VITAMIN D: How to Prevent Respiratory Infections
Importance of vitamin D during confinement #COVID
Scientific evidence shows that Vitamin D reduces the risk of contracting respiratory tract infections of both bacterial and viral origin.
Vitamin D supplements can help.
It is advisable to take 3000-4000 IU per day during confinement, which is equivalent to 75-100 μg/day.
Vitamin D can even help reduce the severity of such infections.
Where Vitamin D Is Found
Vitamin D is a fat-soluble vitamin like A and E.
It is found in fatty foods such as salmon, sardines, mackerel.
But, mostly, it is synthesized through the skin when we are EXPOSED TO THE SUN.
Sunbathing forms the precursor that enters the liver, hydroxylates and passes to the kidneys and forms the active vitamin.
Normally, this vitamin is known for facilitating the absorption of calcium.
I would like to take this opportunity to tell you something curious: The darker the skin, the slower vitamin D is produced.
From an anthropological point of view, the explanation is simple: humans who initially came from Africa migrated over the centuries to northern regions and with this, their skin became whiter, to be faster in synthesizing vitamin D, since with fair skin it takes less exposure time to produce this vitamin.
This phenomenon is part of an adaptive response of migratory origin.
Given the situation of the current confinement that we are experiencing, I invite you to reflect on how important what I have just commented is.
If we stay at home, it will be more difficult for us to synthesize vitamin D.
Vitamin D deficiency has been linked to increased severity of viral infections
And why is it more important than ever to have high levels of vitamin D?
Because Vitamin D supplements reduce the risk of these respiratory infections.
An example is the scientific evidence of a Meta-analysis published in the journal British Medical.
https://www.bmj.com/content/bmj/356/bmj.i6583.full.pdf
In this study, one of the things that is assessed is the levels of vitamin D in the blood that are measured with Vitamin D 25-OH.
If this vitamin is low, there is a greater risk of acute respiratory infections.
This information comes from randomized, double-blind, controlled studies conducted with a total of 10,933 people.
The study assessed, on the one hand, the effectiveness of those who took supplements.
If they took them 1 time a month, once a week or daily doses.
It was observed, based on the ODS Ratio, that those who took it 1 time a month reduced their risk of infection by 12%, those who took it in weekly or daily doses reduced the risk of infection by 19%.
But those who had deficient blood values below 25 nmoL/L, if supplemented weekly or daily, reduced their risk of infection by 70%. In other words, the risk of infections could be reduced by 70%.
Most of the population is deficient in Vitamin D.
In fact, in a study carried out on patients with Acute Respiratory Distress Syndrome , 95% of patients were deficient in vitamin D.
How Vitamin D Works
When there is an inflammatory process in the lungs, which is called ARDS (Acute Respiratory Distress Syndrome), the lungs fill with fluid and patients have difficulty breathing.
Explained in a simpler way: Imagine in the lungs the bronchi as a tree from which branches are coming out and at the end of these branches are the leaves.
The function of the alveolus is to pass oxygen into the blood and then collect CO2 on its return.
When there is an infection, the alveoli become inflamed and the respiratory system itself responds by expelling fluid into the tissue space.
This fluid subsequently enters the alveolus so that oxygen cannot enter the blood, nor CO2 return from the blood to the alveolus.
So the only solution is assisted ventilation, because the alveoli collapse when they fill with fluid.
Vitamin D is very important since each cell of the body has a vitamin D receptor and this is a transcription factor that expresses about 2000 genes.
Specifically, the cells of the respiratory mucosa have this vitamin D receptor that has the same enzyme as the kidney that transforms vitamin D into its active form.
Vitamin D inhibits pro-inflammatory cytokines and activates a protein that is Cathelian that kills viruses, fungi and bacteria
Vitamin D is necessary for the recovery of respiratory epithelium
It is also necessary for the maturation of immune cells:
- Lymphocytes
- Neutrophils
- Monocytes
- Dendritic cells
All of these immune cells have vitamin D receptors
What is the necessary supplementation?
In my opinion and during the confinement stage, adults should take between 3000-4000 IU/day
Children depend on their size, that is, if an adult can weigh 50-70 kg and if a child weighs 25 kg we would give them 1500 IU/day
So I hope I’ve clarified why vitamin D is so important from an immunological point of view.
And above all, supplementation for the current situation, either because of the time of year (winter) or because we have to stay at home and if we want to improve our immunity and reduce the risk of suffering acute infections, whether bacterial or viral.
Conclusions and bibliographic references
1) Patients who are deficient in vitamin D are more prone to upper respiratory infections
https://www.bmj.com/content/bmj/356/bmj.i6583.full.pdf
2) Patients with vitamin D deficiency may be more likely to suffer from ARDS
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6186338/pdf/APS2018-8494816.pdf
https://thorax.bmj.com/content/thoraxjnl/70/7/617.full.pdf
3) Current Evidence: The Most Critical COVID Patients Suffer from ARDS
https://health.clevelandclinic.org/heres-the-damage-coronavirus-covid-19-can-do-to-your-lungs/
https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
4) Vitamin D reduces inflammation and improves its immune defense response in patients with respiratory diseases and ARDS
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759054/pdf/cei0158-0020.pdf
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3559187/pdf/nihms436898.pdf
