Vitamin D Levels Are Associated With Blood Glucose and BMI in COVID-19 Patients, Predicting Disease Severity

J Clin Endocrinol Metab. 2022 Jan 1;107(1):e348-e360. doi: 10.1210/clinem/dgab599.

Abstract

Context: A high prevalence of vitamin D (VD) deficiency in COVID-19 patients has been reported and hypothesized to increase COVID-19 severity likely because of its negative impact on immune and inflammatory responses. Furthermore, clear associations between hypovitaminosis D and fat body mass excess and diabetes, factors associated with COVID-19 severity, have been widely recognized.

Objective: The aim of this study was to evaluate in COVID-19 patients the relationship between VD levels and inflammatory response, body mass index (BMI), blood glucose (GLU), and disease severity.

Methods: Patients admitted to San Raffaele-Hospital for COVID-19 were enrolled in this study, excluding those with comorbidities and therapies influencing VD metabolism. 25-Hydroxyvitamin D levels, plasma GLU levels, BMI, and inflammatory parameters were evaluated at admission.

Results: A total of 88 patients were included. Median VD level was 16.3 ng/mL and VD deficiency was found in 68.2% of patients. VD deficiency was found more frequently in male patients and in those affected by severe COVID-19. Regression analyses showed a positive correlation between VD and PaO2/FiO2 ratio, and negative correlations between VD and plasma GLU, BMI, neutrophil/lymphocyte ratio, C-reactive protein, and interleukin 6. Patients with both hypovitaminosis D and diabetes mellitus, as well those with hypovitaminosis D and overweight, were more frequently affected by a severe disease with worse inflammatory response and respiratory parameters, compared to those without or just one of these conditions.

Conclusion: We showed, for the first-time, a strict association of VD levels with blood GLU and BMI in COVID-19 patients. VD deficiency might be a novel common pathophysiological mechanism involved in the detrimental effect of hyperglycemia and adiposity on disease severity.

Keywords: COVID-19; SARS-CoV-2; body mass index; plasma glucose; vitamin D.

MeSH terms

  • Adiposity / immunology*
  • Aged
  • Biomarkers / blood
  • Blood Glucose / analysis
  • Body Mass Index
  • COVID-19 / blood
  • COVID-19 / diagnosis*
  • COVID-19 / immunology
  • COVID-19 / virology
  • Female
  • Humans
  • Hyperglycemia / blood
  • Hyperglycemia / diagnosis
  • Hyperglycemia / epidemiology*
  • Hyperglycemia / immunology
  • Male
  • Middle Aged
  • Retrospective Studies
  • Risk Factors
  • SARS-CoV-2 / immunology
  • SARS-CoV-2 / isolation & purification
  • Severity of Illness Index
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / diagnosis
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / immunology

Substances

  • Biomarkers
  • Blood Glucose
  • Vitamin D
  • 25-hydroxyvitamin D