Before the COVID-19 pandemic started Vitamin D was discussed as a preventative strategy
in acute respiratory tract infections. There is a growing evidence of beneficial effects
of vitamin D supplementation in COVID-19 patients.
The term post-COVID-19 syndrome (PCS) describes new, returning or ongoing symptoms
more than 12 weeks after COVID-19 infection which cannot be explained by any other
disorders or illnesses. The most common symptoms of PCS includes fatigue, difficulty
breathing, memory/concentration/sleep problems persistent cough, muscle aches, depression,
and others.
We conducted a retrospective analysis of vitamin D level in a PCS cohort without hospitalisation.
Taking of blood samples was part of the routine assessment in PCS consultation hours.
We found significant lower vitamin D levels in the PCS cohort compared to a non-COVID
control group. Within the non-COVID cohort there were no differences regarding vitamin
D levels.
Our results recorded for the first-time decreased vitamin D values in a PCS cohort
compared to a control group. There are several potential reasons for these observations.
The decrease could be the consequence of overcoming the infection by consumption of
vitamin D. The reduction could also be the consequence of a longer duration of illness
without exposure to sunlight or malnutrition. Similarly, reduced outdoor exercise
during the pandemic with its restriction could have influenced vitamin D levels. Finally,
reduced physical activity because of ongoing PCS symptoms like fatigue or exercise
intolerance might be a possible explanation for the drop in vitamin D levels.
Now a randomized controlled trial is necessary to clarify the effects of vitamin D
supplementation in PCS subjects.
