"Hoaxes and disinformation are very dangerous when they concern health and it is often not easy to distinguish them among millions of pieces of information”: thus the Ministry of Health warns, the Italians, on its institutional site, from taking initiatives and treatments following the chimeras of the marketing offices of companies that promote unthinkable anticovid therapies and worse still healings by resorting to do-it-yourself.
And among the most widespread fake news he inserts the belief that taking a lot of vitamin C prevents contagion from new coronavirus. The ministry is categorical: absolutely not! "Taking the correct amount of vitamins through a correct and balanced diet - underlines the ministerial note - is important for health, instead take more vitamins than you normally need, for example by taking food supplements if you are not in a situation of vitamin deficiency, it can even be harmful. This is attested by the report of the Istituto Superiore di Sanità “Food supplements or drugs? Regulations and recommendations for conscious use in times of Covid-19" which highlights that food supplements "can be used to improve the well-being of healthy subjects, but their use for therapeutic purposes is improper and potentially dangerous for health ”.
And the Policlinico Gemelli which makes it clear that the intake of vitamin C supplements or le orange juice, lemon, kiwi, do not protect against COVID-19. THEExpert opinion on this point is unanimous. “And yet, the latter 'hoax' went viral, after the utterances of some influencers on social media and an audio message that circulates in WhatsApp chats (not to be broadcast at all), has led many to rob pharmacies and parapharmacies to grab vitamin C supplements. Too bad it's useless against COVID-19; and even a healthy diet, rich in fruit and vegetables, unfortunately cannot do much against this infection”.
Let's see then do some clarity going more specifically on the role of vitamin C or, as scientifically it should be called, ascorbic acid. Water-soluble molecule much talked about in recent years. Meanwhile, it might be strange for you to know that i classic foods to which we attribute this vitamin do not actually contain much of it. Listed below, we find the main common foods that we could find ourselves consuming in a food day. As we can see orange, lemon and pomegranate are particularly behind in the ranking. So why when we think of vitamin C do we associate it with orange or lemon? The references are calculated on 100 grams of product, and on average an orange weighs around 200 grams, consequently the vitamin C values also need to be doubled at least. It will be easier, and more common, to eat citrus fruits during the winter months than to consume grape juice daily, eating 300 g of kiwi rather than 100 g of currants. That's why when we talk about vitamin C, we link it to certain foods.
FOOD mg/100gr
Grapes (juice) 340
Chilli (fresh) 229
Currants (fresh) 200
Yellow peppers (raw) 167
Parsley (fresh) 162
Rocket (fresh) 110
Broccoli (raw) 110
Kiwi (fresh) 85
Strawberries (fresh) 54
Orange (fresh) 50
Lemon (fresh) 50
Grapefruit (fresh) 40
Ripe tomatoes (fresh) 25
Pineapple (fresh) 17
Apricots (dehydrated) 13
Watermelon (fresh) 8
Pomegranate (fresh) 8
As previously mentioned, vitamin C is water soluble, which means it dissolves in water, is rapidly absorbed from the gastrointestinal tract, and is regularly excreted from the body via renal excretion. That's why we need to introduce it with the diet since we can't synthesize it, like other animals do.
As can be seen from the table, the foods all have a statement on their state, i.e. fresh, raw or in juice. This is because vitamin C is thermolabile, meaning it is subject to oxidation, therefore destruction, if exposed to heat. Consequently, cooked foods will lose this molecule or will come to contain traces of it.
WedHow much should we assume? According to LARN (Reference Intake Levels of Nutrients) adults are enough between 75 and 60 mg per day. Still drawing from the table, it can be seen that one kiwi a day would be enough to satisfy this level.
Considering that we should take 5 portions of fruit and vegetables every day, it is really difficult to have deficiencies. It must be noted that scurvy, a condition that is recorded in the condition of avitaminosis relative to C, has now disappeared, also thanks to the decidedly changed lifestyles (for the better) from the post-war period to today.
Furthermore, the bioavailability appears to be different if introduced through food or multivitamin supplements. This is not due to the nature of the compound, being chemically equal, but given by the concentration. By eating fruit and vegetables and assuming to introduce a maximum of 500 mg of vitamin C, its bioavailability will be between 70 and 90%. With large doses such as supplements provide (> 1 gram), the permeability is even lowered to 50%, with consequent stagnation in the intestinal lumen. Consequently, it is understood that the higher its income, the lower its possibility of being absorbed. In addition, when the saturation level is reached, the renal excretion of this vitamin increases, even remaining completely intact.
Be careful when it comes to dosage: unlike fat-soluble vitamins, which have the possibility of accumulating in our body, water-soluble ones have a continuous turnover. Even in this case, however, we can go against cases of overdose. Some medical trials have high-dose treatment periods. In these cases cases of kidney stones, diarrhea and general intestinal disturbances have been documented. The maximum possible amount we can absorb is 2 grams, well beyond the necessary daily quota. Further quantities are not absorbed by the body and become waste material.
Why should we take vitamin C? This particular molecule is useful in redox reactions (this is why it is called an antioxidant), it intervenes in the production of collagen, it assists some metabolic reactions where other macromolecules are involved such as fats, proteins and glycides, favoring the absorption of iron, it also supports the formation of antibodies by the immune system, improves respiratory function and improves wound healing.
Do you want to know a little trick to be able to take more vitamin C with less product? No multivitamin supplements but juices, extracts, centrifuges and juices. At equal weight, the liquid makes up less volume than the solid, 200 ml of orange juice will not occupy the same place as 200 g of whole orange.
