key: cord-0688118-fdawfdnt
authors: Speeckaert, Marijn M.; Speeckaert, Reinhart; Delanghe, Joris R.
title: Vitamin D sufficiency and COVID-19: is vitamin D binding protein (and its polymorphism) the missing link?
date: 2021-04-02
journal: Endocr Pract
DOI: 10.1016/j.eprac.2021.03.011
sha: c52e94fe0b05d4dd05ad7ab5351bc80e1c86985e
doc_id: 688118
cord_uid: fdawfdnt

nan

To the editor, With interest, we read with interest the paper of Charoenngam et al. (1) , which revealed an independent association between vitamin D sufficiency and decreased risk of mortality from Coronavirus disease 2019 in elderly patients and patients without obesity.

Besides the investigated comorbidities, we would like to highlight the potential influence of vitamin D binding protein (DBP) and its polymorphism on the reported results. DBP showed a similar concentration gradient among these phenotypes (2) . In a previous study of our group, the DBP1 allele frequency was associated with a lower prevalence and mortality due to a SARS CoV 2 infection.

Although a favorable prognosis is observed in most COVID-19 patients, SARS-CoV-2 infection can lead to pneumonia, severe hypoxemia, and acute respiratory distress syndrome (ARDS). In ARDS patients, vitamin D deficiency is ubiquitous, and significantly higher vitamin D levels have been found in survivors in comparison with non-survivors. A 30% reduction of DBP in patients with ARDS supports a role for either reduced production or increased losses as a partial explanation of vitamin D deficiency (3).

Several potential hypotheses could explain the findings above. First of all, as mentioned by In conclusion, DBP and its polymorphism should be taken into account in future studies investigating the association between vitamin D and COVID-19.

Association of vitamin D status with hospital morbidity and mortality in adult hospitalized COVID-19 patients

Biological and clinical aspects of the