Circulating Vitamin D levels status and clinical prognostic indices in COVID-19 patients

Respir Res. 2021 Mar 3;22(1):76. doi: 10.1186/s12931-021-01666-3.


Background: Several immune mechanisms activate in COVID-19 pathogenesis. Usually, coronavirus infection is characterized by dysregulated host immune responses, interleukine-6 increase, hyper-activation of cytotoxic CD8 T lymphocytes. Interestingly, Vitamin D deficiency has been often associated with altered immune responses and infections. In the present study, we evaluated Vitamin D plasma levels in patients affected with different lung involvement during COVID-19 infection.

Methods: Lymphocyte phenotypes were assessed by flow cytometry. Thoracic CT scan involvement was obtained by an image analysis program.

Results: Vitamin D levels were deficient in (80%) of patients, insufficient in (6.5%) and normal in (13.5%). Patients with very low Vitamin D plasma levels had more elevated D-Dimer values, a more elevated B lymphocyte cell count, a reduction of CD8 + T lymphocytes with a low CD4/CD8 ratio, more compromised clinical findings (measured by LIPI and SOFA scores) and thoracic CT scan involvement.

Conclusions: Vitamin D deficiency is associated with compromised inflammatory responses and higher pulmonary involvement in COVID-19 affected patients. Vitamin D assessment, during COVID-19 infection, could be a useful analysis for possible therapeutic interventions.

Trial registration: 'retrospectively registered'.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • CD8-Positive T-Lymphocytes / metabolism
  • COVID-19 / blood*
  • COVID-19 / diagnostic imaging
  • COVID-19 / epidemiology*
  • Female
  • Humans
  • Italy / epidemiology
  • Lung / diagnostic imaging
  • Male
  • Middle Aged
  • Prognosis
  • Vitamin D / blood*
  • Vitamin D Deficiency / blood*
  • Vitamin D Deficiency / diagnostic imaging
  • Vitamin D Deficiency / epidemiology*


  • Vitamin D