In addition, the percentage of deaths were found to be significantly in those who did not receive the 25OHD supplement.
This followed the finding that 87% of the Italian cohort studied were deficient in 24OHD, which was found to be associated with an increased severity of respiratory distress.
The clear association between poor status and worsened outcomes in Covid patients was recently highlighted by Professor Philip Calder from the University of Southampton, yet he had specified "whether it can be used to improve outcome in those already hospitalised with COVID-19 is uncertain".
The ‘Nutrients’ report builds on this critical question as well as the ever-growing body of evidence on the efficacies of nutritional supplements for Covid-19 published over the recent months.
The Italian researchers explained: “Low levels of 25OHD were associated with increased levels of serum markers of inflammation, which in turn seemed to have a negative predictive role regarding the course of this infectious disease.”
“The finding of low levels of 25OHD in patients with severe COVID-19 could at least be considered as a prognostic marker, thus also confirming the immunoprotective role of vitamin D and its preventive role in COVID-19 infection when administered as a supplement,” the researchers stress.
Vitamin D for disease
COVID-19 is a highly contagious syndrome caused by the SARS-CoV-2 pathogen, which caused a largely prevalent pandemic beginning in 2019. With subsequent symptoms ranging from moderate to severe, it has been reported that certain factors may worsen the prognosis, such as age, cardiovascular diseases, obesity, diabetes, and lung diseases.
Despite recent advancements in understanding of the pathogenesis of Covid, available therapies have shown variable efficacies. This has led to a heightened interest in natural alternative treatment options.
Studies investigating the association between vitamin D status and COVID-19 occurrence have increased exponentially, with deficiencies being linked to an increased risk of infection. It is known that vitamin D plays a critical immunomodulant role, with macrophages and monocytes noted to have the vitamin D receptor for its conversion.
Previous research has reported the potential benefits of vitamin D supplementation with regards to reducing the risk of developing complications. Thus, the present study sought to continue this work, investigating the role of vitamin D status and supplementation in the prognosis and mortality in hospitalised COVID-19 patients.
The study included 288 hospitalised patients from two hospitals in Italy during 2020-2021. Calciferol (25OHD) levels were measured, whilst those with levels below 20 ng/mL were supplemented with 450 micrograms of 25OHD for two consecutive days. Various laboratory investigations were conducted and scans including ECG and chest ultrasounds were conducted.
A significant 25OHD deficiency prevalence was identified from the included cohort, with 87% of patients proving to have levels below 30 ng/mL. These deficiencies were reported to be associated with a longer duration of hospitalisation in these patients.
Supplementation with 25OHD in these deficient patients significantly reduced the duration of hospitalisation, whilst the percentage of deaths were significantly higher in those who did not receive the supplement.
In addition, it was found that the 25OHD levels were positively correlated with the partial pressure of oxygen and FiO2 (PaO2/FiO2) ratio; a relationship closely associated with the degree of severity of respiratory distress.
Regarding the findings, the researchers explain: “In the overall sample, circulating levels of 25OHD were inversely correlated with increasing serum levels of inflammation markers (CRP, D-dimer, fibrinogen), reaching statistical significance for LDH.
“Interestingly, low vitamin D status has previously been shown to be associated with an enhanced acute inflammatory reaction which becomes particularly relevant when 25OHD levels are below 20 ng/mL,” they add.
The report concludes that the study provides significant evidence to suggest that adequate vitamin D levels and treatment with calcifediol supplementation would be the best prognosis for COVID-19 patients.
Yet, they highlight the low levels of control and the small samples utilised in the study, and urge further RCTs to confirm these associations.
“Vitamin D Deficiency in COVID-19 Patients and Role of Calcifediol Supplementation”
by Christian Mingiano, Tommaso Picchioni, Guido Cavati, Filippo Pirrotta, Marco Calabrese, Ranuccio Nuti, Stefano Gonnelli, Alberto Fortini, Bruno Frediani, Luigi Gennari and Daniela Merlotti