The Role of Vitamin D in the Immune System as a Pro-survival Molecule

1,25-dihydroxyvitamin-D3 distinctly impacts the paracrine and cell-to-cell contact interactions between hPDL-MSCs and CD4+ T lymphocytes

Introduction

Human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) possess a strong ability to modulate the immune response, executed via cytokine-boosted paracrine and direct cell-to-cell contact mechanisms. This reciprocal interaction between immune cells and hPDL-MSCs is influenced by 1,25-dihydroxyvitamin-D3 (1,25(OH)2D3). In this study, the participation of different immunomodulatory mechanisms on the hPDL-MSCs-based effects of 1,25(OH)2D3 on CD4+ T lymphocytes will be elucidated using different co-culture models with various cytokine milieus.

Material and methods

hPDL-MSCs and CD4+ T lymphocytes were co-cultured indirectly and directly with inserts (paracrine interaction only) or directly without inserts (paracrine and direct cell-to-cell contact interaction). They were stimulated with TNF-α or IL-1β in the absence/presence of 1,25(OH)2D3. After five days of co-cultivation, the CD4+ T lymphocyte proliferation, viability, and cytokine secretion were analyzed. Additionally, the gene expression of soluble and membrane-bound immunomediators was determined in hPDL-MSCs.

Results

In the indirect and direct co-culture model with inserts, 1,25(OH)2D3 decreased CD4+ T lymphocyte proliferation and viability. The direct co-culture model without inserts caused the opposite effect. 1,25(OH)2D3 mainly decreased the CD4+ T lymphocyte-associated secretion of cytokines via hPDL-MSCs. The degree of these inhibitions varied between the different co-culture setups. 1,25(OH)2D3 predominantly decreased the expression of the soluble and membrane-bound immunomediators in hPDL-MSCs to a different extent, depending on the co-culture models. The degree of all these effects depended on the absence and presence of exogenous TNF-α and IL-1β.

Conclusion

These data assume that 1,25(OH)2D3 differently affects CD4+ T lymphocytes via the paracrine and direct cell-to-cell contact mechanisms of hPDL-MSCs, showing anti- or pro-inflammatory effects depending on the co-culture model type. The local cytokine microenvironment seems to be involved in fine-tuning these effects. Future studies should consider this double-edged observation by executing different co-culture models in parallel.

Vitamin D Deficiency as a Risk Factor of Tinnitus: An Epidemiological Study

OBJECTIVES

Vitamin D deficiency as a risk factor of tinnitus has not been well known. We tried to evaluate the association between the serum 25-(OH) vitamin D levels and tinnitus among the Korean population to propose the possible role of serum vitamin D in patients with tinnitus.

METHODS

This cross-sectional study investigated the potential risk factors of tinnitus in relation to serum 25(OH)D levels within the Korean population. It encompassed a health interview, nutrition assessment, and a health examination. Data was sourced from the KNHANES V (2010-2012), conducted by the Division of Health and Nutritional Survey under the Korean Centers for Disease Control and Prevention (KCDCP). Participants were chosen from various sampling units categorized by geography, gender, and age group. The selection was facilitated through household registries using a stratified, multistage, clustered probability sampling approach.

RESULTS

Data of 16 408 subjects were collected in this study. There were significant differences in gender, economic status, educational level, and sun exposure duration between the tinnitus and non-tinnitus groups. Serum 25(OH) vitamin D level between hearing loss and normal hearing was also significantly different. The logistic regression models with serum 25(OH) vitamin D quartile and tinnitus as the dependent variable, which were controlled for age, sex, smoking status, BMI, diabetes, hypertension, sun exposure, regular exercise, income, and education, eventually demonstrated that serum vitamin D deficiency and low sun exposure duration significantly increased the risk of tinnitus development.

CONCLUSION

This study demonstrated a significant association between serum vitamin D levels and tinnitus, driven by large epidemiological data. The results of our study provide baseline data for further research to investigate the role of vitamin D in the pathogenesis and management of tinnitus.

Evaluating the Impact of Vitamin D3 on NF-κB and JAK/STAT Signaling Pathways in Drosophila melanogaster

This study delved into the consequences of prolonged administration of vitamin D3 on innate immune systems, particularly NF-κB and JAK/STAT, in Drosophila melanogaster. The outcomes indicated that vitamin D3 treatment exhibited a notable capacity to improve the survival of adult flies with compromised immune functions, a condition induced by the loss of PGRP-LB, particularly when the flies were exposed to heat-killed Escherichia coli. The PGRP-LBΔ mutant line that was treated with heat-killed E. coli experienced reduced survival. Treatment of heat-killed E. coli-treated PGRP-LBΔ with vitamin D3 resulted in improved survival, and this phenotypic feature might be due to the downregulation of gene expression in the NF-κB and JAK/STAT pathways. However, a higher concentration of vitamin D3 was associated with decreased survival, potentially linked to intricate immunological responses. The research also underscored the influence of vitamin D3 on the expression of antioxidant genes, sod1 and sod2, indicating an augmented resistance to oxidative stress. Further, this study revealed the effect of vitamin D3 on the reproductive status of the autoinflammatory model, showing an increase in pupae and adult flies with a treatment of 10 mM vitamin D3, suggesting the potential benefits of vitamin D3 on the reproductive profile. Overall, this study provides preliminary insights into the complex interactions between vitamin D3, immune pathways, oxidative responses in the cell, and reproduction in Drosophila.

Advances in the Treatment of Autism Spectrum Disorder: Current and Promising Strategies

Autism spectrum disorder (ASD) is an umbrella term for developmental disorders characterized by social and communication impairments, language difficulties, restricted interests, and repetitive behaviors. Current management approaches for ASD aim to resolve its clinical manifestations based on the type and severity of the disability. Although some medications like risperidone show potential in regulating ASD-associated symptoms, a comprehensive treatment strategy for ASD is yet to be discovered. To date, identifying appropriate therapeutic targets and treatment strategies remains challenging due to the complex pathogenesis associated with ASD. Therefore, a comprehensive approach must be tailored to target the numerous pathogenetic pathways of ASD. From currently viable and basic treatment strategies, this review explores the entire field of advancements in ASD management up to cutting-edge modern scientific research. A novel systematic and personalized treatment approach is suggested, combining the available medications and targeting each symptom accordingly. Herein, summarize and categorize the most appropriate ways of modern ASD management into three distinct categories: current, promising, and prospective strategies.

Regulation of Dendritic Cell Functions by Vitamins as Promising Therapeutic Strategy for Immune System Disorders

A functional immune system is crucial for a healthy life, protecting from infections, tumors, or autoimmune disorders; these are accomplished by the interaction between various immune cells. Nourishment, particularly micronutrients, are very important components in the immune system balance, therefore this review emphasizes the vitamins (D, E, A, C) and Dendritic cells' subsets due to vitamins' roles in immune processes, especially on dendritic cells' functions, maturation, and cytokine production. Current studies reveal significant benefits related to vitamins, including vitamin E, which can contribute to the control of dendritic cells' function and maturation. Furthermore, vitamin D plays an immunoregulatory and anti-inflammatory role in the immune system. Metabolite of vitamin A which is called retinoic acid leads to T cells' differentiation to T helper 1 or T helper 17, so low levels of this vitamin exacerbate the menace of infectious diseases, and vitamin C has anti-oxidant effects on dendritic cells and modulate their activation and differentiation program. Additionally, the correlation between the amount of vitamin and the occurrence or progression of allergic diseases and autoimmunity disorders is discussed according to the results of previous studies.

Nutrition and immunity: lessons from coronavirus disease-2019

This review will provide an overview of the immune system and then describe the effects of frailty, obesity, specific micronutrients and the gut microbiota on immunity and susceptibility to infection including data from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic where relevant. A key role for the immune system is providing host defence against pathogens. Impaired immunity predisposes to infections and to more severe infections and weakens the response to vaccination. A range of nutrients, including many micronutrients, play important roles in supporting the immune system to function. The immune system can decline in later life and this is exaggerated by frailty. The immune system is also weakened with obesity, generalised undernutrition and micronutrient deficiencies, which all result in increased susceptibility to infection. Findings obtained during the SARS-CoV-2 pandemic support what was already known about the effects of ageing, frailty and obesity on immunity and susceptibility to infection. Observational studies conducted during the pandemic also support previous findings that multiple micronutrients including vitamins C, D and E, zinc and selenium and long-chain n-3 fatty acids are important for immune health, but whether these nutrients can be used to treat those already with coronavirus disease discovered in 2019 (COVID-19), particularly if already hospitalised, is uncertain from current inconsistent or scant evidence. There is gut dysbiosis in patients with COVID-19 and studies with probiotics report clinical improvements in such patients. There is an inverse association between adherence to a healthy diet and risk of SARS-CoV-2 infection and hospitalisation with COVID-19 which is consistent with the effects of individual nutrients and other dietary components. Addressing frailty, obesity and micronutrient insufficiency will be important to reduce the burden of future pandemics and nutritional considerations need to be a central part of the approach to preventing infections, optimising vaccine responses and promoting recovery from infection.

Lower vitamin D levels are associated with the pathogenesis of inflammatory bowel diseases

Vitamin D plays a role in regulating immune homeostasis, inflammation and has an impact on the pathogenesis of inflammatory bowel diseases (IBD). IBD has a multifactorial pathogenesis primarily associated with immune dysregulation, dysbiosis, structurally altered intestinal mucosa, and genetic factors. The immunomodulatory function of this vitamin is linked to its control over innate and adaptive immunity, facilitated through its nuclear vitamin D receptor, leading to the inhibition of nuclear factor kappa-B. This study aimed to investigate serum vitamin D levels in patients with IBD compared to healthy individuals and to evaluate the relationship between vitamin D and inflammatory markers. Cross-sectional study. The study included 106 participants divided into 2 groups: patients with IBD (92), and healthy controls (14). The diagnosis of IBD was based on clinical, laboratory, fecal, endoscopic, and histological findings, following the European guidelines for diagnosis and follow-up ECCO-ESGAR guidelines for diagnostic assessment of IBD from 2019. Serum vitamin D levels were measured along with laboratory tests, imaging, and endoscopic examinations. IBD activity was evaluated using the Montreal classification and clinical and endoscopic indices. Data analysis involved calculating the mean, minimum, and maximum values, standard deviation, and Pearson coefficient. The level of statistical significance for this study was set at P < .05. The study found a prevalence of vitamin D deficiency in 32.6% of patients with IBD, while 66.3% had insufficiency, as compared with healthy individuals. The mean levels of vitamin D in UC and CD were 16 ± 8.6 ng/mL, whereas in the control healthy group, they were 26 ± 9.73 ng/mL. A statistically significant reverse correlation was observed between lower vitamin D levels and higher levels of the inflammatory markers. The study concluded that IBD patients exhibit lower levels of vitamin D, which is associated with inflammation and may contribute to the pathogenesis of the disease.

Neuroimmunological Effect of Vitamin D on Neuropsychiatric Long COVID Syndrome: A Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19). COVID-19 is now recognized as a multiorgan disease with a broad spectrum of manifestations. A substantial proportion of individuals who have recovered from COVID-19 are experiencing persistent, prolonged, and often incapacitating sequelae, collectively referred to as long COVID. To date, definitive diagnostic criteria for long COVID diagnosis remain elusive. An emerging public health threat is neuropsychiatric long COVID, encompassing a broad range of manifestations, such as sleep disturbance, anxiety, depression, brain fog, and fatigue. Although the precise mechanisms underlying the neuropsychiatric complications of long COVID are presently not fully elucidated, neural cytolytic effects, neuroinflammation, cerebral microvascular compromise, breakdown of the blood-brain barrier (BBB), thrombosis, hypoxia, neurotransmitter dysregulation, and provoked neurodegeneration are pathophysiologically linked to long-term neuropsychiatric consequences, in addition to systemic hyperinflammation and maladaptation of the renin-angiotensin-aldosterone system. Vitamin D, a fat-soluble secosteroid, is a potent immunomodulatory hormone with potential beneficial effects on anti-inflammatory responses, neuroprotection, monoamine neurotransmission, BBB integrity, vasculometabolic functions, gut microbiota, and telomere stability in different phases of SARS-CoV-2 infection, acting through both genomic and nongenomic pathways. Here, we provide an up-to-date review of the potential mechanisms and pathophysiology of neuropsychiatric long COVID syndrome and the plausible neurological contributions of vitamin D in mitigating the effects of long COVID.

Immunomodulatory actions of vitamin D in various immune-related disorders: a comprehensive review

For many years, vitamin D has been acknowledged for its role in maintaining calcium and phosphate balance. However, in recent years, research has assessed its immunomodulatory role and come up with conflicting conclusions. Because the vitamin D receptor is expressed in a variety of immune cell types, study into the precise role of this molecule in diseases, notably autoimmune disorders, has been made possible. The physiologically activated version of vitamin D also promotes a tolerogenic immunological condition in addition to modulating innate and acquired immune cell responses. According to a number of recent studies, this important micronutrient plays a complex role in numerous biochemical pathways in the immune system and disorders that are associated with them. Research in this field is still relatively new, and some studies claim that patients with severe autoimmune illnesses frequently have vitamin D deficiencies or insufficiencies. This review seeks to clarify the most recent research on vitamin D's immune system-related roles, including the pathophysiology of major disorders.

The Role of Vitamins in the Pathogenesis of Asthma

Vitamins play a crucial role in the proper functioning of organisms. Disturbances of their levels, seen as deficiency or excess, enhance the development of various diseases, including those of the cardiovascular, immune, or respiratory systems. The present paper aims to summarize the role of vitamins in one of the most common diseases of the respiratory system, asthma. This narrative review describes the influence of vitamins on asthma and its main symptoms such as bronchial hyperreactivity, airway inflammation, oxidative stress, and airway remodeling, as well as the correlation between vitamin intake and levels and the risk of asthma in both pre- and postnatal life.

Difference in Levels of Vitamin D between Indoor and Outdoor Athletes: A Systematic Review and Meta-Analysis

Vitamin D, its importance in different processes taking place in the human body, the effects of abnormal levels of this hormone, either too low or too high, and the need for supplementation have been extensively researched thus far. Variances in exposure to sunlight can cause vitamin D levels to fluctuate. Indoor activity can be a factor for these fluctuations and can lead to a decrease in vitamin D levels. We conducted a systematic review and meta-analysis aiming to identify whether indoor compared to outdoor training has a significant influence on vitamin D levels; we also performed subgroup analyses and multivariate meta-regression. The type of training has an impact on vitamin D levels that is influenced by multiple cofounders. In a subgroup analysis not considering cofounders, the mean serum vitamin D was 3.73 ng/mL higher in outdoor athletes, a difference which barely fails to achieve significance (p = 0.052, a total sample size of 5150). The indoor-outdoor difference is only significant (clinically and statistically) when considering studies performed exclusively on Asian athletes (a mean difference of 9.85 ng/mL, p < 0.01, and a total sample size of 303). When performing the analyses within each season, no significant differences are observed between indoor and outdoor athletes. To control for multiple cofounders (the season, latitude, and Asian/Caucasian race) simultaneously, we constructed a multivariate meta-regression model, which estimated a serum vitamin D concentration lower by 4.446 ng/mL in indoor athletes. While a multivariate model suggests that outdoor training is associated with slightly higher vitamin D concentrations when controlling for the season, latitude, and Asian/Caucasian race, the type of training has a numerically and clinically small impact. This suggests that vitamin D levels and the need for supplementation should not be decided based on training type alone.

Vitamin D receptor genetic polymorphisms in severe and recurrent tuberculosis in children

AIM

To analyze the genetic polymorphisms of vitamin D receptor FokI, TaqI, ApaI and BsmI gene polymorphisms in children with severe and recurrent tuberculosis (TB).

METHODS

A prospective, observational study was conducted in 35 children with severe and recurrent TB referred to our Pediatric TB clinic at a tertiary referral center for children. The blood samples were analysed for genetic polymorphisms of Vitamin D receptor with respect to FokI, TaqI, ApaI and BsmI genotypes and their individual alleles and association of various clinical and laboratory parameters were analysed.

RESULT

Ten (28.6%) children had recurrent TB and 26 (74.3%) had severe TB. The severity of TB was not associated with Ff and ff polymorphism of FokI (Odd's ratio 7.88) as compared to no FokI polymorphism. Absence of FokI polymorphism was associated with recurrent lymph node TB (Odds ratio 3.429). Presence of Tt polymorphism of TaqI (p = 0.04) and Fok1 Polymorphism [Odds ratio 7.88] were not associated with recurrent TB.

CONCLUSION

Recurrent TB was absent in presence of Tt polymorphism of TaqI. Severe TB was not associated polymorphism of Vitamin D receptor polymorphisms.

Neuroinflammation in Alzheimer's disease: potential beneficial effects of vitamin D

Alzheimer's disease (AD) is the most common cause of dementia. In recent years, several studies have robustly shown that neuroinflammation plays a crucial role in the pathophysiology of this disease. The co-localization of amyloid-β plaques near activated glial cells and the increased levels of inflammatory cytokines in AD patients indicate the involvement of the neuroinflammatory process in AD progression. Considering that pharmacological treatment remains a challenge for the management of this disease, compounds with anti-inflammatory and antioxidant properties are promising therapeutic strategies. In this context, vitamin D has gained attention in the last few years due to its neuroprotective property and the high prevalence of vitamin D deficiency in the population. Herein, in this narrative review we present the possible contribution of the antioxidant and anti-inflammatory properties of vitamin D for its neuroprotective effects, and the clinical and preclinical data dealing with the effects of vitamin D in AD, focusing mainly on the neuroinflammatory process.

25-hydroxyvitamin D3 generates immunomodulatory plasticity in human periodontal ligament-derived mesenchymal stromal cells that is inflammatory context-dependent

Introduction

Human periodontal ligament-derived mesenchymal stromal cells (hPDL-MSCs) exhibit a tight bi-directional interaction with CD4+ T lymphocytes. The hPDL-MSCs' immunomodulatory abilities are drastically enhanced by pro-inflammatory cytokines via boosting the expression of various immunomediators. 25-hydroxyvitamin D3 (25(OH)D3), the major metabolite of vitamin D3 in the blood, affects both hPDL-MSCs and CD4+ T lymphocytes, but its influence on their interaction is unknown.

Methods

Therefore, primary hPDL-MSCs were stimulated in vitro with tumor necrosis factor (TNF)-α a or interleukin (IL)-1β in the absence and presence of 25(OH)D3 followed by an indirect co-culture with phytohemagglutinin-activated CD4+ T lymphocytes. The CD4+ T lymphocyte proliferation, viability, and cytokine secretion were analyzed. Additionally, the expression of various immunomediators in hPDL-MSCs was investigated, and their implication was verified by using pharmacological inhibitors.

Results

25(OH)D3 significantly counteracted the suppressive effects of IL-1β-treated hPDL-MSCs on CD4+ T lymphocyte proliferation, whereas no effects were observed in the presence of TNF-α. Additionally, 25(OH)D3 significantly increased the percentage of viable CD4+ T lymphocytes via TNF-α- or IL-1β-treated hPDL-MSCs. It also caused a significant decrease in interferon-γ, IL-17A, and transforming growth factor-β productions, which were triggered by TNF-α-treated hPDL-MSCs. 25(OH)D3 significantly decreased the production of various immunomediators in hPDL-MSCs. Inhibition of two of them, prostaglandin E2 and indoleamine-2,3-dioxygenase-1, partially abolished some of the hPDL-MSCs-mediated effects of 25(OH)D3 on CD4+ T lymphocytes.

Conclusion

These data indicate that 25(OH)D3 influences the immunomodulatory activities of hPDL-MSCs. This modulatory potential seems to have high plasticity depending on the local cytokine conditions and may be involved in regulating periodontal tissue inflammatory processes.

Discussion on the Clinical Course of Adverse Effects after COVID-19 Vaccination: A Retrospective Analysis of Case Series in an Outpatient Department

BACKGROUND

A total of 8,303 individuals (4.3%) with adverse reactions (n=191,860) after vaccination developed serious conditions or died. Such health developments could cause people not vaccinated yet or waiting for a booster shot to become fearful of the vaccination.

METHODS

The 3-month (July-September 2021) clinical data of 41 patients from the family medicine department of a single medical center were analyzed retrospectively to determine risk factors and to investigate the clinical course to identify the cause of symptoms in detail.

RESULTS

A significant number of older adults aged over 50 years reported experiencing general weakness (P=0.026) but fewer incidences of fever than patients aged 50 years or younger (P=0.011). Eighteen of the 41 patients were requested to visit more than twice or consult a specialist. In 14 patients, the symptoms were explained by other medical causes.

CONCLUSION

The primary physician has a pivotal role in thoroughly evaluating patients who complain of adverse effects after vaccination, considering the broad multitude of symptoms and medical conditions presented. To thoroughly evaluate and appropriately advise patients with adverse reactions to their chosen vaccine, taking detailed medical history and nutritional counseling are required to identify possible underlying causes, resolve symptoms, and educate them on self-care and regarding vaccines.

Vitamin D supplementation and lower respiratory tract infection in infants: a nested case-control study

PURPOSE

To assess the association between vitamin D (VD) supplementation and the risk of lower respiratory tract infection (LRTI) among infants.

METHODS

This is a nested case-control study from an ongoing prospective birth cohort in Wuhan from 2013. Cases were subjects free of neonatal pneumonia but later developed LRTI during infancy, who were matched with five randomly selected controls by infant sex, birth year, and birth season. We included 190 cases and 950 controls in the final analysis. The primary outcome was the first LRTI incident and the exposure was VD supplementation from birth to the index endpoint. The association between VD supplementation and LRTI risk was assessed using the Cox proportional-hazards regression model.

RESULTS

Infants taking supplements had a 59% relative reduction in the hazard ratio of LRTI (HR = 0.41; 95% CI 0.26, 0.64) compared to those not supplemented. There was a linear relationship between LRTI risk and VD supplementation within range of 0-603 IU/day: for each 100 IU per day increment in VD supplementation, infants experienced a 21% lower risk of developing LRTI (adjusted HR: 0.79; 95% CI 0.71, 0.89). The linear relationship was stably observed in the sensitivity analyses as well.

CONCLUSIONS

VD supplementation was associated with the reduced risk of LRTI throughout infancy, and the optimal supplementation dose for infants may be beyond the current recommendation.

Vitamin D, exercise, and immune health in athletes: A narrative review

Vitamin D exerts important extra-skeletal effects, exhibiting an exquisite immune regulatory ability, affecting both innate and adaptive immune responses through the modulation of immunocyte function and signaling. Remarkably, the immune function of working skeletal muscle, which is fully recognized to behave as a secretory organ with immune capacity, is under the tight control of vitamin D as well. Vitamin D status, meaning hormone sufficiency or insufficiency, can push toward strengthening/stabilization or decline of immune surveillance, with important consequences for health. This aspect is particularly relevant when considering the athletic population: while exercising is, nowadays, the recommended approach to maintain health and counteract inflammatory processes, “too much” exercise, often experienced by athletes, can increase inflammation, decrease immune surveillance, and expose them to a higher risk of diseases. When overexercise intersects with hypovitaminosis D, the overall effects on the immune system might converge into immune depression and higher vulnerability to diseases. This paper aims to provide an overview of how vitamin D shapes human immune responses, acting on the immune system and skeletal muscle cells; some aspects of exercise-related immune modifications are addressed, focusing on athletes. The crossroad where vitamin D and exercise meet can profile whole-body immune response and health.

Vitamin D: a potentially important secosteroid for coping with COVID-19

COVID-19 is a disease that has caused a high number of deaths in the world, and despite being controlled, it requires attention and the search for new quick and economical therapeutic strategies. In this sense, vitamin D stands out, an immunomodulator that has shown beneficial effects in decreasing the risk and severity of acute respiratory tract infections, including COVID-19. Therefore, this review presents a number of experimental, observational and clinical studies on the importance of vitamin D against viral infections with an emphasis on COVID-19, highlighting the relationship between vitamin D, Renin-Angiotensin System and cytokine storms with decreased inflammatory lesions in patients with COVID-19. In addition, aspects of pathophysiology, metabolism, risk factors, sources and recommendations of vitamin D are described. We conclude that vitamin D plays a protective role against inflammatory lesions and can decrease the risk of infections and the severity of COVID-19. Therefore, it is essential to maintain adequate levels of vitamin D to avoid complications related to its deficiency.

Vitamin D3 in acute respiratory infections in patients under five years old (Cartagena de Indias, Colombia)

Background and Aim. Low serum levels of 25-hydroxyvitamin D3 are associated with an increased risk of Acute Respiratory Infection (ARI) that is among the most important causes of morbidity and mortality in children under 5 years old. We describe the clinical behavior of acute respiratory infections in patients under five years ago in one sanitary institution in Colombia after VD3 supplementation. Material and Methods. A case series was conducted on 38 patients of both genders aged less to 5 years ago was included. Participants were supplied 50,000 units of VD3 orally each month for three months. The number of events, consultations for emergency services, and hospitalization due to acute respiratory infections (ARIs) before and after VD3 administration were described. Results. The average age of the participants was 25.81 ± 17.50 months. The average clinical ARIs per month was 4.02 (95% CI 3.64-4.40) before VD3 administration. Fewer episodes at the end of the three cycles was found at 2.23/month (95% CI 1.81-2.65; p=0.0230). The average consultations for emergency services during the three months before VD3 administration was 2.15 (95% CI 1.77-2.53). After three months of treatment, the average use of emergency services decreased to 0.52 (95% CI 0.37-0.72; p=0.0180). After the administration of the three doses of VD3, only one patient required hospitalization (2.63%; : 0.026 (IC95% 0.02-0.03; p=0.0368)). Conclusions. The administration of vitamin D3 could have a benefit in decreasing the number of episodes, emergencies, and hospitalization for ARI in children under five years old. Trial studies are required to determine this potential benefit.

The HLA rs9267649 and CYP24A1 rs2248359 Variants are Associated with Multiple Sclerosis: A Study on Iranian Population

BACKGROUND

Studies have shown that MS results from synergism between genetic and environmental factors. As a genetic factor, the rs9267649 variant through the regulatory effect on the HLA-DRB1 expression is involved in the MS development. In addition, vitamin D deficiency through involvement of rs2248359 variant of CYP24A1 has shown to play important role in the risk of MS.

OBJECTIVES

The aim of this study was to investigate both the HLA rs9267649 and CYP24A1 rs2248359 variants with risk of multiple sclerosis (MS) in Iranian population.

MATERIALS AND METHODS

The rs9267649 and rs2248359 variants were genotyped in 82 Iranian Relapsing-Remitting Multiple Sclerosis (RRMS) patients and 100 matched healthy controls, using the PCR-RFLP method. The genotype and allele frequencies were calculated and statistically analyzed.

RESULTS

A significant difference was found in the allele distribution for the both rs9267649 and rs2248359 variants, such that the A allele of rs9267649 and the C allele of rs2248359 were found to be more frequent in MS patients than in the healthy controls (p-value: 0.009, OR: 2.264, 95% CI: 1.211-4.231 and p-value: 0.028 OR: 1.594, 95% CI: 1.052-2.415), respectively.

CONCLUSIONS

The present research results provide further evidence on the association of the two variants rs9267649 of the HLA and rs2248359 of the CYP24A1 gene with MS etiology and an increased risk of MS in Iranian RRMS patients. However, further large-scale investigations in various ethnicities and in the functional genomics level are demanded to confirm our findings.

Time-Resolved Gene Expression Analysis Monitors the Regulation of Inflammatory Mediators and Attenuation of Adaptive Immune Response by Vitamin D

Peripheral blood mononuclear cells (PBMCs) belong to the innate and adaptive immune system and are highly sensitive and responsive to changes in their systemic environment. In this study, we focused on the time course of transcriptional changes in freshly isolated human PBMCs 4, 8, 24 and 48 h after onset of stimulation with the active vitamin D metabolite 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). Taking all four time points together, 662 target genes were identified and segregated either by time of differential gene expression into 179 primary and 483 secondary targets or by driver of expression change into 293 direct and 369 indirect targets. The latter classification revealed that more than 50% of target genes were primarily driven by the cells' response to ex vivo exposure than by the nuclear hormone and largely explained its down-regulatory effect. Functional analysis indicated vitamin D's role in the suppression of the inflammatory and adaptive immune response by down-regulating ten major histocompatibility complex class II genes, five alarmins of the S100 calcium binding protein A family and by affecting six chemokines of the C-X-C motif ligand family. Taken together, studying time-resolved responses allows to better contextualize the effects of vitamin D on the immune system.

Vitamin D in Inflammatory Bowel Diseases. Mechanisms of Action and Therapeutic Implications

(1) Background: Vitamin D is an immunoregulatory factor influencing intestinal homeostasis. Recent evidence supports a central role of this micronutrient in the course of Inflammatory Bowel Diseases (IBD). This narrative review aims to provide a general overview of the possible biological mechanisms of action of vitamin D and its therapeutic implications in IBD. (2) Methods: A systematic electronic search of the English literature up to October 2021 was performed using Medline and the Cochrane Library. Only papers written in English that analyzed the role of vitamin D in IBD were included. (3) Results: In vitro and animal studies reported that vitamin D signaling improves epithelial barrier integrity regulating the expression of several junctional proteins, defensins, and mucins, modulates the inflammatory response, and affects gut microbiome composition. Recent studies also suggest that vitamin D deficiency is highly prevalent among IBD patients and that low serum levels correlate with disease activity and, less clearly, with disease course. (4) Conclusions: An increasing body of evidence suggests some role of vitamin D in the pathophysiology of IBD, nonetheless the underlying mechanisms have been so far only partially elucidated. A strong correlation with disease activity has been reported but its implication in the treatment is still undefined. Thus, studies focused on this issue, the definition of vitamin D levels responsible for clinical effects, and the potential role of vitamin D as a therapeutic agent are strongly encouraged.

Ultrasound-assisted pH-shifting remodels egg-yolk low-density lipoprotein to enable construction of a stable aqueous solution of vitamin D3

Egg-yolk low-density lipoprotein (LDL) has a natural liposome structure. Using ultrasound-assisted pH-shifting (pH 12), a naturally safe and stable aqueous solution of vitamin D₃ (VD₃) was constructed employing LDL as the carrier. Images from electron microscopy showed that pH-shifting remodeled LDL molecules, resulting in a dramatic reduction in particle size (∼50%) and an increase in specific surface area, which reduced the turbidity (27.7%) and provided new interfaces for VD₃ loading. Fluorescence analyses showed that the binding of VD₃ to LDL under pH-shifting was strong, involved quenching, and the binding constant was 6.19 × 10⁴ M⁻¹. Thermogravimetric analysis and Fourier transform-infrared spectroscopy showed that pH-shifting hydrolyzed the esters in LDL to fatty acid salts, and the maximum weight loss of LDL occurred from 381.9 °C to 457.0 °C. Ultrasonic treatment enhanced the binding of LDL and VD₃ (binding constant increased to 2.56 × 10⁷ M⁻¹), reduced the particle size, and increased the ζ-potential of the complex between LDL and VD₃, thereby resulting in the improvement of solution stability and storage stability of VD₃. Ultrasound-assisted pH-shifting could remodel LDL to construct a stable aqueous solution of VD₃, which showed the potential of LDL as a carrier for lipid-soluble components.

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pH-shifting remodels LDL and results in a reduction in particle size.

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Under pH-shifting, VD₃ was bound stably to LDL with strong affinity.

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pH-shifting remodeled LDL can be used to encapsulate active ingredients.

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The binding of VD₃ to LDL was enhanced by ultrasonic treatment.

Vitamin D Treatment Sequence Is Critical for Transcriptome Modulation of Immune Challenged Primary Human Cells

Microbe-associated molecular patterns, such as lipopolysaccharide (LPS) and β-glucan (BG), are surrogates of immune challenges like bacterial and fungal infections, respectively. The biologically active form of vitamin D, 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), supports the immune system in its fight against infections. This study investigated significant and prominent changes of the transcriptome of human peripheral blood mononuclear cells that immediately after isolation are exposed to 1,25(OH)₂D₃-modulated immune challenges over a time frame of 24-48 h. In this in vitro study design, most LPS and BG responsive genes are downregulated and their counts are drastically reduced when cells are treated 24 h after, 24 h before or in parallel with 1,25(OH)₂D₃. Interestingly, only a 1,25(OH)₂D₃ pre-treatment of the LPS challenge results in a majority of upregulated genes. Based on transcriptome-wide data both immune challenges display characteristic differences in responsive genes and their associated pathways, to which the actions of 1,25(OH)₂D₃ often oppose. The joined BG/1,25(OH)₂D₃ response is less sensitive to treatment sequence than that of LPS/1,25(OH)₂D₃. In conclusion, the functional consequences of immune challenges are significantly modulated by 1,25(OH)₂D₃ but largely depend on treatment sequence. This may suggest that a sufficient vitamin D status before an infection is more important than vitamin D supplementation afterwards.

Physical Activity and Nutritional Influence on Immune Function: An Important Strategy to Improve Immunity and Health Status

Physical activity (PA) and nutrition are the essential components of a healthy lifestyle, as they can influence energy balance, promote functional ability of various systems and improve immunity. Infections and their associated symptoms are the common and frequent challenges to human health that are causing severe economic and social consequences around the world. During aging, human immune system undergoes dramatic aging-related changes/dysfunctions known as immunosenescence. Clinically, immunosenescence refers to the gradual deterioration of immune system that increases exposure to infections, and reduces vaccine efficacy. Such phenomenon is linked to impaired immune responses that lead to dysfunction of multiple organs, while lack of physical activity, progressive loss of muscle mass, and concomitant decline in muscle strength facilitate immunosenescence and inflammation. In the present review, we have discussed the role of nutrition and PA, which can boost the immune system alone and synergistically. Evidence suggests that long-term PA is beneficial in improving immune system and preventing various infections. We have further discussed several nutritional strategies for improving the immune system. Unfortunately, the available evidence shows conflicting results. In terms of interaction with food intake, PA does not tend to increase energy intake during a short time course. However, overcoming nutritional deficiencies appears to be the most practical recommendation. Through the balanced nutritious diet intake one can fulfill the bodily requirement of optimal nutrition that significantly impacts the immune system. Supplementation of a single nutrient as food is generally not advisable. Rather incorporating various fruits and vegetables, whole grains, proteins and probiotics may ensure adequate nutrient intake. Therefore, multi-nutrient supplements may benefit people having deficiency in spite of sufficient diet. Along with PA, supplementation of probiotics, bovine colostrum, plant-derived products and functional foods may provide additional benefits in improving the immune system.

Vitamin D and COVID-19: An Overview of Recent Evidence

The novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) has progressed rapidly from an outbreak to a global pandemic, with new variants rapidly emerging. Coronavirus disease 2019 (COVID-19), the disease resulting from SARS-CoV-2 infection, can lead to multiorgan damage. Due to the extremely contagious and fatal nature of the virus, it has been a priority of medical research to find effective means of treatment. Amid this search, the role of vitamin D in modulating various aspects of the innate and adaptive immune system has been discussed. This review aims to consolidate the research surrounding the role of vitamin D in the treatment and prevention of COVID-19. While there are some conflicting results reported, the consensus is that vitamin D has a host of immunomodulatory effects which may be beneficial in the context of COVID-19 and that low levels of vitamin D can result in dysfunction of crucial antimicrobial effects, potentially contributing to poor prognosis. Studies also show that the effects of low vitamin D can be mitigated via supplementation, although the benefits of vitamin D supplementation in the treatment of COVID-19 remain controversial.

Prevalence of vitamin D deficiency and impact on clinical outcomes after kidney transplantation: a systematic review and meta-analysis

CONTEXT

The prevalence of vitamin D deficiency (VDD) and its impact on clinical outcomes after kidney transplant (KT) remain poorly defined.

OBJECTIVES

We conducted a meta-analysis to evaluate the impact of early VDD on clinical outcomes after KT.

DATA SOURCES

Electronic databases (PubMed, Embase, Web of Science, and The Cochrane Library) were systematically searched for eligible publications up to April 30, 2020.

DATA EXTRACTION

Relative risk was presented as hazard ratios (HRs) or odds ratios (ORs) and 95%CIs for dichotomous outcomes. Mean difference (MD) and 95%CIs were presented for continuous outcomes.

RESULTS

A total of 28 studies (13 prospective and 15 retrospective) were included. VDD was common early after KT, with a prevalence of 52% (95%CI: 41%-64%) at transplant, 34% (95%CI: 17%-51%) at 3 months, and 23% (95%CI: 10%-35%) at 6 months. Early VDD was associated with higher mortality rate after KT (HR, 1.56; 95%CI: 1.32-1.84; P < 0.001). In addition, early VDD led to higher risk of bacterial infection (OR, 1.82; 95%CI: 1.40-2.36; P < 0.001), BK polyomavirus infection (OR, 2.11, 95%CI: 1.23-3.61; P = 0.006), and cytomegalovirus infection (OR, 1.69; 95%CI: 1.24-2.31; P = 0.001). Early VDD increased the risk of acute rejection as well (HR, 2.28; 95%CI: 1.57-3.30; P < 0.001). Recipients with early VDD had lower estimated glomerular filtration rates (mean difference: -5.06; 95%CI: -7.28 to 2.83 mL/min; P < 0.001). Sensitivity analyses showed good stability of the pooled results.

CONCLUSION

VDD was common early after KT and associated with higher risk of death and adverse outcomes.

The Role of Micronutrients to Support Immunity for COVID-19 Prevention

The World Health Organization declared the novel coronavirus, named as SARS-CoV-2, as a global pandemic in early 2020 after the disease spread to more than 180 countries leading to tens of thousands of cases and many deaths within a couple of months. Consequently, this paper aims to summarize the evidence for the relationships between nutrition and the boosting of the immune system in the fight against the disease caused by SARS-CoV-2. This review, in particular, assesses the impact of vitamin and mineral supplements on the body's defence mechanisms against SARS-CoV-2. The results revealed that there is a strong relationship between the ingestion of biological ingredients like vitamins C-E, and minerals such as zinc, and a reduction in the effects of coronavirus infection. These can be received from either nutrition rich food sources or from vitamin supplements. Furthermore, these macromolecules might have roles to play in boosting the immune response, in the healing process and the recovery time. Hence, we recommend that eating healthy foods rich in vitamins C-E with zinc and flavonoids could boost the immune system and consequently protect the body from serious infections.

GRAPHICAL ABSTRACT

The role of vitamin A and vitamin D in modulation of the immune response with a focus on innate lymphoid cells

The immune system with its numerous and complex interactions helps to protect the host from pathogenic microorganisms, and enables cleaning of damaged tissues. It is also associated with constant "monitoring" of the appearance of malignant cells and their elimination that can occur in the human body. Such a role depends on many factors including adequate intake of nutrients, including vitamins. The effect of vitamin supplementation on the modulation of the immune response has always been the focus of numerous studies. Vitamins A and D have been shown to have the greatest immune-modulatory effect. In this review, we discuss and consider the possible roles of vitamins A and D on the immune response through innate and adaptive immune cells, with special focus on the cell population recently characterized as innate lymphoid cells. Recent literature data indicate that vitamin A and its metabolites modulate the balance between Th1 and Th2 immunity. In addition, vitamin D expresses protective effects on the innate immune system and inhibitory effects on adaptive immunity.

A Potential Role of Vitamin D on Platelet Leukocyte Aggregation and Pathological Events in Sepsis: An Updated Review

Vitamin D deficiency and sepsis are both significant global health problems. Insufficient vitamin D is considered to be a pathogenically relevant factor of sepsis-related deaths; however, a causal relationship has not yet been demonstrated. Recently, vitamin D has been an exciting field of research owing to the identification of vitamin D receptors on many extra skeletal tissues and cells, suggesting an unexpected role on body physiology, beyond its effects on bone homeostasis. However, while the role of vitamin D on bone health is widely understood and has been successfully translated into clinical applications and public health policies, recent evidence supporting its role in other physiological and pathological processes has not been fully established. In sepsis, there is an induction of local intracellular vitamin D activity by most immune cells, including lymphocytes, macrophages, neutrophils, and dendritic cells, as well as vascular endothelial cells, to ensure efficient clearance of infective microorganisms and mediate anti-inflammatory and tolerogenic effects. The literature suggests an association between low vitamin D levels and sepsis, but clinical trials have yielded contradictory results. A greater understanding of this role may improve disease management. This article reviews the available knowledge regarding vitamin D in immune function, emerging literature regarding the association between its deficiency and sepsis, as well as presenting its potential effect on platelet leukocyte aggregations (PLAs), a significant pathology in sepsis. It also summarizes clinical trials involving vitamin D supplementation during critical illness and sepsis and addresses the impact of relevant factors of sepsis pathogenesis on the efficacy of vitamin D supplementation, which could contribute to the reported inconsistencies. Looking ahead, further studies are required to uncover the possible modulatory relationship between vitamin D and sepsis to define better cut-offs for its levels, proper timing of its administration, and the optimum dosage for best management.

Vitamin D and Allergy Susceptibility during Gestation and Early Life

Worldwide, the prevalence of allergies in young children, but also vitamin D deficiency during pregnancy and in newborns is rising. Vitamin D modulates the development and activity of the immune system and a low vitamin D status during pregnancy and in early life might be associated with an increased risk to develop an allergy during early childhood. This review studies the effects of vitamin D during gestation and early life, on allergy susceptibility in infants. The bioactive form of vitamin D, 1,25(OH)2D, inhibits maturation and results in immature dendritic cells that cause a decreased differentiation of naive T cells into effector T cells. Nevertheless, the development of regulatory T cells and the production of interleukin-10 was increased. Consequently, a more tolerogenic immune response developed against antigens. Secondly, binding of 1,25(OH)2D to epithelial cells induces the expression of tight junction proteins resulting in enhanced epithelial barrier function. Thirdly, 1,25(OH)2D increased the expression of anti-microbial peptides by epithelial cells that also promoted the defense mechanism against pathogens, by preventing an invasive penetration of pathogens. Immune intervention by vitamin D supplementation can mitigate the disease burden from asthma and allergy. In conclusion, our review indicates that a sufficient vitamin D status during gestation and early life can lower the susceptibility to develop an allergy in infants although there remains a need for more causal evidence.

Circulating Vitamin D levels status and clinical prognostic indices in COVID-19 patients

BACKGROUND

Several immune mechanisms activate in COVID-19 pathogenesis. Usually, coronavirus infection is characterized by dysregulated host immune responses, interleukine-6 increase, hyper-activation of cytotoxic CD8 T lymphocytes. Interestingly, Vitamin D deficiency has been often associated with altered immune responses and infections. In the present study, we evaluated Vitamin D plasma levels in patients affected with different lung involvement during COVID-19 infection.

METHODS

Lymphocyte phenotypes were assessed by flow cytometry. Thoracic CT scan involvement was obtained by an image analysis program.

RESULTS

Vitamin D levels were deficient in (80%) of patients, insufficient in (6.5%) and normal in (13.5%). Patients with very low Vitamin D plasma levels had more elevated D-Dimer values, a more elevated B lymphocyte cell count, a reduction of CD8 + T lymphocytes with a low CD4/CD8 ratio, more compromised clinical findings (measured by LIPI and SOFA scores) and thoracic CT scan involvement.

CONCLUSIONS

Vitamin D deficiency is associated with compromised inflammatory responses and higher pulmonary involvement in COVID-19 affected patients. Vitamin D assessment, during COVID-19 infection, could be a useful analysis for possible therapeutic interventions.

TRIAL REGISTRATION

'retrospectively registered'.

Stroke-Induced Peripheral Immune Dysfunction in Vitamin D-Deficient Conditions: Modulation by Progesterone and Vitamin D

Vitamin D deficiency (Ddef) alters morphology and outcomes after a stroke. We investigated the interaction of Ddef following post-stroke systemic inflammation and evaluated whether administration of progesterone (P) or vitamin D (D) will improve outcomes. Ddef rats underwent stroke with lipopolysaccharide (LPS)-induced systemic inflammation. Rats were randomly divided into 9 groups and treated with P, D, or vehicle for 4 days. At day 4, rats were tested on different behavioral parameters. Markers of neuronal inflammation, endoplasmic reticulum stress, oxidative stress, white matter integrity, and apoptosis were measured along with immune cell populations from the spleen, thymus, and blood. Severely altered outcomes were observed in the Ddef group compared to the D-sufficient (Dsuf) group. Stroke caused peripheral immune dysfunction in the Dsuf group which was worse in the Ddef group. Systemic inflammation exacerbated injury outcomes in the Dsuf group and these were worse in the Ddef group. Monotherapy with P/D showed beneficial functional effects but the combined treatment showed better outcomes than either alone. Ddef as a comorbid condition with stroke worsens stroke outcomes and can delay functional recovery. Combination treatment with P and D might be promising for future stroke therapeutics in Ddef.

Serum 25(OH)D Level on Hospital Admission Associated With COVID-19 Stage and Mortality

OBJECTIVES

Vitamin D deficiency was previously correlated with incidence and severity of coronavirus disease 2019 (COVID-19). We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) level on admission and radiologic stage and outcome of COVID-19 pneumonia.

METHODS

A retrospective observational trial was done on 186 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals hospitalized from March 1, 2020, to April 7, 2020, with combined chest computed tomography (CT) and 25(OH)D measurement on admission. Multivariate regression analysis was performed to study if vitamin D deficiency (25(OH)D <20 ng/mL) correlates with survival independently of confounding comorbidities.

RESULTS

Of the patients with COVID-19, 59% were vitamin D deficient on admission: 47% of females and 67% of males. In particular, male patients with COVID-19 showed progressively lower 25(OH)D with advancing radiologic stage, with deficiency rates increasing from 55% in stage 1 to 74% in stage 3. Vitamin D deficiency on admission was not confounded by age, ethnicity, chronic lung disease, coronary artery disease/hypertension, or diabetes and was associated with mortality (odds ratio [OR], 3.87; 95% confidence interval [CI], 1.30-11.55), independent of age (OR, 1.09; 95% CI, 1.03-1.14), chronic lung disease (OR, 3.61; 95% CI, 1.18-11.09), and extent of lung damage expressed by chest CT severity score (OR, 1.12; 95% CI, 1.01-1.25).

CONCLUSIONS

Low 25(OH)D levels on admission are associated with COVID-19 disease stage and mortality.

The impact of vitamin D supplementation on mortality rate and clinical outcomes of COVID-19 patients: A systematic review and meta-analysis.. [DOI: 10.1101/2021.01.04.21249219]

Background

Several studies have suggested the positive impact of vitamin D on patients infected with SARS-CoV-2. This systematic review aims to evaluate the effects of vitamin D supplementation on clinical outcomes and mortality rate of COVID-19 patients.

Methods

A comprehensive search was conducted through the databases of PubMed, Scopus, Web of Knowledge, Embase, Ovid, and The Cochrane Library with no limitation in time and language, until December 16, 2020. The results were screened based on their accordance with the subject. Two independent reviewers selected the eligible studies and the outcomes of interest were extracted. Using the Joanna Briggs Institute (JBI) Critical Appraisal Tools for Randomized Controlled Trials (RCTs) and Quasi-Experimental Studies, the remaining results were appraised critically. Statistical analysis was performed using the Comprehensive Meta-Analysis (CMA) software version 2.0.

Results

Of the 2311 results, 1305 duplicated results were removed. After screening the titles, abstracts, and the full-text articles of the remaining records, four studies and 259 patients were enrolled, including 139 patients in vitamin D intervention groups. In three of the studies, the patients’ survival and mortality rate were evaluated. The pooled analysis of these studies showed a significantly lower mortality rate among the intervention groups (10.56%) compared with the control groups (23.88%) (OR = 0.264, 95% CI = 0.099–0.708, p-value = 0.008). Two of the studies reported the clinical outcomes based on the World Health Organization’s Ordinal Scale for Clinical Improvement (OSCI) score for COVID-19, where both of them showed a significant decrease in OSCI score in the vitamin D intervention groups. Additionally, One study reported a lower rate of intensive care unit (ICU) admission, and one study reported a significant decrease in serum levels of Fibrinogen.

Conclusion

Prescribing vitamin D supplementation to patients with COVID-19 infection seems to decrease the mortality rate, the severity of the disease, and serum levels of the inflammatory markers. Further studies are needed to determine the ideal type, dosage and duration of supplementation.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Cytokines, 25-OH vit D and disease activity in patients with juvenile-onset systemic lupus erythematosus

BACKGROUND

Juvenile onset systemic lupus erythematosus JO-SLE patients usually exhibit a more aggressive disease course compared to adult patients. Vitamin D deficiency is proposed to be associated with increased disease activity and flares of numerous autoimmune diseases like SLE, rheumatoid arthritis, and scleroderma.

OBJECTIVE

To evaluate the level of IL-17, IFN-γ, and 25-OH Vit D in JO-SLE patients versus healthy controls, and determine the correlation of those inflammatory mediators with SLE disease activity and damage scores. Furthermore, to analyze the relationship between 25-OH Vit D levels with the inflammatory cytokines (IFN-γ and IL-17) in JO-SLE patients.

PATIENTS AND METHODS

Fifty JO-SLE patients and 25 controls were included in this study. Clinical and laboratory data of patients at the time of the study were recorded. SLE disease activity and damage were assessed using the SLEDAI-2K disease score and SLICC damage index, respectively. Plasma 25-OH Vit D, IFN-γ, and IL-17 concentrations were determined using the human ELISA kit.

RESULTS

Plasma 25-OH Vit D levels (20 ng/mL) were significantly lower in JO-SLE patients compared to (31 ng/mL) controls (P = 0.014). Plasma levels of IFN-γ and IL-17 were significantly higher (163.5 and 25.5 pg./mL) in JO-SLE patients than (68.3 and 3 pg./mL) that of controls (P = 0.016 and P = 0.013). There was a significant negative correlation between 25-OH Vit D levels and SLEDAI-2K (R= -0.431) as well as IFN-γ (R= -0.471) plasma level (P = 0.022 and P = 0.027).

CONCLUSION

IFN-γ and IL-17 were significantly higher in JO-SLE patients, while 25-OH Vit D was significantly lower compared to controls. There was a negative correlation between 25-OH Vit D and each of SLEDAI-2K and IFN-γ.

COVID-19: Is there a role for immunonutrition in obese patient?

On December 12, 2019 a new coronavirus (SARS-CoV-2) emerged in Wuhan, China, triggering a pandemic of severe acute respiratory syndrome in humans (COVID-19). Today, the scientific community is investing all the resources available to find any therapy and prevention strategies to defeat COVID-19. In this context, immunonutrition can play a pivotal role in improving immune responses against viral infections. Immunonutrition has been based on the concept that malnutrition impairs immune function. Therefore, immunonutrition involves feeding enriched with various pharmaconutrients (Omega 3 Fatty Acids, Vitamin C, Arginine, Glutamine, Selenium, Zinc, Vitamin, E and Vitamin D) to modulate inflammatory responses, acquired immune response and to improve patient outcomes. In literature, significant evidences indicate that obesity, a malnutrition state, negatively impacts on immune system functionality and on host defense, impairing protection from infections. Immunonutrients can promote patient recovery by inhibiting inflammatory responses and regulating immune function. Immune system dysfunction is considered to increase the risk of viral infections, such as SARS-CoV-2, and was observed in different pathological situations. Obese patients develop severe COVID-19 sequelae, due to the high concentrations of TNF-α, MCP-1 and IL-6 produced in the meantime by visceral and subcutaneous adipose tissue and by innate immunity. Moreover, leptin, released by adipose tissue, helps to increase inflammatory milieu with a dysregulation of the immune response. Additionally, gut microbiota plays a crucial role in the maturation, development and functions of both innate and adaptive immune system, as well as contributing to develop obese phenotype. The gut microbiota has been shown to affect lung health through a vital crosstalk between gut microbiota and lungs, called the "gut-lung axis". This axis communicates through a bi-directional pathway in which endotoxins, or microbial metabolites, may affect the lung through the blood and when inflammation occurs in the lung, this in turn can affect the gut microbiota. Therefore, the modulation of gut microbiota in obese COVID-19 patients can play a key role in immunonutrition therapeutic strategy. This umbrella review seeks to answer the question of whether a nutritional approach can be used to enhance the immune system's response to obesity in obese patients affected by COVID-19.

Vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis

There is still limited evidence regarding the influence of vitamin D in people with COVID-19. In this systematic review and meta-analysis, we analyze the association between vitamin D deficiency and COVID-19 severity, via an analysis of the prevalence of vitamin D deficiency and insufficiency in people with the disease. Five online databases-Embase, PubMed, Scopus, Web of Science, ScienceDirect and pre-print Medrevix were searched. The inclusion criteria were observational studies measuring serum vitamin D in adult and elderly subjects with COVID-19. The main outcome was the prevalence of vitamin D deficiency in severe cases of COVID-19. We carried out a meta-analysis with random effect measures. We identified 1542 articles and selected 27. Vitamin D deficiency was not associated with a higher chance of infection by COVID-19 (OR = 1.35; 95% CI = 0.80-1.88), but we identified that severe cases of COVID-19 present 64% (OR = 1.64; 95% CI = 1.30-2.09) more vitamin D deficiency compared with mild cases. A vitamin D concentration insufficiency increased hospitalization (OR = 1.81, 95% CI = 1.41-2.21) and mortality from COVID-19 (OR = 1.82, 95% CI = 1.06-2.58). We observed a positive association between vitamin D deficiency and the severity of the disease.

Vitamin D levels in liver transplantation recipients and early postoperative outcomes: Prospective observational DLiverX study

BACKGROUND & AIMS

In critically ill patients with liver disease, vitamin D deficiency is associated with higher disease severity, increased frequency of infections, and worse outcomes. This study sought to describe the trend of vitamin D in orthotopic liver transplantation (OLT) recipients and its association with outcomes.

METHODS

Prospective observational study of 67 consecutive OLT recipients enrolled between September, 2016 and August, 2017 at IRCCS-ISMETT, Palermo (Italy). Trend of vitamin D levels and potential factors influencing it levels were evaluated through a generalized linear mixed regression model.

RESULTS

Sixty-four (95.5%) recipients were vitamin D deficient (<20 ng/ml), with a median value of 8.8 ng/ml [6.2-12.9], and forty-seven of these (70.1%) showed severe deficiency (<12 ng/ml) at baseline, 7.9 ng/ml [5.4-8.9]. The baseline vitamin D showed an inverse correlation with liver disease severity: Child-Pugh, MELD score, bilirubin, INR, and organ failure (p < 0.01) at baseline. Vitamin D increased on postoperative day (POD) 28 compared with POD1: +4.5 ng/ml, C.I. 95% 3.6-5.3 ng/ml, p < 0.01. Lower baseline vitamin D, donor age, transfusion of fresh frozen plasma (negative impact, all p < 0.05), and intra-operative bypass (positive impact at POD 28, p < 0.01) were associated with variation of vitamin D levels after transplantation. Incomplete graft recovery was associated with lower vitamin D on POD28: 8.2 ± 4.4 versus 13.8 ± 9.4 ng/ml, p < 0.01; the odds ratio (OR) was 0.84; CI 95% 0.73-0.97, p = 0.014. The OR for infections within POD 28 was inversely associated with baseline vitamin D: 0.87; CI 95% 0.79-0.98, p = 0.02, and with vitamin D level at baseline <12 ng/ml: OR 6.44; CI 95% 1.66-24.94; p < 0.01.

CONCLUSIONS

Preoperative Vitamin D is correlated with disease severity, and was highly associated with invasive infection in the first 28 PODs. After OLT, the value on POD 28 had a strong association with graft function.

TaqI and ApaI Variants of Vitamin D Receptor Gene Increase the Risk of Colorectal Cancer in a Saudi Population

Background:

Polymorphisms in the gene encoding the vitamin D receptor (VDR) affect the protective role of vitamin D against many types of cancers, including colorectal cancer (CRC).

Objective:

The objective of this study was to assess the effect of four major polymorphisms of the VDR gene (ApaI, TaqI, BsmI and FokI) on the risk of CRC in a Saudi population.

Materials and Methods:

This case–control study recruited 132 CRC patients from the oncology clinics at King Abdulaziz University Hospital and 124 healthy controls from the blood bank at King Fahad General Hospital, Jeddah, Saudi Arabia, between September 2017 and August 2018. All participants were Saudis and aged 20–80 years. Genomic DNA samples were extracted from the peripheral blood cells and amplified with polymerase chain reaction. The resulting fragments were digested with different endonucleases to reveal the genotypes using the restriction fragment length polymorphism technique. The genotype distribution and allele frequency, odds ratio (OR), risk ratio (RR) and P values were determined with contingency table analysis following Hardy–Weinberg equilibrium equation.

Results:

For the ApaI single-nucleotide polymorphism (SNP) (rs7975232), only the heterozygous (Aa) genotype increased the risk of CRC (OR = 3.4, RR = 2.3, and P < 0.0001), whereas the TaqI SNP (rs731236) carriers with either the heterozygous (Tt) or homozygous (tt) genotype displayed an increased risk for the disease (OR = 6.18, RR = 4, P < 0.0001; OR = 3, RR = 2.4, P = 0.02, respectively). In contrast, heterozygous (Bb) and homozygous (bb) carriers of the BsmI SNP (rs1544410) had significantly lower risk for CRC (P < 0.0001). Finally, for the FokI SNP (rs2228570), there was no association with CRC risk.

Conclusion:

This study found that VDR SNPs ApaI and TaqI increase the risk of CRC, whereas BsmI reduces the risk of CRC in the selected Saudi population. Therefore, ApaI and TaqI SNPs could potentially be used as a diagnostic biomarker for CRC. However, the molecular mechanisms by which these variants increase or decrease the risk of CRC need to be investigated.

Mucosal vitamin D signaling in inflammatory bowel disease

Epidemiological studies have identified vitamin D (25(OH)D) deficiency to be highly prevalent among patients with inflammatory bowel disease (IBD), and low serum levels correlate with a higher disease activity and a more complicated disease course. The link to IBD pathogenesis has been subject of investigations, primarily due to the distinct immunological functions of vitamin D signaling, including anti-inflammatory and anti-fibrotic actions. Vitamin D is a pleiotropic hormone that executes its actions on cells through the vitamin D receptor (VDR). A leaky gut, i.e. an insufficient intestinal epithelial barrier, is thought to be central for the pathogenesis of IBD, and emerging data support the concept that vitamin D/VDR signaling in intestinal epithelial cells (IECs) has an important role in controlling barrier integrity. Here we review the latest evidence on how vitamin D promotes the interplay between IECs, the gut microbiome, and immune cells and thereby regulate the intestinal immune response. On the cellular level, vitamin D signaling regulates tight junctional complexes, apoptosis, and autophagy, leading to increased epithelial barrier integrity, and promotes expression of antimicrobial peptides as part of its immunomodulating functions. Further, intestinal VDR expression is inversely correlated with the severity of inflammation in patients with IBD, which might compromise the positive effects of vitamin D signaling in patients with flaring disease. Efforts to reveal the role of vitamin D in the pathophysiology of IBD will pave the road for the invention of more rational treatment strategies of this debilitating disease in the future.

Vitamin D can be effective on the prevention of COVID-19 complications: A narrative review on molecular aspects

The widespread COVID-19 pandemic has been, currently, converted to a catastrophic human health challenge. Vitamin D (VD) and its metabolites have been used as a palliative treatment for chronic inflammatory and infectious diseases from ancient times. In the current study, some molecular aspects of the potential effects of VD against COVID-19 side-effects have been discussed. An arguable role in autophagy or apoptosis control has been suggested for VD through calcium signaling at the mitochondrial and ER levels. 1,25(OH)2D3 is also an immunomodulator that affects the development of B-cells, T-cells, and NK cells in both innate and acquired immunity. The production of some anti-microbial molecules such as defensins and cathelicidins is also stimulated by VD. The overexpression of glutathione, glutathione peroxidase, and superoxide dismutase, and down-regulation of NADPH oxidase are induced by VD to reduce the oxidative stress. Moreover, the multi-organ failure due to a cytokine storm induced by SARS-CoV2 in COVID-19 may be prevented by the immunomodulatory effects of VD. It can also downregulate the renin-angiotensin system which has a protective role against cardiovascular complications induced by COVID-19. Given the many experimental and molecular evidences due to the potential protective effects of VD on the prevention of the COVID-19-induced morbidities, a VD supplementation is suggested to prevent the lethal side-effects of the infection. It is particularly recommended in VD-deficient patients or those at greater risk of serious or critical effects of COVID-19, including the elderly, and patients with pre-existing chronic diseases, especially those in nursing homes, care facilities, and hospitals.

Synthesis of peptide conjugates with vitamins for induction of antigen-specific immunotolerance

In this report, we designed conjugates of an antigen peptide with the immunosuppressive vitamins all-trans retinoic acid (ATRA) and vitamin D3 for efficient induction of antigen-specific immunotolerance. We established a synthetic scheme for the preparation of the peptide-vitamin conjugates, which the chemically unstable vitamins tolerated. Among the obtained conjugates, the ATRA conjugate successfully suppressed inflammatory effects in macrophages and dendritic cells and induced antigen presentation in dendritic cells. This synthetic method of conjugate is conceivably applicable to other antigen peptides for induction of antigen-specific immunotolerance.

The possible pathophysiology mechanism of cytokine storm in elderly adults with COVID-19 infection: the contribution of "inflame-aging"

Purpose

Novel Coronavirus disease 2019 (COVID-19), is an acute respiratory distress syndrome (ARDS), which is emerged in Wuhan, and recently become worldwide pandemic. Strangely, ample evidences have been shown that the severity of COVID-19 infections varies widely from children (asymptomatic), adults (mild infection), as well as elderly adults (deadly critical). It has proven that COVID-19 infection in some elderly critical adults leads to a cytokine storm, which is characterized by severe systemic elevation of several pro-inflammatory cytokines. Then, a cytokine storm can induce edematous, ARDS, pneumonia, as well as multiple organ failure in aged patients. It is far from clear till now why cytokine storm induces in only COVID-19 elderly patients, and not in young patients. However, it seems that aging is associated with mild elevated levels of local and systemic pro-inflammatory cytokines, which is characterized by “inflamm-aging”. It is highly likely that “inflamm-aging” is correlated to increased risk of a cytokine storm in some critical elderly patients with COVID-19 infection.

Methods

A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar pre-print database using all available MeSH terms for COVID-19, Coronavirus, SARS-CoV-2, senescent cell, cytokine storm, inflame-aging, ACE2 receptor, autophagy, and Vitamin D. Electronic database searches combined and duplicates were removed.

Results

The aim of the present review was to summarize experimental data and clinical observations that linked the pathophysiology mechanisms of “inflamm-aging”, mild-grade inflammation, and cytokine storm in some elderly adults with severe COVID-19 infection.

Association of vitamin D with fatty acids in pregnancy

Preeclampsia is a pregnancy complication, associated with an increased risk of maternal and neonatal morbidity and mortality. The etiology of preeclampsia is not yet fully understood, although the current literature indicates an up regulation of inflammatory mediators. Vitamin D is known to have anti-inflammatory properties and influence vascular function. Fatty acids are also known to regulate inflammation in pregnancy. This study was carried out to explore the association of maternal vitamin D and fatty acids in pregnancy. The present study includes 69 normotensive control (NC) and 50 women with preeclampsia (PE). Maternal and cord serum 25-hydroxyvitamin D [25(OH)D] levels were lower (p<0.01for both) in women with PE compared to NC women. Maternal plasma total polyunsaturated fatty acids (PUFA) levels were lower (p<0.05) while levels of total saturated fatty acids (SFA) and total monounsaturated fatty acids (MUFA) were higher (p<0.05 for both) in women with PE. Cord erythrocyte PUFA levels were higher (p<0.01) in PE women. Maternal 25(OH)D levels were negatively associated with maternal systolic and diastolic BP (p<0.01 for both). Maternal 25(OH)D levels were positively associated with maternal total PUFA (p<0.01) and negatively associated with maternal total SFA (p<0.05), total MUFA (p<0.01). This study for the first time demonstrates an association of maternal vitamin D with fatty acid levels in pregnancy. Our results suggest that vitamin D and fatty acids may work in concert to regulate fetal growth.

Vitamin D in Triple-Negative and BRCA1-Deficient Breast Cancer-Implications for Pathogenesis and Therapy

Several studies show that triple-negative breast cancer (TNBC) patients have the lowest vitamin D concentration among all breast cancer types, suggesting that this vitamin may induce a protective effect against TNBC. This effect of the active metabolite of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D), can be attributed to its potential to modulate proliferation, differentiation, apoptosis, inflammation, angiogenesis, invasion and metastasis and is supported by many in vitro and animal studies, but its exact mechanism is poorly known. In a fraction of TNBCs that harbor mutations that cause the loss of function of the DNA repair-associated breast cancer type 1 susceptibility (BRCA1) gene, 1,25(OH)2D may induce protective effects by activating its receptor and inactivating cathepsin L-mediated degradation of tumor protein P53 binding protein 1 (TP53BP1), preventing deficiency in DNA double-strand break repair and contributing to genome stability. Similar effects can be induced by the interaction of 1,25(OH)2D with proteins of the growth arrest and DNA damage-inducible 45 (GADD45) family. Further studies on TNBC cell lines with exact molecular characteristics and clinical trials with well-defined cases are needed to determine the mechanism of action of vitamin D in TNBC to assess its preventive and therapeutic potential.

Nutrition, immunity and COVID-19

The immune system protects the host from pathogenic organisms (bacteria, viruses, fungi, parasites). To deal with this array of threats, the immune system has evolved to include a myriad of specialised cell types, communicating molecules and functional responses. The immune system is always active, carrying out surveillance, but its activity is enhanced if an individual becomes infected. This heightened activity is accompanied by an increased rate of metabolism, requiring energy sources, substrates for biosynthesis and regulatory molecules, which are all ultimately derived from the diet. A number of vitamins (A, B6, B12, folate, C, D and E) and trace elements (zinc, copper, selenium, iron) have been demonstrated to have key roles in supporting the human immune system and reducing risk of infections. Other essential nutrients including other vitamins and trace elements, amino acids and fatty acids are also important. Each of the nutrients named above has roles in supporting antibacterial and antiviral defence, but zinc and selenium seem to be particularly important for the latter. It would seem prudent for individuals to consume sufficient amounts of essential nutrients to support their immune system to help them deal with pathogens should they become infected. The gut microbiota plays a role in educating and regulating the immune system. Gut dysbiosis is a feature of disease including many infectious diseases and has been described in COVID-19. Dietary approaches to achieve a healthy microbiota can also benefit the immune system. Severe infection of the respiratory epithelium can lead to acute respiratory distress syndrome (ARDS), characterised by excessive and damaging host inflammation, termed a cytokine storm. This is seen in cases of severe COVID-19. There is evidence from ARDS in other settings that the cytokine storm can be controlled by n-3 fatty acids, possibly through their metabolism to specialised pro-resolving mediators.