The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the cause of the 2019 coronavirus disease (COVID-19) pandemic, continues to spread worldwide.
With tremendous research, the world scientific community continues to try to identify the causes of large variations in the manifestations and severity of the disease.
New study published in the journal Endocrine in January 2021 shows that low vitamin D levels are associated with an increased risk of COVID-19 hospitalization.
If this is confirmed, vitamin D supplementation can be a cheap and quick way to ensure better results in such patients.
Risk factors for severe COVID-19
Of the 97 million confirmed cases on Earth, more than 2 million people have died. The unusual nature of this virus is that it causes serious or even critical illness in a significant minority of patients, while the majority escape without mild or moderate symptoms.
So far, researchers have found that men are at higher risk for adverse consequences, as are those with diabetes mellitus, obesity, and hypertension. Vitamin D deficiency has recently been hypothesized to be a factor associated with an increased risk of poor prognosis for COVID-19.
Mechanism of vitamin D in the immune response
This association is biologically plausible because vitamin D modulates both innate and adaptive immunity, and individuals with low vitamin D levels are known to be more susceptible to infections caused by bacteria or viruses.
Very early in the pandemic, many reports linked countries with lower average vitamin D levels to mortality. And finally, patients who are hospitalized on this farm have been shown to have very low levels of 25-hydroxyvitamin D, providing direct evidence of this association.
This study was conducted in Armenia, which has a high ethnic and cultural diversity among a population of 3 million. To date, the country has reported 165,528 cases and 3,021 COVID-19 cases.
The researchers measured 25-hydroxyvitamin D levels in patients at a designated COVID-19 hospital in Yerevan, Armenia. They compared these measurements with healthy population control measures in the same country.
The study period was five weeks and included blood samples measured for 25-hydroxyvitamin D from 330 consecutive patients admitted with COVID-19. The researchers also received data on other variables that may confuse outcomes such as age, gender, height, weight, occupation, pre-existing conditions, active tuberculosis, smoking status, supplemental oxygen use, intubation status, and duration of hospitalization for discharge or death.
Lower vitamin D levels in hospitalized COVID-19 patients
The researchers found that the most common comorbid conditions in this group of patients were hypertension, diabetes, smoking-related complications, and lung disease. Patients were hospitalized for an average of 11 days, and more than half of them underwent supplemental oxygen therapy. Only about 5 percent required intubation, and 24 deaths occurred.
The mean 25-hydroxyvitamin D concentration was about 13 ng / ml, but less than 12 ng / ml in about 45% of them. This is generally accepted to show honest vitamin D deficiency. In contrast, the average vitamin D level in Armenian women was about 20 ng / ml.
The researchers found that older patients and patients with higher BMI had a longer hospital stay. However, both of these categories, as well as other chronic diseases, require longer supplemental oxygen. When other confounding factors were compensated, age and length of hospital stay were found to be significant risk factors for death after COVID-19, as well as other important variables.
However, 25-hydroxyvitamin D levels were not significantly associated with BMI, residence time, oxygen supplementation, or death. Mean vitamin D levels in the affected patients were not much lower than in the survivors, although they decreased slightly.
What are the consequences?
Nearly half of the hospitalized patients had levels below 12 ng / ml, indicating a clear deficiency. This shows a striking association, as only 13% of the national population had a similarly low level. Comparison of results, BMI, and age showed no difference between patients with low vitamin D levels, either below or above 12 ng / ml.
The low indication of vitamin D in hospitalized patients indicates that this deficiency can severely affect the host immune response in terms of adaptive immunity.
It is important to conduct prospective studies to determine whether vitamin D intervention can be protective against COVID-19, and whether the use of vitamin D can reduce its severity, ”the researchers conclude.