Vitamin D and SARS-CoV-2 Infection: SERVE Study (SARS-CoV-2 Exposure and the Role of Vitamin D among Hospital Employees)

Exploring the Preventive Potential of Vitamin D against Respiratory Infections in Preschool-Age Children: A Cross-Sectional Study

Recent studies hypothesized that vitamin D supplementation and subsequent higher 25(OH)D serum levels could protect against respiratory infections in children. This cross-sectional study, conducted from May 2022 to December 2023 in Timisoara, Romania, aimed to evaluate the potential influence of vitamin D supplementation on the incidence of respiratory infections among preschool-age children. This study examined 215 children over 18 months who were split into a group of patients with recurrent respiratory infections (n = 141) and another group of patients with only one respiratory tract infection in the past 12 months (n = 74). Patients were evaluated based on their serum vitamin D levels 25(OH)D, demographic characteristics, and health outcomes. The study identified that preschool-age children with recurrent infections had significantly lower mean vitamin D concentrations (24.5 ng/mL) compared to the control group (29.7 ng/mL, p < 0.001). Additionally, a higher proportion of vitamin D deficiency was observed among children with recurrent infections in the past 12 months. Notably, vitamin D supplementation above 600 IU/week significantly reduced the likelihood of respiratory infections, evidenced by an odds ratio of 0.523 (p < 0.001), indicating that preschool-age children receiving a dose of vitamin D higher than 600 IU/week were about half as likely to experience respiratory infections compared to those who did not. Furthermore, no significant associations were found between sun exposure, daily sunscreen use, and the incidence of respiratory infections. Conclusively, this study underscores the potential role of vitamin D in helping the immune system against respiratory infections in preschool-age children. The observed protective effect of vitamin D supplementation suggests a potential public health strategy to mitigate the incidence of respiratory infections in preschool children on top of the already known benefits.

Preventive Vitamin D Supplementation and Risk for COVID-19 Infection: A Systematic Review and Meta-Analysis

Over the past few decades, vitamin D has been found to play a crucial role in bone homeostasis, muscle function, oncogenesis, immune response and metabolism. In the context of the COVID-19 pandemic, numerous researchers have tried to determine the role vitamin D might play in the immune response to the virus. The aim of this systematic review and meta-analysis is to demonstrate that preventive vitamin D supplementation can play a protective role in the incidence of COVID-19, mortality and admission to intensive care units (ICUs). A comprehensive search on the PubMed/MEDLINE, Scopus, Cochrane and Google Scholar databases was performed on 15 May 2023, and two of the authors independently screened the literature. As effect measures, we calculated the Odds Ratios with their corresponding 95% confidence intervals (ICs). The assessment of potential bias and the evaluation of study quality will be conducted independently by two researchers. Sixteen publications were selected for inclusion in the meta-analysis. Our findings indicate that vitamin D supplementation has a protective effect against the incidence of COVID-19 in RCT studies (OR 0.403, 95% IC 0.218, 0.747), in the incidence of COVID-19 in analytical studies (OR = 0.592, 95% IC 0.476-0.736) and in ICU admission (OR 0.317, 95% IC 0.147-0.680). Subsequent analyses were conducted by type of subject treated (patient/healthcare workers) and type of supplementation (vitamin D vs. placebo/no treatment or high dose vs. low dose). Our meta-analysis suggests a definitive and significant association between the protective role of vitamin D and COVID-19 incidence and ICU admission.

COVID-19 and Bone Loss: A Review of Risk Factors, Mechanisms, and Future Directions

PURPOSE OF REVIEW

SARS-CoV-2 drove the catastrophic global phenomenon of the COVID-19 pandemic resulting in a multitude of systemic health issues, including bone loss. The purpose of this review is to summarize recent findings related to bone loss and potential mechanisms.

RECENT FINDINGS

The early clinical evidence indicates an increase in vertebral fractures, hypocalcemia, vitamin D deficiencies, and a loss in BMD among COVID-19 patients. Additionally, lower BMD is associated with more severe SARS-CoV-2 infection. Preclinical models have shown bone loss and increased osteoclastogenesis. The bone loss associated with SARS-CoV-2 infection could be the result of many factors that directly affect the bone such as higher inflammation, activation of the NLRP3 inflammasome, recruitment of Th17 cells, the hypoxic environment, and changes in RANKL/OPG signaling. Additionally, SARS-CoV-2 infection can exert indirect effects on the skeleton, as mechanical unloading may occur with severe disease (e.g., bed rest) or with BMI loss and muscle wasting that has also been shown to occur with SARS-CoV-2 infection. Muscle wasting can also cause systemic issues that may influence the bone. Medications used to treat SARS-CoV-2 infection also have a negative effect on the bone. Lastly, SARS-CoV-2 infection may also worsen conditions such as diabetes and negatively affect kidney function, all of which could contribute to bone loss and increased fracture risk. SARS-CoV-2 can negatively affect the bone through multiple direct and indirect mechanisms. Future work will be needed to determine what patient populations are at risk of COVID-19-related increases in fracture risk, the mechanisms behind bone loss, and therapeutic options. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.