Introduction Increased age has been reported to be a factor for COVID-19 severe outcomes.
However, many studies do not consider the age dependency of comorbidities, which …

There is still limited evidence regarding the influence of vitamin D in people with COVID-19.
In this systematic review and meta-analysis, we analyze the association between vitamin D …

Background COVID-19 vaccines show excellent efficacy in clinical trials and effectiveness in
real-world data, but some people still become infected with SARS-CoV-2 after vaccination …

Background Obesity is a major risk factor for adverse outcomes after infection with SARS-
CoV-2. We aimed to examine this association, including interactions with demographic and …

Background. The objective of this quasi-experimental study was to determine whether bolus
vitamin D supplementation taken either regularly over the preceding year or after the …

Background Previous studies suggested that the prevalence of chronic respiratory disease
in patients hospitalised with COVID-19 was lower than its prevalence in the general …

Abstract Background Coronavirus disease (COVID–19) has resulted in the death of more
than 3.5 million people worldwide. While COVID–19 mostly affects the lungs, different …

The clinical course and outcome of COVID-19 are highly variable, ranging from
asymptomatic infections to severe disease and death. Understanding the risk factors of …

Background This study applies an umbrella review approach to summarise the global
evidence on the risk of severe COVID-19 outcomes in patients with pre-existing health …

The COVID-19 pandemic has disproportionately affected certain groups, such as older
people (ie,> 65 years), minority ethnic populations, and people with specific chronic …