High Dose Vitamin-D Substitution in Patients With COVID-19: a Randomized Controlled, Multi Center Study

The world is currently experiencing a coronavirus (SARS-CoV-2) pandemic. The disease caused by infection with this virus is known as COVID-19. Risk factors for a poor outcome of COVID-19 have so far been found to include, older age and co-morbidity including chronic respiratory conditions and current smoking status. Previous studies found, that vitamin D deficiency is more prevalent among patients with these risk factors.

There are observational studies reporting independent associations between low serum concentrations of 25-hydroxyvitamin D (the major circulating vitamin D metabolite) and susceptibility to acute respiratory tract infection. 25-hydroxyvitamin D supports induction of antimicrobial peptides in response to both viral and bacterial stimuli suggesting a potential mechanism by which vitamin D inducible protection against respiratory pathogens might be mediated. The clear functions of vitamin D in the immune system are difficult to define because the immune response is not a static process. The vitamin-D-receptor, which has also been detected in immunological cells, suggests that vitamin D can regulate some processes related to immunity. A further argument which supports a potential antiviral activity of vitamin D is the modulation of the inflammatory response. The release of pro-inflammatory cytokines by the influenza virus appeared to correlate with the severity of illness. The use of vitamin D as a prophylactic for influenza has shown promise in prevention of illness and reduction of secondary asthma in children. Inadequate vitamin D status is associated with susceptibility to upper respiratory infections in patients with chronic obstructive pulmonary disease (COPD). In the ViDiCo-trial vitamin D supplementation protected against moderate or severe exacerbation, but not upper respiratory infection, in patients with COPD. A further study retrospectively examined data from 108 patients with acute respiratory distress syndrome (ARDS) for whom a vitamin D status was available at the time of diagnosis revealed that over 95% of these patients had vitamin D deficiency. When examined according to quarterly of serum 25- hydroxyvitamin D, a consistent inverse relationship between serum 25-hydroxyvitamin D and length of hospital and ICU stay among survivors was observed. Vitamin D substitution in patients with COVID-19 who show a vitamin D deficiency should therefore be investigated for efficacy and safety.

For this purpose the investigators designed a randomized, placebo controlled double blind trial to test the hypothesis hypothesis that a single high dose of vitamin D in addition to standard treatment improves the recovery period positively in patients with COVID-19 and vitamin D deficiency compared to standard treatment only. That means, that the time of recovery is shorter in the single high dose vitamin D group relative to standard treatment group only.