MECHANISMS IN ENDOCRINOLOGY: Vitamin D and COVID-19

Abstract

The SARS-CoV-2 virus responsible for the COVID-19 pandemic has generated an explosion of interest both in the mechanisms of infection leading to dissemination and expression of this disease, and in potential risk factors that may have a mechanistic basis for disease propagation or control. Vitamin D has emerged as a factor that may be involved in these two areas. The focus of this article is to apply our current understanding of vitamin D as a facilitator of immunocompetence both with regard to innate and adaptive immunity and to consider how this may relate to COVID-19 disease. There are also intriguing potential links to vitamin D as a factor in the cytokine storm that portends some of the most serious consequences of SARS-CoV-2 infection such as the acute respiratory distress syndrome. Moreover, cardiac and coagulopathic features of COVID-19 disease deserve attention as they may also be related to vitamin D. Finally, we review the current clinical data associating vitamin D with SARS-CoV-2 infection, a putative clinical link that at this time must still be considered hypothetical.

Are women with osteoporosis treated with denosumab at risk of severe COVID-19?

“…Interestingly, all the patients were taking vitamin D as part of their antiosteoporotic treatment as recommended by guidelines [20]. Since vitamin D may have immune stimulating actions and can protect against respiratory infections [21], it has been previously suggested that widespread hypovitaminosis D may predispose to COVID-19 [22], and vitamin D treatment may have beneficial effects in the pandemic [23]. Therefore, it can be hypothesized that our patients with osteoporosis may be protected from SARS-COV2 by vitamin D independently of the pharmacologic antiosteoporotic treatments.…”

Role of vitamin D in diabetic retinopathy: Pathophysiological and clinical aspects

“…The above reviewed clinical and pathophysiological aspects suggest that VD deficiency may be implicated in the development and progression of DR. Since hypovitaminosis D is widespread and heavily impacts in the whole world [13], and is related also to development and natural history of T2DM, it can be suggested to determine the levels of VD in DR patients. Moreover, it can be suggested to integrate VD with cholecalciferol in patients with DR and severe VD deficiency, as well as in the general population [148].…”

“…Assessment of total 25OHVD is widely accepted as a marker of the VD status [2,12] and is used by several agencies to support vitamin D dietary requirements and thresholds for hypovitaminosis D in population surveillance [2,13,14]. In fact, definition of VD deficiency is still an open issue, as apparent from different recommendations from various scientific bodies [15].…”

Is there a link between vitamin D status, SARS‐CoV‐2 infection risk and COVID‐19 severity?

“…Vitamin D‐mediated induction of cathelicidin and defensins also impair viral replication 117,118 and enhancement of autophagy in APC, which is involved in antigen presenting, also helps in clearing up viruses 119,120 . The importance of vitamin D‐stimulated autophagy has been demonstrated in human immunodeficiency virus (HIV), influenza A, rotavirus and human C hepatitis virus (HCV) infections, as reviewed in Reference 121.…”