Serum vitamin D levels and inflammatory status in COVID-19 patients.

Objectives: The coronavirus 2019 disease (COVID-19) is characterized by a heterogeneous clinical presentation, a complex pathophysiology and a wide range of laboratory findings, depending on disease severity.

Background: We studied some laboratory parameters in correlation with vitamin D status representing the inflammatory state in hospitalized COVID-19 patients on admission.

Methods: The study included 100 COVID-19 patients with moderate (n=55) and severe (n=45) form of the disease. Complete blood count and differential blood count, routine biochemical parameters, C-reactive protein and serum procalcitonin, ferritin, human IL-6 and serum vitamin D (measured as 25-OH vitamin D) concentrations, were performed.

Results: According to the severity of the disease, patients with severe form had significantly lower serum vitamin D (16.54±6.51 ng/ml vs 20.37±5.63 ng/ml, p=0.0012), higher serum interleukin-6 (41.24±28.46 pg/ml vs. 24.75±16.28 pg/ml, p=0.0003), C-reactive protein (101.49± 57.15 mg/l vs 74.43±42.99 mg/l, p=0.0044), ferritin (969.89±338.37 ng/ml vs 845.96±359.91 ng/ml, p=0.0423) and LDH (1050.53±369.11 U/l vs 905.31±335.57 U/l, p=0.0222) compared to those with moderate form of the disease.

Conclusion: The presented data provide a relationship between increased inflammatory laboratory markers, low vitamin D levels and disease severity in COVID-19 patients (Tab. 2, Fig. 3, Ref. 32).