Vitamin D deficiency is frequently reported in patients with SARS-CoV-2 infection. The aim of this study was to correlate serum 25OH-Vitamin D concentrations with clinical parameters of lung involvement, in hospitalized elderly patients with COVID-19.
Sixty-five follow-up COVID-19 patients (mean age 76 ± 13 years) were subsequently examined and compared with sixty-five subjects of age and age control (CNT).
The following clinical parameters were collected: type of lung involvement, respiratory parameters (PaO)2, SO2, PaCO2, PaO2/ FiO2), Laboratory parameters (including 25OH-vitamin D, D-dimer, C-reactive protein), hospital length and COVID-19 signal duration.
Results showed that serum vitamin D levels were significantly lower in COVID-19 patients than in CNT (mean 7.9 vs. 16.3 ng / mL, p = 0.001) and a statistically significant positive correlation was observed between serum levels. vitamin D and PaO2(P = 0.03), SO2(P = 0.05), and PaO2/ FiO2(P = 0.02).
A statistically significant negative correlation was found between serum vitamin D and D-dimer levels (p = 0.04), C-reactive protein (p = 0.04) and percentage of O2In a venturi mask (p = 0.04).
A negative correlation was also observed between serum vitamin D levels and the severity of radiologic lung involvement, assessed by computed tomography: in particular, vitamin D was found to be significantly lower in COVID-19 patients. with either lung multiple consolidation (p = 0.0001) or diffuse / severe interstitial lung involvement than in those with moderate involvement (p = 0.05).
Finally, serum vitamin D levels were found to be significantly lower in the elderly COVID-19 patients who died during hospitalization, compared with those who survived (mean 3.0 vs. 8.4 ng / mL, p = 0.046).
The researchers conclude that this study confirms that serum 25OH-vitamin D deficiency is associated with harder lung involvement, longer disease survival and risk of death, in elderly COVID patients. -19.
Detection of low vitamin D levels also in younger COVID-19 patients with fewer comorbidities suggests that vitamin D deficiency is a critical risk factor at any age.
The report states that the results appear to be related to the role of the biologically active metabolite of vitamin D. [1,25(OH)2-D] that as a steroid hormone is involved in the regulation of growth and differentiation of different types of immune cells.
Some limitations in this study include the small number of patients studied and the variability of big data: for this reason the correlation coefficients are relatively small. Therefore, the need for robustly designed randomized clinical trials involving a greater number of patients.
Research background
This is the latest in a series of studies linking vitamin D deficiency to COVID-19 deficiency. Researchers and health professionals are urging world governments to add vitamin D to their virus-fighting strategies.
Vitamin D has been associated with COVID-19 infection, in terms of higher risk for disease development, higher disease depth, higher frequency of intensive care unit hospitalization, and higher risk of death.
The results of the current study are very similar to the results of a recent study reporting serum vitamin D levels <50 nmol / L (<20 ng / mL) in 61% of hospitalized patients (average age 76 years). They observed a much higher frequency of vitamin D deficiency (<50 nmol / L) in patients requiring intensive care treatment than in those without (81% of patients).
Similarly, another study reported 25OHD deficiency in 67% of patients with moderate SARS-CoV-2 infection, but in 80% of patients requiring mechanical ventilation.
A recent systematic review analyzed seven studies of COVID-19 depth, intensive care treatment, and mortality (1368 patients were admitted) and found an average vitamin D level of 22.9 nmol / L (9.16 ng / mL), higher but similar to that of our group of patients (7.9 ng / mL). Patients with a good prognosis had significantly higher levels of vitamin D compared with those with a poor prognosis.
The low PaO2 / FiO2 ratio was found to be an independent risk factor for death in COVID-19 patients. Our study found a statistically significant positive correlation between serum 25OHD levels and PaO2 / FiO2 values. This observation is consistent with the results of another study reporting the incidence of hypovitaminosis D in COVID-19 patients with a low PaO2 / FiO2 ratio.
The effect of vitamin D on the progression of COVID-19 is not fully understood but this report aims to clarify some pathways.
“1,25 (OH) 2-D plays an antiviral role, regulating the inflammatory response by altering receptor expression similar to NK cell proliferation and function, and eliminating overexpression of cytokines 1,25 (OH) 2-D also strengthens the immune system by stimulating the release of antimicrobial peptide, such as cathelicidin which leads to viral destruction and cleansing and enables the employment of monocytes, macrophages, neutrophils and dendritic cells.
“Thus, 1,25 (OH) 2-D may regulate the textured / altered responses and may inhibit dendritic cell maturation and the ability of antigen expression to T cells, shifting T cell profile from the pro-inflammatory Th1 and Th17 subsets to Th2 and Treg subsets, thereby inhibiting the pro-inflammatory processes.
“In addition to the immunomodulatory and anti-viral effects, 1,25 (OH) 2-D modulates the renin-angiotensin system which also plays an important role in the pathogenesis of COVID-19. e ACE2 is the main host cell receptor that mediates the infection with SARS-CoV-2: the virus binds to ACE2 through its spike glycoprotein to enter the cell, thereby reducing ACE2 expression.
“Vitamin D inhibits renin at the transcription level and consequently angiotensin expression, and increases ACE2 expression, possibly restoring the physiological density of ACE2 reduced by the virus.
“In the lung, several types of alveolar cells express the ACE2 receptor. These cells play an important role in surfactant production, able to regulate alveolar surface tension. SARS-CoV-2 can activate the cells alveolar uptake by binding ACE2 and suppression of surfactant production.Resorption of alveolar cells leads to lung damage and respiratory failure due to loss of lung surfactant.This damage may be prevented by vitamin D.
“Interestingly … vitamin D deficiency is associated with an increased risk of thrombotic events. As is well known, patients with COVID-19 often suffer from microthrombotic complications, which can contribute to infection. worsening lung and death. The main results of autopsy histops report its persistent alveolar damage, mainly characterized by focal capillary microthrombosis. “
Source: Nutritionists
Cutolo. M., et al
“Vitamin D and lung outcomes in elderly COVID-19 patients”
https://doi.org/10.3390/nu13030717