25 Hydroxyvitamin D Serum Concentration and COVID-19 Severity and Outcome-A Retrospective Survey in a Romanian Hospital

Nutrients. 2023 Feb 28;15(5):1227. doi: 10.3390/nu15051227.


Interest in the immunomodulatory function of vitamin D has grown since the COVID-19 pandemic started. Our study investigated the possible association between vitamin D deficiency and COVID-19 severity, intensive care needs, and mortality in patients hospitalized with COVID-19. A prospective cohort study was performed on 2342 COVID-19 hospitalized patients between April 2020 and May 2022 in a Romanian tertiary hospital for infectious diseases. A multivariate generalized linear model for binary data was fit with dependent variables: severe/critical form of COVID-19, intensive care need, and fatal outcome as a function of vitamin D deficiency, controlling for age, comorbidities, and vaccination status. More than half of the patients (50.9%) were classified with vitamin D deficiency based on a serum concentration of less than 20 ng/mL. There was a negative association between vitamin D and age. Vitamin D-deficient patients presented with more cardiovascular, neurological, and pulmonary diseases, as well as diabetes, and cancer. In multivariate logistic regression models, vitamin D-deficient patients had higher odds of severe/critical forms of COVID-19 [OR = 1.23 (95% CI 1.03-1.47), p = 0.023] and higher odds of death [OR = 1.49 (95% CI 1.06-2.08), p = 0.02]. Vitamin D deficiency was associated with disease severity and death outcome in hospitalized COVID-19 patients.

Keywords: 25(OH)D deficiency; COVID-19; ICU need; comorbidities; mortality; severity form; vitamin D deficiency.

MeSH terms

  • COVID-19* / complications
  • Calcifediol
  • Hospitals
  • Humans
  • Pandemics
  • Prospective Studies
  • Retrospective Studies
  • Romania
  • Vitamin D
  • Vitamin D Deficiency*
  • Vitamins


  • Vitamin D
  • Calcifediol
  • Vitamins

Grant support

This work was granted by project PDI-PFE-CDI 2021, entitled Increasing the Performance of Scientific Research, Supporting Excellence in Medical Research and Innovation, PROGRES, no. 40PFE/30.12.2021.