Importance of vitamin D levels in COVID-19 infection

Okuturlar Y. , Çelik Ö. , Köksal I.

31. ECCMID, 9 - 12 July 2021, pp.2052

  • Publication Type: Conference Paper / Summary Text
  • Page Numbers: pp.2052


Importance of vitamin D levels in COVID-19 infection

Pandemic coronavirus disease (Covid-19) is currently the leading cause of death worldwide. To date, no spesific medicine has been found for the definitive treatment of this disease or a vaccine to prevent it. Vaccination, masks and social distancing are the only ways to prevent the spread of this disease to society. Vitamin D is an important micronutrient and has been reported to protect against respiratory diseases by improving immunity.


In this study, we aimed to reveal whether the 25-hydroxyvitamin D (25 (OH) D) concentration is associated with the risk and severity of Covid-19 by evaluating vitamin Dlevels in outpatients or hospitalized patients with the diagnosis of Covid-19. 


In the study, the test results of 124 cases whose vitamin D levels were measured between March 11, 2020 and May 31, 2020 were analyzed retrospectively. 

Covid-19 RT-PCR results in nose and throat swab samples, clinical course and laboratory findings of the patients were retrospectively analyzed.

Statistical analysis was done using IBM SPSS 23. Kolmogorov Smirnov, Man Whitney U, Kruskal Wallis Test, Chi square and fisher extract and risk analysis tests were used.

Categorical variables were expressed as%. P value <0.05 was considered significant.


Of the 2800 patients who were included in the study and had the Covid-19 RT-PCR test from the nose and throat swab, 33.9% of 124 patients whose 25 (OH) vitamin D levels were measured, RT-PCR test was found to be positive. 

25 (OH) D vitamin levels of these patients are shown in Table 1 according to their clinical characteristics.

Vitamin 25 (OH) D level in 32 patients (median 10.2) who were given antiviral favipiravir treatment because of their need for oxygen. It was found to be significantly lower than the other 92 patients (median 16.25).

When patients who needed O₂ treatment during Covid 19 treatment were examined in terms of vitamin D levels; It was observed that patients with 25 (OH) vitamin D level <10 needed more O₂ and these patients started favipiravir treatment (OR: 2,833 CI 95% 1,230-6,528, p = 0.013).

In patients with 25 (OH) vitamin D <10, more patients had pulmonary involvement with Thorax CT (OR: 2.225 CI 95% 0.999-4.952 p = 0.048). It was observed that patients with 25 (OH) vitamin D <10 had more back pain symptoms (OR: 4,765 CI 95% 1,126-20,163 p = 0.022). Patients with 25 (OH) vitamin D <10 had a greater number of decreased sense of smell and taste (OR: 11,857 CI 95% 1,336-105,214 p = 0.006).

In addition, 25 (OH) vitamin D levels were positively correlated with aPTT, while it was negatively correlated with neutrophil / monocyte ratio, glucose, ALT, AST, GGT, and LDH (Table 2).


Our findings suggest a potential link between vitamin D concentrations  and prognosis of Covid-19 infection. 

The low level of 25 (OH) vitamin D especially in patients with thorax CT involvement and in whom favipiravir treatment was initiated reveals the importance of vitamin D supplementation.