Severe vitamin D deficiency in patients with Kawasaki disease: a potential role in the risk to develop heart vascular abnormalities?

Alterations in bile acid metabolites associated with pathogenicity and IVIG resistance in Kawasaki disease

Background

Kawasaki disease (KD) primarily affects children as an acute systemic vasculitis. Numerous studies indicated an elevated risk of cardiovascular disease due to metabolic disturbances. Despite this knowledge, the specific metabolic modes involved in KD remain unclear.

Methods

We examined the metabolome of individuals with 108 KD and 52 non-KD controls (KD vs. nKD) by ultraperformance liquid chromatography (UPLC) and tandem mass spectrometry (MS).

Results

Differential analysis uncovered the disturbed production of bile acids and lipids in KD. Furthermore, we investigated the impact of treatment, intravenous immunoglobulin (IVIG) resistance, and coronary artery (CA) occurrence on the metabolome. Our findings suggested that IVIG treatment alters the lipid and amino acid metabolism of KD patients. By orthogonal projections to latent structures discriminant analysis (OPLS-DA), there was no significant difference between the coronary injury groups and non-coronary injury groups, and IVIG resistance didn't appear to cause the metabolic change in KD patients.

Conclusions

Patients with KD exhibit metabolic abnormalities, particularly in bile acids and lipids. IVIG interventions may partially ameliorate these lipid abnormalities.

Vitamin D Deficiency Meets Hill's Criteria for Causation in SARS-CoV-2 Susceptibility, Complications, and Mortality: A Systematic Review

Clinical trials consistently demonstrate an inverse correlation between serum 25-hydroxyvitamin D [25(OH)D; calcifediol] levels and the risk of symptomatic SARS-CoV-2 disease, complications, and mortality. This systematic review (SR), guided by Bradford Hill's causality criteria, analyzed 294 peer-reviewed manuscripts published between December 2019 and November 2024, focusing on plausibility, consistency, and biological gradient. Evidence confirms that cholecalciferol (D3) and calcifediol significantly reduce symptomatic disease, complications, hospitalizations, and mortality, with optimal effects above 50 ng/mL. While vitamin D requires 3-4 days to act, calcifediol shows effects within 24 h. Among 329 trials, only 11 (3%) showed no benefit due to flawed designs. At USD 2/patient, D3 supplementation is far cheaper than hospitalization costs and more effective than standard interventions. This SR establishes a strong inverse relationship between 25(OH)D levels and SARS-CoV-2 vulnerability, meeting Hill's criteria. Vitamin D3 and calcifediol reduce infections, complications, hospitalizations, and deaths by ~50%, outperforming all patented, FDA-approved COVID-19 therapies. With over 300 trials confirming these findings, waiting for further studies is unnecessary before incorporating them into clinical protocols. Health agencies and scientific societies must recognize the significance of these results and incorporate D3 and calcifediol for prophylaxis and early treatment protocols of SARS-CoV-2 and similar viral infections. Promoting safe sun exposure and adequate vitamin D3 supplementation within communities to maintain 25(OH)D levels above 40 ng/mL (therapeutic range: 40-80 ng/mL) strengthens immune systems, reduces hospitalizations and deaths, and significantly lowers healthcare costs. When serum 25(OH)D levels exceed 70 ng/mL, taking vitamin K2 (100 µg/day or 800 µg/week) alongside vitamin D helps direct any excess calcium to bones. The recommended vitamin D dosage (approximately 70 IU/kg of body weight for a non-obese adult) to maintain 25(OH)D levels between 50-100 ng/mL is safe and cost-effective for disease prevention, ensuring optimal health outcomes.

Unveiling the Interplay-Vitamin D and ACE-2 Molecular Interactions in Mitigating Complications and Deaths from SARS-CoV-2

The interaction of the SARS-CoV-2 spike protein with membrane-bound angiotensin-converting enzyme-2 (ACE-2) receptors in epithelial cells facilitates viral entry into human cells. Despite this, ACE-2 exerts significant protective effects against coronaviruses by neutralizing viruses in circulation and mitigating inflammation. While SARS-CoV-2 reduces ACE-2 expression, vitamin D increases it, counteracting the virus's harmful effects. Vitamin D's beneficial actions are mediated through complex molecular mechanisms involving innate and adaptive immune systems. Meanwhile, vitamin D status [25(OH)D concentration] is inversely correlated with severity, complications, and mortality rates from COVID-19. This study explores mechanisms through which vitamin D inhibits SARS-CoV-2 replication, including the suppression of transcription enzymes, reduced inflammation and oxidative stress, and increased expression of neutralizing antibodies and antimicrobial peptides. Both hypovitaminosis D and SARS-CoV-2 elevate renin levels, the rate-limiting step in the renin-angiotensin-aldosterone system (RAS); it increases ACE-1 but reduces ACE-2 expression. This imbalance leads to elevated levels of the pro-inflammatory, pro-coagulatory, and vasoconstricting peptide angiotensin-II (Ang-II), leading to widespread inflammation. It also causes increased membrane permeability, allowing fluid and viruses to infiltrate soft tissues, lungs, and the vascular system. In contrast, sufficient vitamin D levels suppress renin expression, reducing RAS activity, lowering ACE-1, and increasing ACE-2 levels. ACE-2 cleaves Ang-II to generate Ang(1-7), a vasodilatory, anti-inflammatory, and anti-thrombotic peptide that mitigates oxidative stress and counteracts the harmful effects of SARS-CoV-2. Excess ACE-2 molecules spill into the bloodstream as soluble receptors, neutralizing and facilitating the destruction of the virus. These combined mechanisms reduce viral replication, load, and spread. Hence, vitamin D facilitates rapid recovery and minimizes transmission to others. Overall, vitamin D enhances the immune response and counteracts the pathological effects of SARS-CoV-2. Additionally, data suggests that widely used anti-hypertensive agents-angiotensin receptor blockers and ACE inhibitors-may lessen the adverse impacts of SARS-CoV-2, although they are less potent than vitamin D.

Exploring the association between serum Vitamin D levels and the development of coronary artery lesions in Kawasaki disease - a systematic review

BACKGROUND

Kawasaki Disease (KD) involves arterial inflammation, primarily affecting the coronary arteries and leading to coronary artery lesions. Recent advancements in understanding the immunomodulatory roles of vitamin D have prompted investigations into the potential correlation between serum vitamin D levels and the risk of coronary artery lesions (CAL) in KD. This review aims to explore this association.

METHODS

A systematic search utilizing relevant keywords related to Kawasaki disease and coronary artery lesions was conducted across four databases (PubMed, Embase, Scopus, and Web of Science). The quality of the incorporated studies was assessed utilizing the Newcastle-Ottawa Scale. The study protocol is registered in PROSPERO under the registry code CRD42024493204.

RESULTS

In a review of five studies involving 442 KD patients and 594 healthy controls, KD patients generally had lower serum vitamin D levels compared to controls, with mixed findings on the association with coronary artery lesions and IVIG resistance. While three studies supported lower vitamin D in KD, one showed no significant difference. Regarding CAL, one study found lower vitamin D, another found higher levels associated with CAL, and two found no significant difference.

CONCLUSIONS

Overall, the evidence is inconclusive, but there's a trend suggesting potential benefits of sufficient vitamin D levels in Kawasaki disease rather than evidence refuting any association with clinical outcomes.

Hypovitaminosis D and Leukocytosis to Predict Cardiovascular Abnormalities in Children with Kawasaki Disease: Insights from a Single-Center Retrospective Observational Cohort Study

Introduction: An aberrant immune response involving yet unidentified environmental and genetic factors plays a crucial role in triggering Kawasaki disease (KD). Aims: The aim of this study was to assess general and laboratory data at the onset of KD in a single-center cohort of children managed between 2003 and 2023 and retrospectively evaluate any potential relationship with the development of KD-related cardiovascular abnormalities (CVAs). Patients and methods: We took into account a total of 65 consecutive children with KD (42 males, median age: 22 months, age range: 2-88 months) followed at the Department of Life Sciences and Public Health in our University; demographic data, clinical signs, and laboratory variables at disease onset, before IVIG infusion, including C-reactive protein, hemoglobin, white blood cell (WBC) count, neutrophil count, platelet count, aminotransferases, natremia, albumin, total bilirubin, and 25-hydroxyvitamin D were evaluated. Results: Twenty-one children (32.3% of the whole cohort) were found to have echocardiographic evidence of CVAs. Univariate analysis showed that diagnosis of KD at <1 year or >5 years was associated with CVAs (p = 0.001 and p = 0.01, respectively); patients with CVAs had a longer fever duration and mostly presented atypical or incomplete presentations. Interestingly, all patients with CVAs had lower levels of vitamin D (less than 30 mg/dL, p = 0.0001) and both higher WBC and higher neutrophil counts than those without CVAs (p = 0.0001 and p = 0.01, respectively). Moreover, blood levels of albumin were significantly lower in KD patients with CVAs compared to those without (11/21, 52% versus 13/44, 30%, p = 0.02). Multiple logistic regression with correction for sex showed that serum vitamin D < 30 ng/mL, WBC count > 20.000/mm3, and age > 60 months at KD onset were the only independent factors statistically associated with CVAs. Conclusions: Hypovitaminosis D, WBC count over 20.000/mm3, and age above 5 years at KD onset emerged as independent factors statistically associated with the occurrence of CVAs.

Explorative case control study on the associations of serum vitamin D3, folic acid and vitamin B12 levels on Kawasaki disease and coronary artery lesions

Background

Kawasaki Disease (KD) is a pediatric vasculitic disorder characterized by systemic small vasculitis, notably coronary arteritis, with unclear pathogenesis. This explorative case-control study investigated the association between folic acid (FA), vitamin D3 (VD3), and vitamin B12 (VB12) levels and the different types of Kawasaki Disease, as well as the incidence of coronary artery lesions (CALs).

Methods

In this explorative case control study, 365 KD children admitted to our hospital from January 1, 2022 to June 30, 2023 were included as the KD group. Simultaneously, 365 healthy children who received physical examination during the same period were included as the control group. The KD group was divided into typical KD group and incomplete KD group (IKD group), CALs group and non-CALS group, and IVIG sensitive group and IVIG resistant group. The children with CALs were divided into small tumor group, medium tumor group and large tumor group. Serum levels of FA, VB12, and VD3 were compared across all groups.

Results

Serum levels of FA and VD3 were significantly decreased in both the KD and CALs groups (p < 0.05), and both factors were identified as independent risk factors for KD and CALs. Similarly, reduced serum VD3 levels were observed in the IKD and IVIG-resistant groups (p < 0.05), with VD3 also being an independent risk factor for both IKD and IVIG resistance. Additionally, lower serum FA levels were noted in the group with large aneurysms (p < 0.05), establishing FA as an independent risk factor for aneurysm size.

Conclusion

Serum levels of folic FA and vitamin VD3 were significantly reduced in children with KD. Furthermore, these reductions were more pronounced in children with IKD and CALs. This pattern suggests that lower FA and VD3 levels may increase the risk of more severe coronary lesions in KD patients. Therefore, monitoring these biomarkers could provide valuable insights for early clinical diagnosis and intervention.

The effect of vitamin D status on the occurrence of Kawasaki Disease: a meta-analysis

AIM

The relationship between vitamin D status and Kawasaki Disease (KD), as well as coronary artery lesion (CAL), has yet to be established.

METHODS

A meta-analysis was conducted to assess the correlation between vitamin D status and KD, as well as the impact of vitamin D status on the progression of KD into CAL.

RESULTS

The meta-analysis revealed a consistent and significant association between serum 25(OH)D level and the occurrence KD (studies N = 22; z = -3.51, P < 0.001). Patients with KD had markedly lower levels of vitamin D than healthy controls (SMD: -1.30 ng/mL, 95%CI: -2.05 to -0.55 ng/mL).

CONCLUSION

The study provided evidence supporting a significant association between lower serum vitamin D levels and the occurrence of KD, particularly within the Chinese population. However, the findings did not suggest a direct impact of vitamin D on the development of CAL in KD patients.

Investigating the comparative effect of vitamin D level with the type of complications in Henoch Schönlein purpura and Kawasaki disease

INTRODUCTION AND OBJECTIVES

Henoch Schönlein purpura (HSP) and Kawasaki disease (KD) are two main inflammatory diseases among childhood vasculitis. Considering the anti-inflammatory effects of 25-hydroxyvitamin D3, we decided to investigate the association of serum 25-hydroxy vitamin D3 level with the type and severity of these conditions.

MATERIALS AND METHODS

The present study was performed as a historical cohort of 254 affected children with KD and HSP vasculitis. The required data were extracted, using a researcher-made questionnaire from patients' electronic file, and then they were analyzed after collecting information of the patients.

RESULTS

In HSP group, 54% of participants were boys. Similarly, in KD group, boys were more affected than girls. The comparative 25-hydroxyvitamin vitamin D3 level in HSP patients with and without renal involvement (P=0.02), hematuria (P=0.14), and in two groups with and without heart disease, and also with and without coronary artery dilatation in KD patients (P<0.001) were significant.

DISCUSSION AND CONCLUSIONS

The findings showed that insufficient level of vitamin D3 were significantly associated with the exacerbation of complications of both diseases, and therefore it seems that vitamin D deficiency can be an effective predictive factor of severity in HSP and KD patients.

Infections and Autoimmunity-The Immune System and Vitamin D: A Systematic Review

Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)2D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.

Controlling Chronic Diseases and Acute Infections with Vitamin D Sufficiency

Apart from developmental disabilities, the prevalence of chronic diseases increases with age especially in those with co-morbidities: vitamin D deficiency plays a major role in it. Whether vitamin D deficiency initiates and/or aggravates chronic diseases or vice versa is unclear. It adversely affects all body systems but can be eliminated using proper doses of vitamin D supplementation and/or safe daily sun exposure. Maintaining the population serum 25(OH)D concentration above 40 ng/mL (i.e., sufficiency) ensures a sound immune system, minimizing symptomatic diseases and reducing infections and the prevalence of chronic diseases. This is the most cost-effective way to keep a population healthy and reduce healthcare costs. Vitamin D facilitates physiological functions, overcoming pathologies such as chronic inflammation and oxidative stress and maintaining broader immune functions. These are vital to overcoming chronic diseases and infections. Therefore, in addition to following essential public health and nutritional guidance, maintaining vitamin D sufficiency should be an integral part of better health, preventing acute and chronic diseases and minimize their complications. Those with severe vitamin D deficiency have the highest burdens of co-morbidities and are more vulnerable to developing complications and untimely deaths. Vitamin D adequacy improves innate and adaptive immune systems. It controls excessive inflammation and oxidative stress, generates antimicrobial peptides, and neutralizes antibodies via immune cells. Consequently, vitamin D sufficiency reduces infections and associated complications and deaths. Maintaining vitamin D sufficiency reduces chronic disease burden, illnesses, hospitalizations, and all-cause mortality. Vulnerable communities, such as ethnic minorities living in temperate countries, older people, those with co-morbidities, routine night workers, and institutionalized persons, have the highest prevalence of vitamin D deficiency-they would significantly benefit from vitamin D and targeted micronutrient supplementation. At least now, health departments, authorities, and health insurance companies should start assessing, prioritizing, and encouraging this economical, non-prescription, safe micronutrient to prevent and treat acute and chronic diseases. This approach will significantly reduce morbidity, mortality, and healthcare costs and ensure healthy aging.

Physiological Basis for Using Vitamin D to Improve Health

Vitamin D is essential for life-its sufficiency improves metabolism, hormonal release, immune functions, and maintaining health. Vitamin D deficiency increases the vulnerability and severity of type 2 diabetes, metabolic syndrome, cancer, obesity, and infections. The active enzyme that generates vitamin D [calcitriol: 1,25(OH)2D], CYP27B1 (1α-hydoxylase), and its receptors (VDRs) are distributed ubiquitously in cells. Once calcitriol binds with VDRs, the complexes are translocated to the nucleus and interact with responsive elements, up- or down-regulating the expression of over 1200 genes and modulating metabolic and physiological functions. Administration of vitamin D3 or correct metabolites at proper doses and frequency for longer periods would achieve the intended benefits. While various tissues have different thresholds for 25(OH)D concentrations, levels above 50 ng/mL are necessary to mitigate conditions such as infections/sepsis, cancer, and reduce premature deaths. Cholecalciferol (D3) (not its metabolites) should be used to correct vitamin D deficiency and raise serum 25(OH)D to the target concentration. In contrast, calcifediol [25(OH)D] raises serum 25(OH)D concentrations rapidly and is the agent of choice in emergencies such as infections, for those who are in ICUs, and for insufficient hepatic 25-hydroxylase (CYP2R1) activity. In contrast, calcitriol is necessary to maintain serum-ionized calcium concentration in persons with advanced renal failure and hypoparathyroidism. Calcitriol is, however, ineffective in most other conditions, including infections, and as vitamin D replacement therapy. Considering the high costs and higher incidence of adverse effects due to narrow therapeutic margins (ED50), 1α-vitamin D analogs, such as 1α-(OH)D and 1,25(OH)2D, should not be used for other conditions. Calcifediol analogs cost 20 times more than D3-thus, they are not indicated as a routine vitamin D supplement for hypovitaminosis D, osteoporosis, or renal failure. Healthcare workers should resist accepting inappropriate promotions, such as calcifediol for chronic renal failure and calcitriol for osteoporosis or infections-there is no physiological rationale for doing so. Maintaining the population's vitamin D sufficiency (above 40 ng/mL) with vitamin D3 supplements and/or daily sun exposure is the most cost-effective way to reduce chronic diseases and sepsis, overcome viral epidemics and pandemics, and reduce healthcare costs. Furthermore, vitamin D sufficiency improves overall health (hence reducing absenteeism), reduces the severity of chronic diseases such as metabolic and cardiovascular diseases and cancer, decreases all-cause mortality, and minimizes infection-related complications such as sepsis and COVID-19-related hospitalizations and deaths. Properly using vitamin D is the most cost-effective way to reduce chronic illnesses and healthcare costs: thus, it should be a part of routine clinical care.

COVID-19 infection and metabolic comorbidities: Mitigating role of nutritional sufficiency and drug - nutraceutical combinations of vitamin D

The vulnerability of human health is amplified in recent times with global increase in non-communicable diseases (due to lifestyle changes and environmental insults) and infectious diseases (caused by newer pathogens and drug-resistance strains). Clinical management of diseases is further complicated by disease severity caused by other comorbid factors. Drug-based therapy may not be the sole approach, particularly in scenarios like the COVID-19 pandemic, where there is no specific drug against SARS-CoV-2. Nutritional interventions are significant in armouring human populations in disease prevention, and as adjunctive therapy for disease alleviation. Amidst ongoing clinical trials to determine the efficacy of Vit. D against infections and associated complications, this review examines the pleiotropic benefits of nutritional adequacy of vitamin D (Vit. D) in combating viral infections (COVID-19), its severity and complications due to co-morbidities (obesity, diabetes, stroke and Kawasaki disease), based on research findings and clinical studies. Supplements of Vit. D in combination with other nutrients, and drugs, are suggested as promising preventive-health and adjunct-treatment strategies in the clinical management of viral infections with metabolic comorbidities.

Serum Vitamin D Levels in Relation to Development of Multisystem Inflammatory Syndrome in Pediatric COVID-19

Objective The aim of the study is to evaluate vitamin D (vit D) levels in children with and without development of multisystem inflammatory syndrome in children (MIS-C) after coronavirus disease 2019 (COVID-19) and also between those with severe and moderate MIS-C.

Methods This comprises retrospective data of 68 patients including 34 patients with MIS-C and admitted into the pediatric intensive care unit (MIS-C group) and 34 patients without MIS-C (non-MIS-C group) were analyzed for their presenting characteristics, serum vit D levels, ventilatory needs, and prognostic scores.

Results Vit D levels were significantly lower in patients with versus without MIS-C [9 (2–18) vs. 19 (10–43) ng/mL, p <0.001], and also in patients with severe versus moderate MIS-C [7.5 (2–17) vs. 9 (5–18) ng/mL, p = 0.024]. Vit D deficiency (levels <12 ng/mL) was more common in the MIS-C versus non-MIS-C group (79.4 vs. 11.8%, p <0.001) and in severe versus moderate MIS-C (92.9 vs. 70.0%, p <0.001). The severe versus moderate MIS-C was associated with significantly higher levels of procalcitonin [7.6 (0.9–82) vs. 1.7 (0.2–42) ng/mL, p = 0.030] and troponin [211 (4.8–4,545) vs. 14.2 (2.4–3,065) ng/L, p = 0.008] and higher likelihood of reduced ejection fraction (75.0 vs. 15.4%, p = 0.004).

Conclusion Our findings indicate the higher prevalence of vit D deficiency in pediatric COVID-19 patients with versus without MIS-C, as well as in those with severe versus moderate MIS-C. Higher troponin and procalcitonin levels and dyspnea at presentation seem also to be risk factors for severe MIS-C, more pronounced cardiac dysfunction, and poorer prognosis.

The Effect of Vitamin D Levels in Multisystem Inflammatory Syndrome in Children

Objective Multiple factors being overweight, asthmatic, or being of Asian or black ethnic origins have been reported vis-à-vis the “multisystem inflammatory syndrome in children” (MIS-C). There is an association between these conditions and vitamin D deficiency, which explains why MIS-C is more common in these patients. In the present study, we attempted to retrospective evaluate the 25-hydroxy vitamin D levels of patients with MIS-C, its association with acute phase reactants, its treatment, and clinical status.

Methods Patients aged between 1.5 months to 18 years with MIS-C were included in the study. All of the laboratory parameters, treatment, and response to the treatment were evaluated retrospectively. Two groups were formed. Patients had 25‐hydroxycholecalciferol D vitamin < 20 ng/mL in group 1 and ≥ 20 ng/mL in group 2.

Results A total of 52 patients were included in the study. There was no statistical difference between groups in terms of acceptance of the intensive care unit treatment (p = 0.29) and response to the first-line treatment (p = 0.56). A lower median lymphocyte count (p = 0.01) and a higher median C-reactive protein (p = 0.04) and procalcitonin (p = 0.01) with N-terminal pro-B-type natriuretic peptide (p = 0.025) values were found in group 1.

Conclusion Vitamin D deficiency was associated with an increased inflammatory response in children with MIS-C. More studies are required to determine the potential impact of vitamin D deficiency on the clinical outcome of MIS-C.

The impact of vitamin D on the onset and progress of Kawasaki disease

BACKGROUND

The seasonal epidemic of Kawasaki disease (KD) in winter in Japan suggests that low vitamin D status may affect KD through the immune system. We aimed to evaluate the effect of vitamin D on the onset and clinical course of KD.

METHODS

We conducted a case-control study to compare 25-hydroxyvitamin D (25(OH)D) levels in KD patients admitted to our hospital between March 2018 and June 2021, with those in healthy controls from published Japanese data. In patients with KD, we evaluated the association of 25(OH)D levels with intravenous immunoglobulin resistance and coronary artery lesions.

RESULTS

We compared 290 controls and 86 age-group-adjusted patients with KD. The 25(OH)D levels in KD patients were lower than those in the controls (median: 17 vs. 29 ng/mL, P < 0.001). In winter, 25(OH)D levels in KD patients were lower than those in summer (median: 13 vs. 19 ng/mL). The adjusted odds ratios for the onset of KD were 4.9 (95% CI: 2.5-9.6) for vitamin D insufficiency (25(OH)D: 12-20 ng/mL) and 29.4 (95% CI: 12.5-78.2) for vitamin D deficiency (25(OH)D < 12 ng/mL). Among 110 KD patients, 25(OH)D levels at diagnosis of KD were not associated with intravenous immunoglobulin resistance or coronary artery lesions.

CONCLUSIONS

The 25(OH)D levels in patients with KD were lower than those in the controls, especially in winter. Lower 25(OH)D levels in winter were associated with an increased risk of KD onset. It remains to be elucidated whether the observed association has a causal relationship.

The immune landscape of SARS-CoV-2-associated Multisystem Inflammatory Syndrome in Children (MIS-C) from acute disease to recovery

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening disease occurring several weeks after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Deep immune profiling showed acute MIS-C patients had highly activated neutrophils, classical monocytes and memory CD8+ T-cells, with increased frequencies of B-cell plasmablasts and double-negative B-cells. Post treatment samples from the same patients, taken during symptom resolution, identified recovery-associated immune features including increased monocyte CD163 levels, emergence of a new population of immature neutrophils and, in some patients, transiently increased plasma arginase. Plasma profiling identified multiple features shared by MIS-C, Kawasaki Disease and COVID-19 and that therapeutic inhibition of IL-6 may be preferable to IL-1 or TNF-α. We identified several potential mechanisms of action for IVIG, the most commonly used drug to treat MIS-C. Finally, we showed systemic complement activation with high plasma C5b-9 levels is common in MIS-C suggesting complement inhibitors could be used to treat the disease.

Multisystem inflammatory syndrome in children and Kawasaki disease: a critical comparison

Children and adolescents infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are predominantly asymptomatic or have mild symptoms compared with the more severe coronavirus disease 2019 (COVID-19) described in adults. However, SARS-CoV-2 is also associated with a widely reported but poorly understood paediatric systemic vasculitis. This multisystem inflammatory syndrome in children (MIS-C) has features that overlap with myocarditis, toxic-shock syndrome and Kawasaki disease. Current evidence indicates that MIS-C is the result of an exaggerated innate and adaptive immune response, characterized by a cytokine storm, and that it is triggered by prior SARS-CoV-2 exposure. Epidemiological, clinical and immunological differences classify MIS-C as being distinct from Kawasaki disease. Differences include the age range, and the geographical and ethnic distribution of patients. MIS-C is associated with prominent gastrointestinal and cardiovascular system involvement, admission to intensive care unit, neutrophilia, lymphopenia, high levels of IFNγ and low counts of naive CD4⁺ T cells, with a high proportion of activated memory T cells. Further investigation of MIS-C will continue to enhance our understanding of similar conditions associated with a cytokine storm.

Shedding light on vitamin D: the shared mechanistic and pathophysiological role between hypovitaminosis D and COVID-19 risk factors and complications

Severe acute respiratory syndrome coronavirus (SARS-COV-2) is the culprit of the Coronavirus Disease (COVID-19), which has infected approximately 173 million people and killed more than 3.73 million. At risk groups including diabetic and obese patients are more vulnerable to COVID-19-related complications and poor outcomes. Substantial evidence points to hypovitaminosis D as a risk factor for severe disease, the need for ICU, and mortality. 1,25(OH)D, a key regulator of calcium homeostasis, is believed to have various immune-regulatory roles including; promoting anti-inflammatory cytokines, down regulating pro-inflammatory cytokines, dampening entry and replication of SARS-COV-2, and the production of antimicrobial peptides. In addition, there are strong connections which suggest that dysregulated 1,25(OH)D levels play a mechanistic and pathophysiologic role in several disease processes that are shared with COVID-19 including: diabetes, obesity, acute respiratory distress syndrome (ARDS), cytokine storm, and even hypercoagulable states. With evidence continuing to grow for the case that low vitamin D status is a risk factor for COVID-19 disease and poor outcomes, there is a need now to address the public health efforts set in place to minimize infection, such as lock down orders, which may have inadvertently increased hypovitaminosis D in the general population and those already at risk (elderly, obese, and disabled). Moreover, there is a need to address the implications of this evidence and how we may apply the use of cheaply available supplementation, which has yet to overcome the near global concern of hypovitaminosis D. In our review, we exhaustively scope these shared pathophysiologic connections between COVID-19 and hypovitaminosis D.

The effect of vitamin D3 and thyroid hormones on the capillaroscopy-confirmed microangiopathy in pediatric patients with a suspicion of systemic connective tissue disease-a single-center experience with Raynaud phenomenon

Raynaud phenomenon (RP) may be the first manifestation of a systemic connective tissue disease (SCTD). Early detection of dysfunction of small vessels called microangiopathy is essential for the diagnostic process. The focus of this single-center, retrospective study was to investigate the potential dependencies between microvascular image and laboratory markers measured in children with RP. The study analyzed the nail-fold video-capillaroscopy (NVC) findings and laboratory results of 81 children between the ages 6 and 17 who were referred to pediatric rheumatologist with a suspicion of SCTD. Out of 52 patients presenting with RP at the time of evaluation, abnormalities in capillary microscopic imaging were found in 34. NVC findings were then compared to levels of specific biomarkers in serum. Vitamin D3 serum levels have been significantly decreased in patients with RP (23.4 ng/mL ± 8.76 vs. 30.0 ng/mL ± 12.66, P = 0.0148). There were positive significant correlations between levels of vitamin D3 and acute-phase reactants in serum, such as C-reactive protein (P = 0.0292). Furthermore, free thyroxine levels (fT4) in patients with both RP (P = 0.0126) and micro-angiopathy (P = 0.05496) persisted in the lower range of the normal limit (< 1.0 ng/dL). Regular oral supplementation of vitamin D3 should be always considered in children with RP if deficiency is found. Additionally, low fT4 level (< 1.0 ng/dL) should be considered as an indication to perform NVC in patients suspected of SCTD even when they do not present RP.

Vitamin D status of children with Paediatric Inflammatory Multisystem Syndrome Temporally associated with Severe acute respiratory syndrome coronavirus 2 (PIMS-TS)

Coronavirus disease 2019 (COVID-19) has caused mild illness in children, until the emergence of the novel hyperinflammatory condition paediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PIMS-TS). PIMS-TS is thought to be a post-SARS-CoV-2 immune dysregulation with excessive inflammatory cytokine release. We studied 25 hydroxyvitamin D (25OHD) concentrations in children with PIMS-TS, admitted to a tertiary paediatric hospital in the UK, due to its postulated role in cytokine regulation and immune response. Eighteen children (median (range) age 8·9 (0·3-14·6) years, male = 10) met the case definition. The majority were of Black, Asian and Minority Ethnic (BAME) origin (89 %, 16/18). Positive SARS-CoV-2 IgG antibodies were present in 94 % (17/18) and RNA by PCR in 6 % (1/18). Seventy-eight percentage of the cohort were vitamin D deficient (< 30 nmol/l). The mean 25OHD concentration was significantly lower when compared with the population mean from the 2015/16 National Diet and Nutrition Survey (children aged 4–10 years) (24 v. 54 nmol/l (95 % CI −38·6, −19·7); P < 0·001). The paediatric intensive care unit (PICU) group had lower mean 25OHD concentrations compared with the non-PICU group, but this was not statistically significant (19·5 v. 31·9 nmol/l; P = 0·11). The higher susceptibility of BAME children to PIMS-TS and also vitamin D deficiency merits contemplation. Whilst any link between vitamin D deficiency and the severity of COVID-19 and related conditions including PIMS-TS requires further evidence, public health measures to improve vitamin D status of the UK BAME population have been long overdue.

Vitamin D in Corona Virus Disease 2019 (COVID-19) Related Multisystem Inflammatory Syndrome in Children (MIS-C)

Multisystem Inflammatory Syndrome in children (MIS-C) is a rare but devastating complication of coronavirus disease 19 (COVID-19). The development of prognostic biomarkers and more importantly the implementation of new treatment modalities would have a significant impact in clinical practice regarding the outcome of MIS-C. Vitamin D could be a potential candidate. In this mini review we analyze the immunomodulatory role of vitamin D in viral infections and specifically in COVID-19. We also examine the current literature regarding the association of vitamin D with MIS-C and Kawasaki disease. The vitamin D was evaluated not only as a biomarker but also as a nutritional supplement. We concluded that vitamin D levels could be valuable in predicting severe forms of MIS-C and correction of abnormal levels in severe MIS-C may influences its evolution. 25-hydroxyvitamin D3 [25(OH)D3] supplementation raising serum [25(OH)D] concentrations potentially have a favorable effect in reducing the severity of MIS-C in certain circumstances. Further studies are needed to confirm these results.

Phenotype, Susceptibility, Autoimmunity, and Immunotherapy Between Kawasaki Disease and Coronavirus Disease-19 Associated Multisystem Inflammatory Syndrome in Children

Coronavirus disease-19 (COVID-19) in children is usually mild but some are susceptible to a Kawasaki disease (KD)-like multisystem inflammatory syndrome in children (MIS-C) in the convalescent stage, posing a need to differentiate the phenotype, susceptibility, autoimmunity, and immunotherapy between KD and MIS-C, particularly in the upcoming mass vaccination of COVID-19. Patients with MIS-C are prone to gastrointestinal symptoms, coagulopathy, and shock in addition to atypical KD syndrome with fever, mucocutaneous lesions, lymphadenopathy, and/or cardiovascular events. MIS-C manifests KD-like symptoms that alert physicians to early recognize and adopt the KD treatment regimen for patients with MIS-C. MIS-C linked to COVID-19 teaches us infection-associated autoimmune vasculitis and vice versa. Studies on genetic susceptibility have identified certain human leukocyte antigen (HLA) locus and toll-like receptor (TLR) associated with KD and/or COVID-19. Certain HLA subtypes, such as HLA-DRB1 and HLA-MICA A4 are associated with KD. HLA-B*46:01 is proposed to be the risk allele of severe COVID-19 infection, and blood group O type is a protective factor of COVID-19. The autoimmune vasculitis of KD, KD shock syndrome (KDSS), or MIS-C is mediated by a genetic variant of HLA, FcγR, and/or antibody-dependent enhancement (ADE) resulting in hyperinflammation with T helper 17 (Th17)/Treg imbalance with augmented Th17/Th1 mediators: interleukin-6 (IL-6), IL-10, inducible protein-10 (IP-10), Interferon (IFNγ), and IL-17A, and lower expression of Treg-signaling molecules, FoxP3, and transforming growth factor (TGF-β). There are certain similarities and differences in phenotypes, susceptibility, and pathogenesis of KD, KDSS, and MIS-C, by which a physician can make early protection, prevention, and precision treatment of the diseases. The evolution of immunotherapies for the diseases has shown that intravenous immunoglobulin (IVIG) alone or combined with corticosteroids is the standard treatment for KD, KDSS, and MIS-C. However, a certain portion of patients who revealed a treatment resistance to IVIG or IVIG plus corticosteroids, posing a need to early identify the immunopathogenesis, to protect hosts with genetic susceptibility, and to combat Th17/Treg imbalance by anti-cytokine or pro-Treg for reversal of the hyperinflammation and IVIG resistance. Based on physiological and pathological immunity of the diseases under genetic susceptibility and host milieu conditions, a series of sequential regimens are provided to develop a so-called "Know thyself, enemy (pathogen), and ever-victorious" strategy for the prevention and immunotherapy of KD and/or MIS-C.

Possible role of vitamin D in Covid-19 infection in pediatric population

PURPOSE

Covid-19 is a pandemic of unprecedented proportion, whose understanding and management is still under way. In the emergency setting new or available therapies to contrast the spread of COVID-19 are urgently needed. Elderly males, especially those affected by previous diseases or with comorbidities, are more prone to develop interstitial pneumonia that can deteriorate evolving to ARDS (acute respiratory distress syndrome) that require hospitalization in Intensive Care Units (ICUs). Even children and young patients are not spared by SARS-CoV 2 infection, yet they seem to develop a milder form of disease. In this setting the immunomodulatory role of Vitamin D, should be further investigated.

METHODS

We reviewed the literature about the immunomodulatory role of Vitamin D collecting data from the databases Medline and Embase.

RESULTS

Vitamin D proved to interact both with the innate immune system, by activating Toll-like receptors (TLRs) or increasing the levels of cathelicidins and β-defensins, and adaptive immune system, by reducing immunoglobulin secretion by plasma cells and pro-inflammatory cytokines production, thus modulating T cells function. Promising results have been extensively described as regards the supplementation of vitamin D in respiratory tract infections, autoimmune diseases and even pulmonary fibrosis.

CONCLUSIONS

In this review, we suggest that vitamin D supplementation might play a role in the prevention and/or treatment to SARS-CoV-2 infection disease, by modulating the immune response to the virus both in the adult and pediatric population.

Perspective of Immunopathogenesis and Immunotherapies for Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory illness that mostly occurs in children below 5 years of age, with intractable fever, mucocutaneous lesions, lymphadenopathy, and lesions of the coronary artery (CAL). KD is sharing clinical symptoms with systemic inflammatory syndrome in children (MIS-C) which is related to COVID-19. Certain genes are identified to be associated with KD, but the findings usually differ between countries and races. Human Leukocyte Antigen (HLA) allele types and toll-like receptor (TLR) expression are also correlated to KD. The acute hyperinflammation in KD is mediated by an imbalance between augmented T helper 17 (Th17)/Th1 responses with high levels of interleukin (IL)-6, IL-10, IL-17A, IFN-γ, and IP-10, in contrast to reduced Th2/Treg responses with lower IL-4, IL-5, FoxP3, and TGF-β expression. KD has varying phenotypic variations regarding age, gender, intravenous immunoglobulin (IVIG) resistance, macrophage activation and shock syndrome. The signs of macrophage activation syndrome (MAS) can be interpreted as hyperferritinemia and thrombocytopenia contradictory to thrombocytosis in typical KD; the signs of KD with shock syndrome (KDSS) can be interpreted as overproduction of nitric oxide (NO) and coagulopathy. For over five decades, IVIG and aspirin are the standard treatment for KD. However, some KD patients are refractory to IVIG required additional medications against inflammation. Further studies are proposed to delineate the immunopathogenesis of IVIG-resistance and KDSS, to identify high risk patients with genetic susceptibility, and to develop an ideal treatment regimen, such as by providing idiotypic immunoglobulins to curb cytokine storms, NO overproduction, and the epigenetic induction of Treg function.

Kawasaki-like diseases and thrombotic coagulopathy in COVID-19: delayed over-activation of the STING pathway?

We previously made the hypothesis that STING contributes to COVID-19. The present review detail new arguments for over-activation of STING pathways in COVID-19, following the description of hyper-coagulability and Kawasaki-like diseases in children. Indeed, Kawasaki disease is induced by overreaction of innate cells following exposition to various viruses, including herpes viruses which trigger STING. It predisposes to diffuse vasculitis and aneurysms, whereas STING is over-expressed in arterial aneurisms. The redness at the inoculation site of bacillus Calmette-Guérin, a specific feature of Kawasaki disease, is reproduced by activation of the STING pathway, which is inhibited upstream by aspirin, intravenous immunoglobulins, and Vitamin-D. SARS-CoV2 binding to ACE2 can lead to excessive angiotensin II signaling, which activates the STING pathway in mice. Over-activation of the STING-pathway promotes hyper-coagulability through release of interferon-β and tissue factor by monocytes-macrophages. Aspirin and dipyridamole, besides their anti-platelet activity, also reduce tissue factor procoagulant activity, and aspirin inhibits the STING pathway upstream of STING. Aspirin and dipyridamole may be used, in combination with drugs blocking downstream the activation of the STING pathway, like inhibitors of IL-6R and JAK/STAT pathways. The risk of bleeding should be low as bleeding has not been reported in severe COVID-19 patients.

Is vitamin D deficiency a risk factor for COVID-19 in children?

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is a global health problem that can result in serious complications. The aim of this study was to investigate the prevalence and clinical importance of vitamin D deficiency in children with COVID-19.

MATERIAL AND METHODS

This study includes 40 patients who were diagnosed to have COVID-19 and hospitalized with the real-time reverse transcription polymerase chain reaction method, 45 healthy matched control subjects with vitamin D levels. The age of admission, clinical and laboratory data, and 25-hydroxycholecalciferol (25-OHD) levels were recorded. Those with vitamin D levels which are below 20 ng/ml were determined as Group 1 and those with ≥20 ng/ml as Group 2.

RESULTS

Patients with COVID-19 had significantly lower vitamin D levels 13.14 μg/L (4.19-69.28) than did the controls 34.81 (3.8-77.42) μg/L (p < .001). Patients with COVID-19 also had significantly lower serum phosphorus (4.09 ± 0.73 vs. 5.06 ± 0.93 vs. (U/L) (p < .001)) values compared with the controls. The symptom of fever was significantly higher in COVID- 19 patients who had deficient and insufficient vitamin D levels than in patients who had sufficient vitamin D levels (p = .038). There was a negative correlation found between fever symptom and vitamin D level (r = -0.358, p = .023).

CONCLUSION

This is the first to evaluate vitamin D levels and its relationship with clinical findings in pediatric patients with COVID-19. Our results suggest that vitamin D values may be associated with the occurrence and management of the COVID-19 disease by modulating the immunological mechanism to the virus in the pediatric population.

Evidence for possible association of vitamin D status with cytokine storm and unregulated inflammation in COVID-19 patients

OBJECTIVES

We present evidence for a possible role of Vitamin D (VitD) deficiency in unregulated cytokine production and inflammation leading to complications in COVID-19 patients.

DESIGN

The time-adjusted case mortality ratio (T-CMR) was estimated as the ratio of deceased patients on day N to the confirmed cases on day N-8. The adaptive average of T-CMR (A-CMR) was calculated as a metric of COVID-19 associated mortality. A model based on positivity change (PC) and an estimated prevalence of COVID-19 was used to determine countries with similar screening strategies. A possible association of A-CMR with the mean concentration of 25-hydroxyvitamin D (25(OH)D) in elderly individuals in countries with similar screening strategy was investigated. We considered high C-reactive protein (CRP) in severe COVID-19 patients (CRP ≥ 1 mg/dL) as a surrogate of a cytokine storm. We considered high-sensitivity CRP (hs-CRP) in healthy subjects as hs-CRP ≥ 0.2 mg/dL.

RESULTS

A link between 25(OH)D and A-CMR in countries with similar screening strategy is evidence for VitD's possible role in reducing unregulated cytokine production and inflammation among patients with severe COVID-19. We observed an odds ratio (OR) of 1.8 with 95% confidence interval (95% CI) (1.2 to 2.6) and an OR of 1.9 with 95% CI (1.4 to 2.7) for hs-CRP in VitD deficient elderly from low-income families and high-income families, respectively. COVID-19 patient-level data show an OR of 3.4 with 95% CI (2.15 to 5.4) for high CRP in severe COVID-19 patients.

CONCLUSION

We conclude that future studies on VitD's role in reducing cytokine storm and COVID-19 mortality are warranted.

Letter: low population mortality from COVID-19 in countries south of latitude 35° North supports vitamin D as a factor determining severity. Authors' reply

LINKED CONTENT This article is linked to Rhodes et al and Mansur papers. To view these articles, visit https://doi.org/10.1111/apt.15777 and https://doi.org/10.1111/apt.15820.

Vitamin D and Cardiovascular Risk: which Implications in Children?

Vitamin D (25OHD) pleiotropic effects are widely recognized and studied. Recently, vitamin D cardiovascular effects are gaining interest, especially in children, although the studies present conflicting data. Some randomized controlled trials (RCTs) have demonstrated that cardiovascular risk markers, such as lipid parameters, inflammation markers, blood pressure, and arterial stiffness, are unaffected by vitamin D supplementation. By contrast, other studies show that low vitamin D levels are associated with higher risk of cardiovascular disease (CVD) and mortality, and support that increased risk of these diseases occurs primarily in people with vitamin D deficiency. An update on these points in pediatric patients is certainly of interest to focus on possible benefits of its supplementation.

Increased concentrations of growth differentiation factor-15 in children with Kawasaki disease

BACKGROUND

We investigated the serum concentrations of growth differentiation factor-15 (GDF-15) in children with acute Kawasaki disease (KD) and evaluate its role in predicting coronary artery lesions (CALs) and no response KD.

METHODS

We obtained blood sample from 30 healthy children and 131 children with KD before intravenous immunoglobulin therapy. Serum GDF-15 concentrations were measured using ELISA kits. Univariate and multivariate logistic regression analysis were conducted to evaluate the potential association between GDF-15 and the occurrence of CALs and treatment responses.

RESULTS

Serum GDF-15 concentrations in KD were remarkably increased compared with healthy control. Serum GDF-15 concentrations in KD with CALs were also increased compared with no CALs, and in no response KD compared with response KD. Serum of GDF-15 concentrations was positively correlated with white blood cell count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and negatively associated with albumin and pre-albumin in all patients with KD. GDF-15 was an independent predictor of CALs and no response KD. GDF-15 was superior to CRP and ESR, while it was not inferior to the combination of CRP and ESR for predicting CALs.

CONCLUSIONS

Serum of GDF-15 concentrations was significantly increased in acute KD patients, especially in KD with CALs and no response KD. GDF-15 could sever as an independent predictor for CALs and no response KD.

Breastfeeding and vitamin D supplementation reduce the risk of Kawasaki disease in a German population-based case-control study

Background

In Kawasaki disease (KD), a vasculitis of unknown etiology, the most serious complication is the development of coronary artery aneurysm (CAA). To date, the exact pathomechanism of KD is unknown. Both environmental and genetic factors seem to be associated with the development of the disease.

Methods

Data on KD patients recruited from the population-based German Pediatric Surveillance Study during 2012–2014 were used to evaluate the impact of various factors from the perinatal and infancy period on the development of KD. The study design was a matched case-control study with respect to age, sex and place of residence (n = 308 KD cases, n = 326 controls). All KD patients were individually re-evaluated; all fulfilled the international diagnostic KD criteria. A standardized questionnaire was used to review breastfeeding practices, vitamin D supplementation and birth characteristics. Logistic regression analyses were performed to obtain odds ratios (OR) for various risk factors among the case-control pairs. Simple measures of association were used to assess the impact of these factors on the clinical course.

Results

There was no difference in lengths of gestation, birth weight or parturition between KD patients and controls, but independently from each other vitamin D supplementation and breastfeeding were negatively associated with KD, even when adjusted for age, place of residence and sex. The duration of vitamin D was significantly shorter among children with KD than among children without KD (p = 0.039, OR = 0.964, 95% CI: 0.931–0.998), as was the duration of breastfeeding (p = 0.013, OR = 0.471, 95% CI: 0.260–0.853). Comparing KD patients with and without breastfeeding and/or vitamin D supplementation, there were no differences regarding developing CAA, being refractory to intravenous immunoglobulin treatment, age at onset of the disease and levels of inflammatory laboratory values.

Conclusion

Our findings indicate breastfeeding and vitamin D supplementation to have protective effects in association with KD in our study population; however, these seem not to influence the natural course of the disease. Although the overall effects were relatively small, they nevertheless underline the overall benefit of both interventions.

Trial registration

Clinical Trial Registration: German clinical trial registration, http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010071. Date of registration was 26. February 2016. The trial was registered retrospectively.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1438-2) contains supplementary material, which is available to authorized users.

Vitamin D and Cardiovascular Risk in Children

OBJECTIVE

Vitamin D is a group of fat-soluble molecules that are structurally similar to steroids. Emerging data have led to the hypothesis that Vitamin D plays a role in the regulation of many physiological processes beyond calcium and phosphorus homeostasis. With this review, we aimed to summarize the changes in Vitamin D levels in children with cardiovascular diseases based on the literature. In addition, we also reviewed the potential mechanisms underlying cardiovascular diseases associated with Vitamin D deficiency or insufficiency.

DATA SOURCES

The articles in English were searched from PubMed (1968-2016) and EMBASE (1991-2016), with the keywords of "Vitamin D AND cardiovascular diseases" and "Vitamin D AND children."

STUDY SELECTION

Original articles and critical reviews about Vitamin D and cardiovascular risk in children were selected for review. Researches focused on adults were excluded.

RESULTS

Studies have shown that several pediatric cardiovascular diseases may be associated with Vitamin D deficiency or insufficiency, including hypertension, orthostatic intolerance, and Kawasaki disease.

CONCLUSIONS

Vitamin D may play a role in the regulation of the cardiovascular system. Further investigation would hopefully disclose the usefulness of Vitamin D as a biomarker for cardiovascular diseases in children.

Relationship between vitamin D levels and intravenous immunoglobulin resistance in Kawasaki disease

Purpose

Vitamin D is associated with various pathological conditions such as cardiovascular diseases and cancer. We investigated the relationship between vitamin D and Kawasaki disease (KD).

Methods

We performed a retrospective review of the medical records of patients with KD between February 2013 and March 2016 in Daegu Fatima Hospital. Study participants were grouped according to vitamin D serum concentration. Group 1 included patients with 25(OH)-vitamin D ≥20 ng/mL. Group 2 included patients with 25(OH)-vitamin D <20 ng/mL. We analyzed the clinical characteristics and laboratory data of the 2 groups.

Results

Of the 91 patients, 52 were included in group 1, and 39 in group 2. Group 1 patients had significantly higher levels of calcium, phosphate, albumin and sodium than group 2 patients did. There were no differences in clinical characteristics, but the proportion of patients with polymorphic rash was significantly higher in group 2. Resistance to intravenous immunoglobulin was more frequent in group 2 (P=0.023). No significant difference in the incidence of coronary artery complications was observed.

Conclusion

Low vitamin D levels are associated with resistance to intravenous immunoglobulin therapy in KD. Vitamin D deficiency might be a risk factor for immunoglobulin resistance in KD.

[Research advances in association between vitamin D and Kawasaki disease and related mechanisms of action]

Vitamin D is an important steroid hormone, which has a wide biological effect and is the protective factor against cardiovascular disease and other diseases. At present, the etiology and pathogenesis of Kawasaki disease (KD) remain unknown, but recent studies have shown that vitamin D insufficiency or deficiency is associated with KD. Vitamin D insufficiency or deficiency may affect KD via its influence on inflammatory response, adipokine, endothelial function, platelet function, and DNA methylation and increase the risk of coronary artery lesions. This article reviews the research advances in the association between vitamin D and KD and possible mechanisms of action.

Vitamin D nutritional status and the risk for cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality. CVD has a significant impact on health care systems worldwide and over 23 million individuals are expected to succumb to the disease by 2030. Early onset of atherosclerosis in childhood along with other risk factors of CVD, including elevated circulating lipids, have been shown to persist in adulthood and lead to CVD. Vitamin D deficiency is considered a risk factor for the pathogenesis of CVD, with childhood nutritional status of vitamin D being an important determinant of the development of CVD. Low levels of 25-hydroxyvitamin D can arise due to reduced intake as well as geographical location, and other diseases/conditions such as chronic kidney disease and obesity. Childhood vitamin D deficiency can progress and lead to atherosclerosis and other CVDs in adulthood. Early intervention with vitamin D supplementation is an ideal approach towards preventive therapy. However, there is no clear consensus regarding the role of vitamin D in childhood CVD. In the present study, we reviewed the available evidence in favor of and against such a role for this vitamin.