Iuliana Soldanescu

Vitamin D is a secosteroid hormone traditionally recognized for its role in bone and mineral metabolism, but it is increasingly understood to also function as an important immunomodulator influencing susceptibility to and outcomes of infectious diseases. This narrative review summarizes current evidence on the immunological, clinical, and preventive effects of vitamin D in the context of novel coronavirus disease (COVID-19), post-acute sequelae of SARS-CoV-2 infection (long COVID), and influenza. Mechanistically, vitamin D enhances innate immune defenses through the induction of antimicrobial peptides, including cathelicidin and defensins, and modulates adaptive immunity by suppressing maladaptive Th1/Th17 responses while promoting regulatory T-cell activity. Observational studies have frequently associated vitamin D deficiency with more severe COVID-19 outcomes; however, these associations may be influenced by confounding factors and reverse causality. Some meta-analyses suggest that vitamin D supplementation reduced rates of intensive care unit admission and ventilatory support, particularly among older adults and individuals with low baseline serum 25-hydroxyvitamin D concentrations. Emerging evidence also indicates that inadequate vitamin D status may be associated with an increased risk and symptom burden of long COVID, although causality has not been established. In the case of influenza, a limited number of randomized controlled trials (RCTs) and meta-analyses report a modest but statistically significant reduction in infection risk, especially with daily or weekly vitamin D supplementation in populations with low baseline vitamin D levels. Clinical guidelines consistently recommend maintaining adequate vitamin D status for general health but do not endorse high-dose vitamin D as a treatment for COVID-19 due to inconsistent trial findings. Overall, vitamin D should not be considered a standalone therapeutic agent; rather, maintaining sufficient vitamin D levels represents a low-risk, potentially beneficial strategy to support immune resilience against respiratory viral infections.

The increasing demand for high-throughput, real-time, and single-molecule protein analysis in precision medicine has propelled the development of novel sensing technologies. Among these, nanopore-based methods have garnered significant attention for their unique capabilities, including label-free detection, ultra-sensitivity, and the potential for miniaturization and portability. Originally designed for nucleic acid sequencing, nanopore technology is now being adapted for peptide and protein analysis, offering promising applications in biomarker discovery and disease diagnostics. This review examines the latest advances in biological, solid-state, and hybrid nanopores for protein sensing, focusing on their ability to detect amino acid sequences, structural variants, post-translational modifications, and dynamic protein–protein or protein–drug interactions. We critically compare these systems to conventional proteomic techniques, such as mass spectrometry and immunoassays, discussing advantages and persistent technical challenges, including translocation control and signal deconvolution. Particular emphasis is placed on recent advances in protein sequencing using biological and solid-state nanopores and the integration of machine learning and signal-processing algorithms that enhance the resolution and accuracy of protein identification. Nanopore protein sensing represents a disruptive innovation in biosensing, with the potential to revolutionize clinical diagnostics, therapeutic monitoring, and personalized healthcare.

The development of severe SARS-CoV-2 pneumonia is characterized by extensive lung inflammation, which, in turn, leads to respiratory distress and a decline in blood oxygen levels. Hospital admission, along with intensive care or ventilator usage, becomes necessary because this condition leads to serious respiratory problems. This review aims to provide a comprehensive overview of the pathophysiological mechanisms, diagnostic methods, and current therapeutic options for pneumonia caused by the SARS-CoV-2 virus. The pathophysiological process of severe pneumonia due to SARS-CoV-2 infection is characterized by direct lung damage from viral replication, an excessive immune system response, inflammation, impaired gas exchange, and multi-organ failure. The coexistence of various medical conditions leads to substantial lung impairment, resulting in hypoxia and respiratory failure, which can ultimately lead to fatal outcomes. The diagnosis of severe SARS-CoV-2 pneumonia is made through a combination of clinical, radiologic, and laboratory findings. A multifaceted approach integrating antiviral therapy, corticosteroids, oxygen supplementation, ventilatory management, and immunomodulation is imperative to control inflammation and enhance clinical outcomes. Early intervention, meticulous monitoring, and personalized care are paramount for enhancing survival and mitigating complications in critically ill patients with COVID-19 pneumonia.

Personal health records (PHRs) are digital repositories that allow individuals to access, manage, and share their health information. By enabling patients to track their health over time and communicate effectively with healthcare providers, personal health records support more personalized care and improve the quality of healthcare. Their integration with emerging technologies, such as the Internet of Things (IoT), artificial intelligence (AI), and blockchain, enhances the utility and security of health data management, facilitating continuous health monitoring, automated decision support, and secure, decentralized data exchange. Despite their potential, PHR systems face significant challenges, including privacy concerns, security issues, and digital accessibility problems. This paper discusses the fundamental concepts, requirements, system architectures, and data sources that underpin modern PHR implementations, highlighting how they enable continuous health monitoring through the integration of wearable sensors; mobile health applications; and IoT-enabled medical devices that collect, process, and transmit data to support proactive care and personalized treatments. The benefits and limitations of PHR systems are also discussed in detail, with a focus on interoperability, adoption drivers, and the role of advanced technologies in supporting the development of secure and scalable health information systems for a smarter world.

Vitamin D has emerged as a potential modulator of immune responses, sparking interest in its role in COVID-19 susceptibility and clinical outcomes. This review synthesizes current clinical evidence and explores immunological insights into the relationship between vitamin D levels and COVID-19 infection severity. Epidemiological studies indicate an inverse correlation between vitamin D deficiency and an increased risk of severe disease, hospitalization, and mortality in COVID-19 patients. Immunologically, vitamin D exerts regulatory effects on both innate and adaptive immunity, enhancing antimicrobial defense mechanisms, reducing excessive inflammatory responses, and potentially mitigating cytokine storm events observed in severe COVID-19 cases. Despite promising observational data, clinical trials evaluating vitamin D supplementation have shown mixed results, underscoring the need for standardized dosing regimens and patient stratification. Future research should focus on large-scale randomized controlled trials to conclusively determine the therapeutic potential and optimal supplementation strategies for vitamin D in managing COVID-19.

Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), has emerged as a significant health concern following the COVID-19 pandemic. Molecular mechanisms underlying the occurrence and progression of long COVID include viral persistence, immune dysregulation, endothelial dysfunction, and neurological involvement, and highlight the need for further research to develop targeted therapies for this condition. While a clearer picture of the clinical symptomatology is shaping, many molecular mechanisms are yet to be unraveled, given their complexity and high level of interaction with other metabolic pathways. This review summarizes some of the most important symptoms and associated molecular mechanisms that occur in long COVID, as well as the most relevant molecular techniques that can be used in understanding the viral pathogen, its affinity towards the host, and the possible outcomes of host-pathogen interaction.

Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), has emerged as a significant health concern following the COVID-19 pandemic. Molecular mechanisms underlying the occurrence and progression of long COVID include viral persistence, immune dysregulation, endothelial dysfunction, and neurological involvement, and highlight the need for further research to develop targeted therapies for this condition. While a clearer picture of the clinical symptomatology is shaping, many molecular mechanisms are yet to be unraveled, given their complexity and high level of interaction with other metabolic pathways. This review summarizes some of the most important symptoms and associated molecular mechanisms that occur in long COVID, as well as the most relevant molecular techniques that can be used in understanding the viral pathogen, its affinity towards the host and the possible outcomes of host-pathogen interaction.