Bad Prognosis in Critical Ill Patients with COVID‐19 during Short‐Term ICU Stay Regarding Vitamin D Levels

Background and aims: Vitamin D inadequacy may be involved in the mechanisms of SARS‐CoV‐2 infection and in potential risk factors for disease propagation or control of coronavirus disease 2019 (COVID‐19). This study assessed a short‐term evolution of vitamin D status and its influence upon different clinical parameters in critically ill patients with COVID‐19. Methods: A prospective analytical study in which 37 critically ill volunteers between 41 and 71 years of age with COVID‐19 were evaluated at baseline and three days of intensive care unit (ICU) stay. 25‐OH‐D3 and 25‐OH‐D2 were analyzed by liquid chromatography–tandem mass spectrometry and total 25‐ OH‐D levels were calculated as the sum of both. Results: All patients presented low 25‐OH‐D levels at baseline, decreasing total 25‐OH‐D (p = 0.011) mainly through 25‐OH‐D2 (p = 0.006) levels during ICU stay. 25‐OH‐D2 levels decreased a mean of 41.6% ± 89.6% versus 7.0% ± 23.4% for the 25‐OH‐ D3 form during the ICU stay. Patients who did not need invasive mechanical ventilation presented higher levels of 25‐OH‐D2 at baseline and follow‐up. Lower 25‐OH‐D and 25‐OH‐D3 levels were associated with higher D‐dimer at baseline (p = 0.003; p = 0.001) and at follow up (p = 0.029), higher procalcitonin levels (p = 0.002; p = 0.018) at follow up, and lower percentage lymphocyte counts (p = 0.044; p = 0.040) during ICU stay. Conclusions: Deficient vitamin D status in critical patients was established at the admission and further worsened after three days of stay. Lower vitamin D levels were related to key altered clinical and biochemical parameters on patients with SARS‐CoV‐2 infec‐ tion. Given the different response of the 25‐OH‐D3 and 25‐OH‐D2 forms, it would be useful to mon‐ itor them on the evolution of the critically ill patient.FIS Projects from Carlos III Health Institute [REF. PI10/1993]Spanish Ministry of Educatio