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Vitamin D and Lung Outcomes in Elderly COVID-19 Patients

Take Home Message

In this retrospective cross-sectional study of 65 elderly patients serum, Vitamin D deficiency was associated with more severe lung involvement, longer disease duration, and risk of death in elderly COVID-19 patients.


Sixty-five COVID-19 confirmed patients (mean age 76 years, mean disease duration from first symptom 13±13 days, 54% women) and 65 sex- and age-matched non-COVID control subjects (from the Rheumatology clinic at the same hospital). All COVID-19 patients required hospitalization and were on oxygen therapy for severe respiratory failure, but none needed intensive care treatment or intubation at admission. All study subjects were Caucasian and resided in Genoa, Italy.

Length of Study

All study subjects were enrolled during April and May 2020. COVID-19 patient data generated from hospital admission until discharge or death was evaluated.


  • 25(OH)D serum levels were significantly lower in COVID-19 patients than in controls (median 19.8 vs 40.8 nmol/L). 
  • Among COVID-19 patients, 25(OH)D sufficiency (>75 nmol/L), insufficiency (between 50 and 75 nmol/L), deficiency (between 25 and 50 nmol/L) and severe deficiency (<25 nmol/L) were observed respectively in 11, 11, 21, and 57% of COVID-19 patients. In controls, the same 25(OH)D distribution occurred in 21, 21, 36, and 22% of subjects, respectively. 
  • Lower 25(OH)D serum levels were associated with more severe COVID-19 lung involvement as evaluated by CT imaging: in particular, serum 25(OH)D was significantly lower in COVID-19 patients with either multiple lung consolidations or diffuse/severe interstitial lung involvement (ground glass pattern) than in those with mild lung involvement. 
  • Significantly lower 25(OH)D serum levels were found in the elderly COVID-19 patients who died during hospitalization, compared to those who survived (median 7.5 vs 21 nmol/L). 
  • Significant correlations were observed between low 25(OH)D serum levels and low PaO2 (p = 0.03), SO2 (p = 0.05), and PaO2/FiO2 (p = 0.02), and between low vitamin D serum levels and high levels of the inflammation markers, D-dimer and C-reactive protein. 
  • Lower 25(OH)D serum levels were found associated with longer COVID-19 disease duration. 

Things to Keep in Mind

  • The number of patients analyzed in this study is small and included only elderly patients needing hospitalization and oxygen therapy due to severe respiratory failure, but it did not include either patients with mild disease nor patients needing intensive care treatment or ventilation.  
  • Due to the small number of enrolled patients and large data variability, the sample size was not adequately powered to rule out the variation expected in the main outcome parameters, causing the correlation coefficients to be relatively small.  The study authors suggest conductined robustly designed randomized clinical trials with a larger number of patients to further confirm the preliminary data from this study.
  • COVID-19 patients showed several different comorbidities that might interfere with some results of the study, however, sex- and age-matched healthy subjects had similar comorbidities. 

Author’s Conclusions

Vitamin D deficiency might influence the severity of lung involvement and the risk of deaths in elderly COVID-19 patients hospitalized for COVID-19 infection. 

Study Design

  • Retrospective cross-sectional study 
  • All COVID-19 cases were confirmed by PCR analysis after hospital admission. 
  • Multiple clinical parameters, including comorbidities and laboratory parameters, were collected at admission:  
    • Type of lung involvement assessed by high-resolution CT imaging,
    • Respiratory parameters (partial pressure of oxygen in arterial blood [PaO2], oxygen saturation or percentage of hemoglobin fully combined with oxygen [SO2], partial pressure of carbon dioxide [PaCO2], and the ratio of arterial oxygen partial pressure to fractional inspired oxygen [PaO2/FiO2] measured by arterial blood gas analysis), and 
    • Laboratory parameters (including serum vitamin D [25(OH)D], Ddimer, and C-reactive protein) were assayed by routine standardized assessments in the hospital laboratories. 


Sulli A, Gotelli E, Casabella A, Paolino S, Pizzorni C, Alessandri E, Grosso M, Ferone D, Smith V, Cutolo M. Vitamin D and Lung Outcomes in Elderly COVID-19 Patients. Nutrients. 2021 Feb 24;13(3):717. doi: 10.3390/nu13030717. PMID: 33668240; PMCID: PMC7996150.

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Research Summaries

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19 pandemic: A systematic review

Changes in 25‐hydroxyvitamin D levels post‐vitamin D supplementation in people of Black and Asian ethnicities and its implications during COVID‐19

Vitamin D insufficiency in COVID-19 and influenza A, and critical illness survivors: a cross-sectional study

Take Home Message Vitamin D deficiency/insufficiency was present in majority of hospitalized patients with COVID-19 or influenza A and correlated with severity and persisted in critical illness survivors at concentrations expected