Advances in the medical treatment of severe forms of COVID-19 mean that the death rate associated with this disease has dropped significantly since the start of the pandemic.
• Read also: New proof of the benefits of vitamin D
• Read also: Vitamin D to prevent serious complications from COVID-19
These include drugs such as dexamethasone, which helps counter the devastation caused by excessive inflammation generated in response to the virus, or anticoagulants, which prevent the formation of blood clots that compromise the function of vital organs such as the lungs. , heart and kidneys.
Vitamin D deficiency
Despite these successes, it is obviously best to prevent complications from COVID-19 at the source, before they lead to too much deterioration in the condition of the infected person.
One very promising avenue to achieve this seems to be relying on high blood levels of vitamin D.
Clinical studies have indeed shown that vitamin D deficiency is associated with an increased risk of developing serious complications from COVID-19 and dying from the disease.
For example, an Italian study recently reported that in patients very ill with COVID-19, below normal blood levels of vitamin D (10 ng / mL) were associated with a ten-fold higher risk of death than in those with normal levels (30 ng / mL)(1).
Another study has just confirmed this astonishing association (2).
By analyzing the medical records of 235 patients with COVID-19, the researchers observed that those with normal vitamin D blood levels had 6 times less risk of unconsciousness, 2 times less risk of hypoxia ( insufficient oxygen in the blood) and 50% less risk of death.
So while 20% of vitamin D deficient patients died of the disease, this proportion dropped to 9.7% in those with normal levels and decreased to 6.7% in those with high vitamin D levels. (more than 40 ng / mL).
These protective effects of vitamin D are consistent with the many known roles of this vitamin in immune function.
Several genes involved in immunity are influenced by vitamin D, especially in killer T lymphocytes which specialize in killing cells infected with a virus.
Vitamin D also acts as a conductor of the inflammatory response, allowing immune cells to fight infection while preventing the development of excessive inflammation that can run away and attack vital organs.
The importance of vitamin D in preventing complications from COVID-19 may also explain why some people are more vulnerable to the disease.
We know, for example, that vitamin D deficiency is more common in obese people and this deficiency could contribute to the highest mortality rate affecting this population.
It is also very common for black people to be deficient in vitamin D (the high amount of eumelanin in their skin reduces the production of vitamin D by UV rays from the sun), which could explain why this population has been very heavily affected by COVID-19, both in terms of the number of cases and the death rate.
In the United States, it is estimated that one in a thousand African-Americans has died from the disease since the start of the pandemic, a proportion that may even increase in the coming months if rates of transmission of the virus continue. to be raised.
These observations must be taken into account, since the current increase in transmission of the coronavirus responsible for COVID-19 coincides with the time of year when the sunshine is at its lowest and the risk of vitamin D deficiency is the highest, in the Nordic countries.
Daily intake of supplements containing 1000 IU of vitamin D is an effective and inexpensive way to avoid these deficiencies and at the same time prevent the risk of complications associated with COVID-19, which the authors of this study recommend.
(1) Carpagnano GE et al. Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19. Journal of Endocrinological Investigation, August 9, 2020.
(2) Maghbooli Z et al. Vitamin D sufficiency, a serum 25-hydroxyvitamin D at least 30 ng / mL, reduced risk for adverse clinical outcomes in patients with COVID-19 infection. PloS One, September 25, 2020.