth received Nobel Prizes for their discoveries: Szent-Gyorgyi in physiology or medicine, and Haworth in chemistry.
In medicine, ascorbic acid has many indications for use: hypovitaminosis C, diathesis, bleeding, including nasal, pulmonary, uterine, intoxication, including chronic intoxication with iron preparations, alcoholic and infectious delirium, acute radiation sickness, liver diseases (Botkin's disease, chronic hepatitis and cirrhosis), gastrointestinal diseases (achylia, peptic ulcer especially after bleeding, enteritis, colitis) and etc. Recommended for physical and mental overload, after fractures and burns, as well as during pregnancy (especially multiple births).
The claim that vitamin C strengthens the immune system and helps treat colds is widely spread in 1970 - after the publication of the book “Vitamin C and Health” by Nobel laureate in chemistry and Nobel Peace Prize winner Linus Carl Pauling. The scientist, relying only on theoretical reasoning and a selective approach to sources, calculated the required daily dose for a person in 5 g. His book became a real bestseller, and in 1972 he created and headed the Institute for the Development of Methods for Extending Life. In addition to using high doses of vitamin C to strengthen the immune system and protect against colds, Linus Pauling proposed using it to prolong the life of cancer patients and treat atherosclerosis, diabetes and gout. However, none of his experiments were ever considered a reliable clinical trial.
To understand whether vitamin C has a positive effect on the immune system, you need to understand how the immune system works, protecting a person from various pathogens (bacteria, viruses, fungi, cancer cells). Immunity is divided into innate (phagocytes, leukocytes) and acquired (antibodies). Phagocytes and white blood cells are able to accumulate vitamin C. It, in turn, protects these types of cells from oxidative damage and the negative effects of free radicals. When a pathogen enters the body, leukocytes produce substances (hypochlorous acid and peroxynitrite), which, while killing the pathogen, can damage the cells themselves. Antioxidant properties of vitamin C contribute in this case, protecting cells of the immune system from self-harm. Also ascorbic acid increases production of interferons by leukocytes, increases chemotactic (motor) ability of phagocytes and, according to some data, helps to increase the number of lymphocytes responsible for recognizing and destroying the pathogen. Thus, vitamin C does play an important role in the functioning of the immune system.
At the same time, the daily need for it amounts to 90 mg per day for men and 75 mg for women. Some factors increase the body's need for ascorbic acid: pregnancy (85 mg required), lactation (120 mg), and smoking (additional 35 mg). Thus, the maximum required dose will be 155 mg in a woman who is simultaneously breastfeeding and smoking. At the same time, vitamin C There is in many vegetables and fruits. For example, one orange contains about 80% of the daily value, one green bell pepper contains about 100%, and broccoli contains 107%. Vitamin C does not accumulate in the body, but is excreted by the excretory system. So if you have a varied diet, there is no need or point in using it in the form of supplements.
The Cochrane Review (a key source of information in the field of evidence-based medicine) is confirms: “Regular intake of vitamin C [at dosages of 200 mg] had no effect on the incidence of colds in the general population, based on 29 comparisons from clinical trials involving 11,306 participants.” However, the researchers continued, "regular vitamin C supplementation had a modest but consistent effect of reducing the duration of cold symptoms, based on 31 comparisons from studies of 9,745 cold episodes." As a result, the authors conclude that further clinical studies are needed to conclude whether vitamin C is effective in treating colds.
Scientists from the Cochrane Collaboration also conducted study, in which 11,000 children and adults took part. Those who took at least 200 mg of vitamin C per day had, on average, only 10% fewer cold symptoms, meaning that for an average illness of ten days, they recovered in nine.
Moreover, an analysis of seven studies found that proventhat taking vitamin C after the onset of symptoms is no more effective than taking a placebo.
It is important to note that significantly exceeding the daily dose is dangerous. Excess vitamin C can bring to the occurrence of kidney stones, call nausea, vomiting and allergies reactions.
So, while vitamin C does play an important role in our immune system, the required daily intake can be obtained from food without resorting to supplements. Regular preventive intake of vitamin C in a dosage of 200 mg or more slightly reduces the duration of a cold and its severity, but it is useless to start taking vitamin C after already feeling the symptoms of a cold.
Mostly not true
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