Honestly, how many of you have vitamin D as a therapy released by your doctor? I imagine many! How many of you, however, really know this particular vitamin? I'm pretty sure most people aren't sure what they're taking.
Let's start by saying that there are five vitamins D, but the most important for us are vitamin D2 and D3, ergocalciferol and cholecalciferol, respectively. As far as D3 is concerned, we mainly assume it with the intake of products of animal origin, while D2 with foods of vegetable origin.
In both cases, these vitamins need sunlight to perform their function. Already at this point we can understand how the integration of these hormonal precursors, especially in winter, is useful if we expose ourselves to sunlight, otherwise we would not be able to make them perform their function. They are all fat-soluble, so they need lipid molecules (fat) to be conveyed and absorbed. Why do you think they are mainly found in mainly fatty foods? But let's go in order.
In their metabolization both the liver, which allows an initial transformation and splitting, and the kidneys, which complete the metabolic process, come into play. Not only that, vitamin D, we we self-produce it with exposure to sunlight, and that's why in the summer our blood values are always (or almost) in the laboratory ranges, while in winter it is prescribed as a supplement. If you have noticed, in one of the most beautiful films of all time, "The Truman Show" the protagonist played by Jim Carrey has to constantly take large amounts of vitamin D. This is because lives in an artificial world and designed like a film set and the sun is also artificial.
We said that we can also find a source of this vitamin in food, but which ones? As for the typology 3 we find a very good quantity in thecod liver oil, in fatty fish such as salmon, sardines, herring, in eggs and more precisely in the yolk, in pork and veal, especially in the liver, but also with very good quantities in milk and dairy products such as especially soft cheeses.
With regard to the variant 2, i vegetables with more abundance are all green leafy vegetables and mushrooms. Attention, being a thermolabile molecule, ie that changes its chemical structure with a change in temperature, alla food cooking which implies a partial loss. How does vitamin D help us? This molecule helps incalcium absorption and bone mineralization. This is why it should not be taken by those subjects who take some particular drugs such as prazoli containing aluminum or calcium or potassium sparing diuretics, or simple magnesium.
Like all things, however, also a excessive use or intake can cause problems, such as hypercalcemia (too much calcium in the blood) e calciuria (calcium in the urine), all things that shouldn't happen. It is also interesting to understand how we arrived at the current considerations on this molecule in the medical field and how interest is currently manifested in this historical period of the pandemic.
Does it have a tangible impact on COVID-19 prevention or not?
Let's start with yours discovery, we are in Germany in the 30s, the relations of the main world nations had already been severely tested by the First World War and people lived in the hope of a recovery and without the idea that, shortly after, world spirits will once again overheat.
There was even collaboration and healthy competition. Adolf Otto Reinhold Windaus (A. Windaus) is credited with discovering the structure of vitamin D, a German physician and chemist who was awarded the Nobel Prize in chemistry in 1928 and a pupil of a certain Hermann Emil Fischer, who was also a Nobel prize winner in chemistry 26 years earlier (1902). Windaus' studies were based on the hypotheses and theories of other scientists, first of all a certain Kurt Huldschinsky, a German pediatrician with Polish origins who already in 1919, studying children with rickets (a pathology that manifests itself with a delay in the bone and physical growth of children due to a lack of calcium assimilation) he noticed that they improved visibly and even healed if subjected to ultraviolet light. The same thing was noticed by an English doctor in the same years, a certain Edward Mellanby, but by comparing dogs grown indoors with stray dogs, more inclined to stay outdoors. Dogs raised indoors were smaller, with walking problems already in adulthood and visibly weaker.
A few years later, around 1923, an American biochemist, such Elmer McCollum, defined by Time Magazine as "Dr. Vitamin”, realized that there must be a correlation between some molecule and bone metabolism. He focused on fish liver oil, and this was the compound from which he started to find this anti-rachitic molecule.
Coming to the present day, we find ourselves facing a very dramatic health situation. Although SARS-CoV-2 belongs to a "family" of viruses (Coronavirus) known to us, which ranges from more harmless parasites to some decidedly more dangerous ones, our immune defenses are not able to deal with it properly, as it is unknown . Our organism reacts in a decidedly effective way to the viruses that we know and with which we can come into contact or that we have even faced once before, as we develop antibodies that remember that particular type of virus and array specific defenses to he.
For more particular viruses or viruses that are dangerous but difficult to find in our daily lives, we have vaccines available that create specific immunity for that virus. It is as if we force our immune system to create defenses in case it is needed. Not only that, the vaccine allows us to drastically reduce the chances of contracting that virus and also to have milder symptoms in case we should contract it. As for the usage of supplements such as vitamin D, to date (May 2021) there is no evidence of efficacy in the prevention of the disease.
Using it as a hypothetical aid to the immune system, or as a fortifier of the same has no scientific value. Like he didn't have before this pandemic. Some studies show, however, that there is a correlation between the deficiency of this vitamin and the increased risk of respiratory infections. Being the COVID a pathology with prevalent pulmonary interest, correlation with vitamin D deficiency and severity of the disease has been found also taking into account hospitalization and mortality rates as parameters. In other words, only in the case of vitamin D deficiency and the simultaneous presence of Sars-CoV-2 infection can there be more chances that the disease will have a worse course. We also remind you that, if the vitamin D values fall within the parameters, it will not be necessary to supplement it, since, as we have seen before, even an excess amount may be unsuitable for a health condition.
