Demir M, Demir F, Aygun H. Vitamin D deficiency is associated with COVID-19 positivity and the severity of the disease. J Med Virol. 2021 Jan 29. doi: 10.1002/jmv.26832. Epub ahead of print. PMID: 33512007.

Objective: The present study examined the relationship between PCR test positivity and clinical outcomes of vitamin D levels measured within the six months before the PCR test in COVID-19 positive patients.

Materials and methods: In this retrospective cohort study,COVID-19(227) and non-COVID-19 patients(260) were divided into four groups according to their vitamin D levels: Group I (0-10 ng/ml), Group II (10-20 ng/ml),Group III (20-30 ng/ml),and Group IV(Vitamin D>30ng/ml).Laboratory test results and the radiological findings were evaluated. In addition,for comparative purposes,medical records of 1200 patients who had hospital visit in 1 November 2019-1 November 2020 period for complaints due to reasons not related to COVID-19 were investigated for the availability of vitamin D measurements.This search yielded 260 patients with tested vitamin D levels.

Results: Vitamin D levels were below 30 ng/ml in 94.27% of 227 COVID-19 positive patients [average age:46.32±1.24 years (range:20-80years) and 56.54% women] while 93.07% of 260 non-COVID-19 patients [average age:44.63±1.30 years (range:18-75years) and 59.50% women] had vitamin D levels below 30 ng/ml.Nevertheless,very severe vitamin D deficiency (<10 ng/ml) was considerably more common in COVID-19 patients (44%) [average age:44.15±1.89 years (range:23-80years) and 57.57% women] than in non-COVID-19 ones (31%) [average age:46.50±2.21 years (range:20-75) and 62.5% women].Among COVID-19 positive patients,the group with vitamin D levels of >30 ng/ml had significantly lower D-dimer and CRP levels,number of affected lung segments and shorter hospital stays.No difference was found among the groups in terms of age and gender distribution.

Conclusion: Elevated vitamin D levels could decrease COVID-19 PCR positivity,D-dimer and CRP levels and the number of affected lung segments in COVID-19 positive patients,thereby shortening duration of hospital stays and alleviating the intensity of COVID-19.