Italian big consumers of vitamin C. More than thirty "years after Pauling's first books, despite the dry denials by conventional medicine, the" myth of "ascorbic acid - panacea for all ills" is hard to fade. There are those who recommend it in a completely disinterested way for the precious benefits experienced firsthand, those who improvise themselves as a scholar and researcher, and even those who raise conspiratorial hypotheses about alleged attempts to cloud its therapeutic properties.
Official medicine, for its part, can only warn against excessive enthusiasm for vitamin supplements; if for ascorbic acid the risks of side effects from overdose are particularly low, the same cannot be said for equally popular vitamins. such as E or pro-vitamin A (Beta-carotene).
As far as ascorbic acid is concerned, a dietary intake of 60/90 mg per day is considered sufficient to satisfy the needs of an adult in good health. A quantity, this, after all, negligible, easily bridged with simple daily consumption. of a kiwi or an orange.
As for vitamin C supplements, according to ministerial directives, the daily dosage cannot exceed 1,000 mg of ascorbic acid (one gram per day).
How Much Vitamin C Do You Get Through Supplements?
According to the thesis of mainstream medicine, a "varied and balanced diet is capable of providing all the nutrients necessary for the proper functioning of the body" by itself. The same thing also applies to the athlete, who despite "consuming more" is led to eat in a richer way, consequently increasing the intake of various nutrients.
The fruit of Ferdinandian Terminalia, an Australian plant, is the richest natural source of vitamin C, which contains at dosages equal to 3.1 g per 100. Among the foods commonly consumed in our country, kiwis and broccoli, with their 90 mg of vitamin out of 100, are the most generous sources in this regard.
According to the so-called health thesis, by virtue of the precious antioxidant properties of ascorbic acid, a regular and constant integration of variable quantities between 180 and 1000 mg per day (0.18 / 1 gram) is recommended.
To tell the truth, there are also those who - referring to the more well-known ex-consumer of ascorbic acid, the aforementioned Linus Pauling - come to consume it in "industrial" quantities, in the "order of 6-18 grams per day (the dosage is established by researching for repeated tests the maximum amount that can be taken without gastrointestinal disorders arising).
Also according to official medicine, the maximum daily intake limit, which most likely does not present any risk of adverse effects in most healthy subjects, is 2000 mg. This threshold refers to the total intake of vitamin C (food plus possible supplementation). The most important side effects that may appear at higher doses include headache, sleep disturbances, flushing of the face and gastrointestinal disorders (stomach acid, nausea, vomiting and diarrhea).
Ultimately, therefore, if we want to rely on the advice of official medicine, the supplementation of vitamin C is not necessary, but not even dangerous, unless you take real megadoses. Since often the truth lies in the middle, most some of the experts in favor of this practice recommend daily dosages ranging from 180/360 to 500/1000 mg / day.
Ascorbic acid and its salts: the many names of vitamin C.
Often, among the layman it is not clear that "L-ascorbic acid" is simply a synonym for "vitamin C" (while "D-ascorbic acid does not perform vitamin action). Let alone what happens when these people hear about of sodium, potassium, calcium aspartate and so on.
As the word itself says, ascorbic acid is an acid, and as such it can react with a base (for example sodium carbonate or potassium) forming a salt; this property is exploited in the industrial field to produce - through reactions and techniques rather simple - the salts of ascorbic acid. These products take the generic dome of mineral ascorbates and compared to pure vitamin C they are distinguished by a lower degree of acidity.
Absorption and bioavailability of ascorbic acid
Gastro-intestinal absorption of ascorbic acid occurs by simple diffusion and active transport. At low concentrations the active form predominates, while in the presence of high concentrations this mechanism becomes saturated and the contribution of passive diffusion becomes important.
At normal levels of intake, a portion of ascorbic acid ranging between 70 and 95% of the ingested dose is absorbed. However, this percentage may vary, even significantly, in relation to the dosage taken, moving towards 100% when the intake is particularly low and even falling below 20% when ascorbic acid is taken in very high doses (12 g) . On the basis of these physiological evidences, dividing the supplementary intake of vitamin C into several doses, to be taken at mealtimes, could theoretically increase the intestinal absorption of vitamin C. Once intestinal absorption has improved, one collides with a another obstacle, represented by the renal reabsorption threshold. In fact, if the plasma concentrations are too high, the excess vitamin C is rapidly removed from the organism through the urine; it is therefore important, always theoretically, that the gastro-intestinal absorption is gradual. In this way the little vitamin C that enters the circulation has time to be taken up by the cells in need, without accumulating too much with the risk of being eliminated Not surprisingly, a university professor ironically recalled that taking ascorbic acid at particularly high doses is an "excellent strategy to increase the cost of one's urine.
Is there a better form of ascorbic acid than the others?
Even if the classic marketing rules have now been overturned, the offer, as we know, always follows the demand. On the market, therefore, we find many products based on vitamin C, among whose ingredients "strange" terms appear very often, such as sodium ascorbate, potassium ascorbate, bioflavonoids and so on. The pure form, ascorbic acid, may be unwelcome on the palate due to its bitter taste. Moreover, due to its acidity, it can be poorly tolerated in the stomach. The main advantage of pure ascorbic acid is that it is the most concentrated form, in which each gram of product contains one gram of vitamin C. According to many experts in the field - who have no economic interest in promoting the purchase of alternative forms - ascorbic acid is without a doubt the formula with the best cost / benefit ratio.
As for ascorbates, the main limit is linked to the additional mineral intake, which may be contraindicated for some categories of individuals. One gram of sodium ascorbate, for example, provides 889 mg of ascorbic acid and 111 mg of sodium. Megadose sodium ascorbate can therefore excessively raise the sodium intake, still being harmless for healthy people but potentially dangerous for those who follow diets low in these minerals. In this case, potassium ascorbate should be preferred, which for each gram of ascorbic acid provides the body with 175 mg of potassium. Unlike sodium, potassium has a diuretic action; even in this case an additional intake does not cause particular problems for healthy people, but can be particularly dangerous for individuals with kidney disease or in therapy with potassium-sparing diuretics. Calcium ascorbate provides the organism with 114 mg of calcium per 1000 mg of ascorbic acid, and as such it can be of help in the prevention of osteoporosis (in any case, a total of 2500 mg of calcium per day should not be exceeded). Other common salts of ascorbic acid are magnesium ascorbate, manganese ascorbate, zinc ascorbate and molybdenum ascorbate.