Serum 25-hydroxyvitamin D and IgE - a significant but nonlinear relationship

Associations between serum 25-hydroxyvitamin D and prognosis of chronic kidney disease: a prospective cohort study

BACKGROUND AND OBJECTIVES

25-hydroxyvitamin D [25(OH)D] deficiency is prevalent in patients with chronic kidney disease (CKD), the associations between serum 25(OH)D levels and mortality in patients with CKD remain unclear, and this study aimed to explore these associations further.

METHODS

4989 participants with CKD were enrolled in the study, and the Cox regression model was used to assess the effects of serum 25(OH)D concentrations on mortality risk. A restricted cubic spline model was used to explore the dose-response relationships, and threshold effect analysis was performed based on inflection points identified by a two-piecewise linear regression model. In addition, subgroup and sensitivity analyses were employed.

RESULTS

1255 participants died during a mean follow-up period of 70 months. Compared with the 25(OH)D-deficient group, the fully adjusted hazard ratios and 95% confidence intervals for the 25(OH)D-adequate group were 0.631 (0.545, 0.730) for all-cause mortality, 0.569 (0.435, 0.743) for cardiovascular mortality, 0.637 (0.461, 0.878) for hypertension mortality, and cancer mortality was 0.596 (0.426, 0.834). The inflection points of serum 25(OH)D concentration affecting all-cause and cardiovascular mortality were 89 nmol/L, and 107 nmol/L, respectively. Subgroup analyses and interaction tests suggested that the effects varied across populations. The results of sensitivity analyses indicated a reliable correlation.

CONCLUSION

We found an association between serum 25(OH)D concentrations and the prognosis of patients with CKD as a reliable predictor of early intervention and intensive care.

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.

Genetic variants in the vitamin D pathway and their association with vitamin D metabolite levels: Detailed studies of an inner-city pediatric population suggest a modest but significant effect in early childhood

OBJECTIVES

In a large cohort of healthy infants and toddlers 6-36 months of age (n = 776), we have been exploring the potential role of genetic variation in predisposition to vitamin D insufficiency. The genes encoding the key cytochrome P450 hydroxylases (CYP2R1, CYP24A1, and CYP27B1) harbour recurrent mutations of uncertain effect. This study was undertaken to look for biochemically relevant associations of these variants with inter-individual differences in vitamin D metabolism in an at-risk pediatric population.

METHODS

Genotyping for CYP2R1-CT (c.-1127 C>T, rs10741657), CYP24A1-AG (c.-686A>G, rs111622401), and CYP27B1-CA (c.-1261 C>A, rs10877012) mutations were performed using SNaPshot assay, followed by Sanger sequencing confirmation. Vitamin D metabolites and vitamin D binding protein (DBP) were measured by established methods.

RESULTS

In a multivariate regression model, with corrections for co-variates, subjects with the homozygous CYP2R1-TT variant had significantly higher concentrations of 25(OH)D, free 25(OH)D, and 24,25(OH)2D levels. In subjects with the CYP24A1-AG mutation, concentrations of 25(OH)D were significantly higher.

CONCLUSIONS

The CYP2R1-TT and CYP24A1-AG variants have measurable effects on the vitamin D pathway. It seems unlikely that they will be clinically relevant in isolation, but they may be members of the large pool of infrequent mutations contributing to different risks for the vitamin D deficiency phenotype.

Sex differences in vitamin D and behavioral profiles among children with allergic diseases

Previous studies have suggested that vitamin D has a protective effect on allergic diseases, while an individual's sex may have a moderating effect on the relationship between vitamin D and allergic-related immunity. This study aimed to determine the role of vitamin D in children with coexisting allergic diseases in the context of sex differences and to explore the behavioral profiles of these patients. We recruited a total of 103 children with atopic diseases and divided them into four groups: males with one allergic disease (MA1, n = 20), males with two or more allergic diseases (MA2, n = 26), females with one allergic disease (FA1, n = 30), and females with two or more allergic diseases (FA2, n = 27). We measured serum calcium levels using the colorimetric method and serum 25-OH vitamin D total levels using electrochemiluminescence immunoassay. We found that MA2 had significantly lower vitamin D levels than MA1 and FA2. The levels of IgE were negatively correlated with vitamin D in females, whereas the levels of IgE were not significantly correlated with vitamin D in males. Furthermore, serum IgE was significantly correlated with children's adaptive skills, and different sexes were associated with different aspects of adaptive skills. Our findings suggest a protective role of vitamin D in the development of one allergic disease against the coexistence of allergic diseases in males, as well as extend the evidence for sex differences in immunity by demonstrating a sex-different correlation between IgE and vitamin D and the relationship between IgE and children's adaptive skills.

Vitamin D: An Overview of Gene Regulation, Ranging from Metabolism to Genomic Effects

Vitamin D is a pro-hormone characterized by an intricate metabolism and regulation. It is well known for its role in calcium and phosphate metabolism, and in bone health. However, several studies have assessed a huge number of extra-skeletal functions, ranging from cell proliferation in some oncogenic pathways to antioxidant and immunomodulatory functions. Vitamin D exerts its role by binding to VDRs (vitamin D receptors), which are located in many different tissues. Moreover, VDRs are able to bind hundreds of genomic loci, modulating the expression of various primary target genes. Interestingly, plenty of gene polymorphisms regarding VDRs are described, each one carrying a potential influence against gene expression, with relapses in several chronic diseases and metabolic complications. In this review, we provide an overview of the genetic aspects of vitamin D and VDR, emphasizing the gene regulation of vitamin D, and the genetic modulation of VDR target genes. In addition, we briefly summarize the rare genetic disease linked to vitamin D metabolism.

Mast Cells and Vitamin D Status: A Clinical and Biological Link in the Onset of Allergy and Bone Diseases

The immune system is made up by an extremely composite group of cells, whose regulated and harmonious activity is fundamental to maintain health. The mast cells are an essential effector of inflammatory response which is characterized by a massive release of mediators accumulated in cytoplasmic secretory granules. However, beyond the effects on immune response, mast cells can modify bone metabolism and are capable of intervening in the genesis of pathologies such as osteoporosis and osteopenia. Vitamin D is recognized to induce changes in bone metabolism, but it is also able to influence immune response, suppressing mast cell activation and IgE synthesis from B cells and increasing the number of dendritic cells and IL-10-generating regulatory T cells. Vitamin D deficit has been reported to worsen sensitization and allergic manifestations in several different experimental models. However, in clinical situations, contradictory findings have been described concerning the correlation between allergy and vitamin D deficit. The aim of this review was to analyze the close relationships between mast cells and vitamin D, which contribute, through the activation of different molecular or cellular activation pathways, to the determination of bone pathologies and the onset of allergic diseases.

Pre- and Postnatal Vitamin D Status and Allergy Outcomes in Early Childhood

The dramatic increase in the prevalence of allergic disease in recent decades reflects environmental and behavioural changes that have altered patterns of early immune development. The very early onset of allergic diseases points to the specific vulnerability of the developing immune system to environmental changes and the development of primary intervention strategies is crucial to address this unparalleled burden. Vitamin D is known to have immunomodulatory functions. While allergic disease is multifactorial, associations with reduced sunlight exposure have led to the hypothesis that suboptimal vitamin D levels during critical early periods may be one possible explanation. Interventions to improve vitamin D status, especially in early life, may be the key to allergic disease prevention.

The Foetal Origins of Allergy and Potential Nutritional Interventions to Prevent Disease

The first nine months from conception to birth involves greater changes than at any other time in life, affecting organogenesis, endocrine, metabolic and immune programming. It has led to the concept that the “first 1000 days” from conception to the second birthday are critical in establishing long term health or susceptibility to disease. Immune ontogeny is predominantly complete within that time and is influenced by the maternal genome, health, diet and environment pre-conception and during pregnancy and lactation. Components of the immunological protection of the pregnancy is the generation of Th-2 and T-regulatory cytokines with the consequence that neonatal adaptive responses are also biased towards Th-2 (allergy promoting) and T-regulatory (tolerance promoting) responses. Normally after birth Th-1 activity increases while Th-2 down-regulates and the evolving normal human microbiome likely plays a key role. This in turn will have been affected by maternal health, diet, exposure to antibiotics, mode of delivery, and breast or cow milk formula feeding. Complex gene/environment interactions affect outcomes. Many individual nutrients affect immune mechanisms and variations in levels have been associated with susceptibility to allergic disease. However, intervention trials employing single nutrient supplementation to prevent allergic disease have not achieved the expected outcomes suggested by observational studies. Investigation of overall dietary practices including fresh fruit and vegetables, fish, olive oil, lower meat intake and home cooked foods as seen in the Mediterranean and other healthy diets have been associated with reduced prevalence of allergic disease. This suggests that the “soup” of overall nutrition is more important than individual nutrients and requires further investigation both during pregnancy and after the infant has been weaned. Amongst all the potential factors affecting allergy outcomes, modification of maternal and infant nutrition and the microbiome are easier to employ than changing other aspects of the environment but require large controlled trials before recommending changes to current practice.

An Overview of Environmental Risk Factors for Food Allergy

IgE-mediated food allergy is an increasing public health concern in many regions around the world. Although genetics play a role in the development of food allergy, the reported increase has occurred largely within a single generation and therefore it is unlikely that this can be accounted for by changes in the human genome. Environmental factors must play a key role. While there is strong evidence to support the early introduction of allergenic solids to prevent food allergy, this is unlikely to be sufficient to prevent all food allergy. The purpose of this review is to summarize the evidence on risk factors for food allergy with a focus the outdoor physical environment. We discuss emerging evidence of mechanisms that could explain a role for vitamin D, air pollution, environmental greenness, and pollen exposure in the development of food allergy. We also describe the recent extension of the dual allergen exposure hypothesis to potentially include the respiratory epithelial barrier in addition to the skin. Few existing studies have examined the relationship between these environmental factors with objective measures of IgE-mediated food allergy and further research in this area is needed. Future research also needs to consider the complex interplay between multiple environmental factors.

Epigenetics in Food Allergy and Immunomodulation

Food allergy (FA) is an increasing problem worldwide and, over recent years, its prevalence is rising in developed countries. Nowadays, the immunological and cellular processes that occur in the allergic reactions are not fully understood, which hampers the development of in vitro diagnostic tools and further treatment options. Moreover, allergic diseases could be reinforced by environmental exposure and genetic modifications. Gene expression can be controlled by different epigenetic mechanisms like DNA methylation, histone modifications, and microRNAs. In addition, several environmental factors such as dietary components (vitamin D, butyrate, folic acid) are able to regulate this epigenetic mechanism. All these factors produce modifications in immune genes that could alter the development and function of immune cells, and therefore the etiology of the disease. Furthermore, these epigenetic mechanisms have also an influence on immunomodulation, which could explain sustained responsiveness or unresponsiveness during immunotherapy due to epigenetic modifications in key genes that induce tolerance in several FA. Thus, in this review we focus on the different epigenetic mechanisms that occur in FA and on the influence of several dietary components in these gene modifications.

The Effect of Serum Vitamin D Level on Allergic Rhinitis Symptoms in Children

Background: Allergic rhinitis (AR) is a chronic disease that is becoming increasingly common worldwide and has a negative impact on school performance, work performance, and quality of life. The aim of this study was to investigate the effect of vitamin D on the symptoms of AR in children. Methods: Serum vitamin D levels of children with AR and age-matched healthy controls were compared using the high-pressure liquid chromatography method. The relationship between serum vitamin D levels and symptoms and severity of AR was then examined. Results: The study included 137 patients diagnosed with AR (76 males, 61 females; median age: 11 years). Serum vitamin D levels were lower in the patient group than in the control group (P = 0.001), lower in all aeroallergen groups (mites, pollen, and multiple inhalants) than in the healthy control group (P = 0.001), and lower in both the perennial AR group and the seasonal AR group than in the control group (P = 0.001). Spearman correlation analysis showed that there was no correlation between symptom score and vitamin D level (r_s = -0.099; P = 0.25). Conclusions: We found no correlation between serum vitamin D level and symptoms and severity of AR. Serum vitamin D levels were lower in children with AR than in healthy children.

A narrative review of vitamin D and food allergy in infants and children

OBJECTIVE

This article summarizes the research progress on the association of vitamin D and food allergy in infants and children.

BACKGROUND

In recent years, food allergy seriously has affected the quality of life of children and adults. Vitamin D is known to be involved in calcium and phosphorus metabolism, and recent research has demonstrated that vitamin D can also affect the immune regulation of food allergy.

METHODS

The present study summarizes the research progress on the association of vitamin D and food allergy in infants and children. We searched the PubMed database to identify studies on the association of vitamin D and food allergy published between January 2003 and August 2021.

CONCLUSIONS

Vitamin D in the body through a number of steps into the final formation of biological effects. The implications of postnatal vitamin D levels for food allergy may be even greater. Vitamin D can prevent the intestinal immune system from being exposed to allergens by maintaining the integrity of the mucosal barrier. Many clinical studies believe that vitamin D supplementation can improve infants' and children's food allergy, however, some show negative results or opposite results. A lot of laboratory studies have confirmed that vitamin D is involved in the immune regulation of food allergy. Evidence indicates there may be a nonlinear relationship between vitamin D and food allergy. Further researches need to be launched.

Vitamin D: can the sun stop the atopic epidemic?

PURPOSE OF REVIEW

To review recent evidence on the capacity of vitamin D to prevent atopic disease, focussing on food allergy and asthma, and potential underlying mechanisms.

RECENT FINDINGS

The incidence of allergic disease continues to increase worldwide. Vitamin D status is influenced by sun exposure and dietary intake. Vitamin D deficiency is linked to an increased incidence of allergic disease and asthma. These associations are generally strongest in early life. The capacity of vitamin D to enhance antimicrobial pathways, promote peripheral immunological tolerance and maintain mucosal barrier integrity may underlie these associations. Interventional studies have addressed the capacity of vitamin D supplementation in utero and early life to reduce the incidence of disease. Ancillary studies have provided insights into potential biological mechanisms linked to these effects.

SUMMARY

Observational studies show an inverse association between vitamin D levels and development of food allergy and asthma. Secondary analyses of two recent interventional studies suggest that achieving vitamin D sufficiency throughout pregnancy reduces the incidence of asthma/recurrent wheeze at 3 years. Longitudinal studies of vitamin D requirements in utero and postnatally, better understanding of factors that influence bioavailability of vitamin D and mechanistic insights into vitamin D effects on neonatal-specific immune pathways are awaited.

Association of Vitamin D Metabolism Gene Polymorphisms with Autoimmunity: Evidence in Population Genetic Studies

A high prevalence of vitamin D (calcidiol) serum deficiency has been described in several autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (AR), and systemic lupus erythematosus (SLE). Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. The 90% of genetic variability takes place in the form of single nucleotide polymorphisms (SNPs), and SNPs in genes related to vitamin D metabolism have been linked to influence the calcidiol serum levels, such as in the vitamin D binding protein (VDBP; rs2282679 GC), 25-hydroxylase (rs10751657 CYP2R1), 1α-hydroxylase (rs10877012, CYP27B1) and the vitamin D receptor (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) VDR). Therefore, the aim of this comprehensive literature review was to discuss the current findings of functional SNPs in GC, CYP2R1, CYP27B1, and VDR associated to genetic risk, and the most common clinical features of MS, RA, and SLE.

Serum vitamin D levels in patients with vernal keratoconjunctivitis and its relationship with disease severity

Purpose

To evaluate the serum vitamin D levels of patients with vernal keratoconjunctivitis (VKC)

Method

A total of 39 VKC patients (21 males and 18 females) and 32 healthy individuals (19 males and 13 females) were enrolled in this study with the mean age of 18.38 ± 8.83 and 21.6 ± 9.43, respectively. The type and the grade of VKC were identified for each patient and serum 25-hydroxyvitamin D (25(OH)D) levels of all subjects were evaluated.

Results

The patients affected by VKC had statistically significant lower 25(OH)D levels (27.64 ± 8.50 ng/mL) than healthy subjects group (35.96 ± 11.34 ng/mL) ( p = 0.001). A reverse correlation was found between the serum vitamin D levels and the severity of the VKC but it was not statistically significant ( r = −0.159, p = 0.33). Besides, there were a few cases with severe and very severe VKC (2 in grade 3 and 4 in grade 4). Patients with the mixed type of the disease had lower serum vitamin D levels in comparison to tarsal and limbal forms but the difference was not statistically significant ( p = 0.38).

Conclusion

This study shows that the patients affected by VKC have lower vitamin D levels in comparison to healthy subjects and the screening of all patients with VKC for vitamin D levels seems rational.

Respiratory function and respiratory complications in spinal cord injury: protocol for a prospective, multicentre cohort study in high-income countries

INTRODUCTION

Pneumonia is one of the leading complications and causes of death after a spinal cord injury (SCI). After a cervical or thoracic lesion, impairment of the respiratory muscles decreases respiratory function, which increases the risk of respiratory complications. Pneumonia substantially reduces patient's quality of life, may prolong inpatient rehabilitation time, increase healthcare costs or at worse, lead to early death. Respiratory function and coughing can be improved through various interventions after SCI, but the available evidence as to which aspect of respiratory care should be optimised is inconclusive. Furthermore, ability of respiratory function parameters to predict pneumonia risk is insufficiently established. This paper details the protocol for a large-scale, multicentre research project that aims to evaluate the ability of parameters of respiratory function to predict and understand variation in inpatient risk of pneumonia in SCI.

METHODS AND ANALYSIS

RESCOM, a prospective cohort study, began recruitment in October 2016 across 10 SCI rehabilitation centres from Australia, Austria, Germany, the Netherlands and Switzerland. Inpatients with acute SCI, with complete or incomplete cervical or thoracic lesions, 18 years or older and not/no more dependent on 24-hour mechanical ventilation within the first 3 months after injury are eligible for inclusion. The target sample size is 500 participants. The primary outcome is an occurrence of pneumonia; secondary outcomes include pneumonia-related mortality and quality of life. We will use the longitudinal data for prognostic models on inpatient pneumonia risk factors.

ETHICS AND DISSEMINATION

The study has been reviewed and approved by all local ethics committees of all participating centres. Study results will be disseminated to the scientific community through peer-reviewed journals and conference presentations, to the SCI community, other stakeholders and via social media, newsletters and engagement activities.

TRIAL REGISTRATION DETAILS

ClinicalTrials.gov NCT02891096.

Association of Vitamin D Pathway Gene CYP27B1 and CYP2R1 Polymorphisms with Autoimmune Endocrine Disorders: A Meta-Analysis

BACKGROUND

Studies on organ-specific autoimmune endocrine disorders showed correlations between disease risks and vitamin D pathways gene variants, such as CYP27B1 rs10877012 and rs4646536, or CYP2R1 rs10741657 single nucleotide polymorphisms. However, previous works presented inconsistent conclusions. Our study aimed at assessing the association of CYP27B1 and CYP2R1 polymorphisms with autoimmune endocrine disorder susceptibility using the meta-analysis method.

METHODS

Case-control studies of the subject of interest were identified from the databases Pubmed, Embase, Cochrane Library, and China National Knowledge Infrastructure. Studies that met inclusion and quality criteria were pooled. Observational outcomes were diagnosis of autoimmune Addison's disease, Graves disease, Hashimoto thyroiditis, or type 1 diabetes mellitus. Statistical analysis was performed using software STATA 16.0.

RESULTS

A total of 14 studies involving 12 929 patients (2243 autoimmune Addison disease, 1253 Graves disease, 612 Hashimoto thyroiditis, 8821 type 1 diabetes), and 12 907 healthy control subjects were pooled for meta-analysis. The rs10877012 minor allele A and its homozygote and heterozygote conferred low overall disease risk (OR [odds ratio] = 0.748, 95% CI [confidence interval] 0.620-0.902 in dominant model; OR = 0.709, 95% CI 0.571-0.879 in recessive model; OR = 0.777, 95% CI 0.674-0.895 in the allele model). The population carrying rs4646536 minor allele C and its homozygote and heterozygote showed decreased overall autoimmune endocrine disorders risk (OR = 0.849, 95% CI 0.748-0.963; OR = 0.868, 95% CI 0.790-0.955; OR = 0.915, 95% CI 0.875-0.957 in the dominant, recessive, and allele model, respectively). No significant genetic association was found for rs10741657.

CONCLUSION

Our study suggested CYP27B1 polymorphisms rs10877012 minor allele A and rs4646536 minor allele C were negatively related to susceptibilities of organ-specific autoimmune endocrine diseases.

Role of Vitamin D in Prevention of Food Allergy in Infants

The prevalence of food allergy is increasing over the last decades. The role of vitamin D in the prevention of food allergy has been largely investigated. Its role on the physiology of calcium and bone is known, but calcitriol (active form of the vitamin D) also influences the epithelial cells, T cells, B cells, macrophages, and dendritic cells. Almost all cells of the adaptive immune system express the vitamin D receptor, making them also capable of being vitamin responsive. Specifically considering the potential role of vitamins in food allergy, vitamin D has been shown to affect several mechanisms that promote immunologic tolerance, including the T regulatory cell function and the induction of tolerogenic dendritic cells. The target of our review is to evaluate the role of vitamin D in the prevention of food allergy in children. There are contradictory data on the relationship among the vitamin D deficiency and the developing of food allergy. Some studies associate lower exposure to sunlight to food allergy; on the other hand, further research has found that higher vitamin D levels could increase the likelihood of allergic sensitization and food allergy. Therefore, there is an urgent need for well-planned randomized controlled trials on vitamin D supplementation, with particular regard to the prevention of food allergy. The role of vitamin D beyond bone and calcium metabolism is not fully understood.

Association study between genetic variants in vitamin D metabolism related genes and childhood autism spectrum disorder

Vitamin D deficiency has been implicated as a risk factor for autism spectrum disorder (ASD). This case-controlled study was to determine the association between single nucleotide polymorphisms (SNPs) in genes encoding vitamin D metabolism related enzymes and childhood ASD in a Chinese Han population. Both autistic children and age-and gender-matched healthy controls were recruited from September 2012-November 2017. The severity of ASD was evaluated by the childhood autism rating scale (CARS). Taqman probe based real-time PCR was applied to examine genotypes. The association between SNPs and the risk of ASD or the disease severity was examined through the logistic regression. This study recruited 249 children with ASD and 353 healthy controls. The G/A genotype (P = 0.0112) or the G allele (P = 0.0117) of CYP24A1 rs17219315, and the G/A genotype of CYP27B1 rs4646536 (P = 0.0341) were significantly associated with an increased risk of ASD. In addition, multivariate analysis found that A allele of both CYP2R1 rs12794714 (P = 0.0159) and CYP27B1 rs4646536 (P = 0.0268) were significantly associated with the severity of ASD. Genetic polymorphisms in vitamin D metabolism related enzymes are associated with the risk of childhood ASD and the severity of the disease.

The association between vitamin D levels and burn factors in different burn types

Background

Patients with burns present with different clinical features depending on the types of burn injury and burn patients with lower levels of vitamin D have worse prognoses and more complications. The study aims to investigate the association between vitamin D levels and burn factors according to each burn type in relation to early intensive rehabilitation therapy initiated for inpatients with burns.

Methods

In this retrospective study, we enrolled 757 of 1716 inpatients who underwent rehabilitative therapy between May 2013 and April 2017. Burn types were divided into flame burn, electrical burn and other burns, including scalding, contact and chemical burns. Age, burned body surface area (BSA), wound healing time (WHT), length of hospital stay (LOS) and body mass index were analysed between vitamin D deficient and non-deficient patient groups using Student’s t-tests, or Mann-Whitney U test and among three burn types using one-way analysis of variance (ANOVA) or Kruskal-Wallis one-way ANOVA. The relationship between vitamin D levels and burn factors was evaluated using Pearson's or Spearman's correlation coefficient tests, and multiple linear regression analysis in different burn groups.

Results

In total, 88.9% patients were vitamin D deficient, and these patients had a larger burned BSA (p = 0.015) and longer WHT and LOS (all p < 0.001) than non-deficient patients. Burned BSA, WHT and vitamin D levels showed significant differences in their mean values according to three burn types (all p < 0.001). WHT was a communal factor significantly associated with vitamin D levels in all three burn types (p < 0.05). The WHT cut-off points to predict vitamin D deficiency were 55 days for flame burn (p < 0.001) and 62.5 days for electrical burn (p = 0.001).

Conclusions

WHT across all three burn types was a common factor associated with vitamin D levels for inpatients with burns who had undergone rehabilitative therapy. Electrical burn patients with vitamin D deficiency, even those with a low burned BSA percentage, showed prolonged wound healing over a two-month post-burn period. Independent of burned BSA, nutritional intervention concerning vitamin D in relation to burn wound healing should be considered to guide early initiation of intensive rehabilitation therapy.

Vitamin D in Type 2 Diabetes: Genetic Susceptibility and the Response to Supplementation

Variants of vitamin D metabolism-genes may predispose to type 2 diabetes (T2D). This study investigated the impact of these variants on disease susceptibility, Vitamin D, parathyroid hormone, C-peptide and HbA1c levels before and after cholecalciferol supplementation in patients with T2D.Twelve polymorphisms within CYP2R1, CYP27B1, DBP, VDR and CYP24A1 were genotyped in 553 T2D patients and 916 controls. In addition 65 patients receiving either cholecalciferol or placebo were analyzed during 6 months intervention and 6 months follow-up.T2D risk alleles are VDR rs7975232 "G" (p_c=0.031), rs1544410 "G" (p_c=0.027) and CYP2R1 rs10741657 "A" (p_c=0.016). Patients with genotypes CYP27B1 rs10877012 "CC" (p_c=4x10^-5), DBP rs7041 "GG" (p_c=0.003), rs4588 "CC" (p_c = 3x10^-4), CYP24A1 rs2585426 "CG" (p_c=0.006) and rs2248137 "CG" (p_c=0.001) showed lower 25(OH)D3 and DBP rs4588 "CC" lower 1,25(OH)2D3 levels (p_c=0.005). Whereas DBP rs4588 "CC" (p_c=0.009), CYP27B1 rs10877012 "AC" (p_c=0.059), VDR rs7975323 "AG" (p_c=0.033) and rs1544410 "GG" (p_c=0.013) are associated with higher 25(OH)D3 levels at 6 months' follow-up. Significant PTH suppression was detected for CYP2R1 "AG" (p_c=0.002), DBP rs4588 "CC" (p_c<0.001), VDR rs110735810 "CT" (p_c<0.001) and CYP24A1 rs2248137 "GG" (p_c=0.021).Genetic variants of the vitamin D system predispose to type 2 diabetes and regulate - partially - vitamin D metabolism, concentrations and the vitamin D status. Vitamin D insufficiency is a T2D risk factor. The response to cholecalciferol supplementation can be measured as 25(OH)D3 increment and PTH suppression. This process is regulated by genes of the vitamin D system conferring modest T2D risk.

The Role of Vitamin D in Respiratory Allergies Prevention. Why the Effect Is so Difficult to Disentangle?

Asthma and allergic rhinitis are the most common chronic childhood diseases with an increasing prevalence worldwide. There is an urgent need to look for methods of preventing allergic diseases from an early age. The relationship between vitamin D status and allergic diseases has been discussed in several studies recently. 25-hydroxyvitamin D (25(OH)D) is suggested to affect the development and/or severity of asthma and allergic rhinitis. Observational studies have seemed to confirm that vitamin D deficiency may contribute to an increase in allergy and asthma. Following interventional studies, however, have yielded ambiguous results. In this review, we describe recent findings regarding 25(OH)D impact on allergic diseases and provide a systematic analysis of the causes of great variability of the achieved results in different studies.

Vitamin D and Immunity in Infants and Children

The last couple of decades have seen an explosion in our interest and understanding of the role of vitamin D in the regulation of immunity. At the molecular level, the hormonal form of vitamin D signals through the nuclear vitamin D receptor (VDR), a ligand-regulated transcription factor. The VDR and vitamin D metabolic enzymes are expressed throughout the innate and adaptive arms of the immune system. The advent of genome-wide approaches to gene expression profiling have led to the identification of numerous VDR-regulated genes implicated in the regulation of innate and adaptive immunity. The molecular data infer that vitamin D signaling should boost innate immunity against pathogens of bacterial or viral origin. Vitamin D signaling also suppresses inflammatory immune responses that underlie autoimmunity and regulate allergic responses. These findings have been bolstered by clinical studies linking vitamin D deficiency to increased rates of infections, autoimmunity, and allergies. Our goals here are to provide an overview of the molecular basis for immune system regulation and to survey the clinical data from pediatric populations, using randomized placebo-controlled trials and meta-analyses where possible, linking vitamin D deficiency to increased rates of infections, autoimmune conditions, and allergies, and addressing the impact of supplementation on these conditions.

CYP27B1 Gene Polymorphism rs10877012 in Patients Diagnosed with Colorectal Cancer

Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide. Intestinal cells are CYP27B1 gene expression sites and, as a consequence, they are capable of converting pro-vitamin D into the active paracrine and autocrine forms. It was demonstrated that rs10877012 polymorphism in the CYP27B1 gene influenced the circulating vitamin D level. This provided a rationale for determining the role that this polymorphism plays in the risk of developing colon cancer. In this study, we investigated the association of rs10877012 (T/G) polymorphism in the CYP27B1 gene with CRC susceptibility. The study population (n = 325) included CRC patients (n = 106) and healthy controls (n = 219). DNA was extracted from peripheral leukocytes and analyzed for the CYP27B1 polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We found an association between the presence of the T allele at the polymorphic site (odds ratio (OR) = 2.94; 95% CI 1.77–4.86; p < 0.0001) and a decreased CRC incidence.

Relationship between serum 25-hydroxyvitamin D and inflammatory cytokines in Nigerian children with asthma

Background: Childhood asthma involves a network of mutually interacting inflammatory mediators and cytokines. The influence of serum vitamin D (an immunomodulatory agent) on these cytokines is poorly understood. This study sets out to determine the relationship between serum T-helper cells type 1 cytokines (Interleukins ILs-1β, 2, 6, 8 and 10), type 2 cytokines (ILs 3, 4,5,9,13), ILs-12, 17 and 25-hydroxyvitamin D (25-OHD) in Nigerian children with asthma.Methods: Children with physician-diagnosed asthma and non-asthmatics aged 2-15 years were consecutively recruited at a tertiary center in Nigeria. Serum 25-OHD and cytokines were assayed using chromatography method and association between these parameters determined.Results: A total of 180 children (90 for each group; mean age 7.5 ± 3.9 years; M:F 1.9:1) were recruited. Fifty-six (76.7%) asthmatics had mild intermittent form and symptoms were sub-optimally controlled in 16 (21.9%). The mean (SD) serum Vitamin D was lower in children with asthma (38.8 ± 17.0 ng/ml vs. 45.5 ± 16.6 ng/ml vs. p = 0.023). Also more proportion of children with asthma had suboptimal serum vitamin D level (26.0% vs. 8.8%; p = 0.022). Deficient vitamin D state was associated with higher serum Th₁ and Th₂ cytokines compared to insufficient state, but the highest cytokine levels were observed in normal vitamin D state. There was significant positive correlation between serum vitamin D and Th₁ cytokines IL-2 and IL-8 as well as Th₂ cytokines (ILs-3, 4, 5 and 9), but negative correlation with IL-13Conclusions: Serum Vitamin D and cytokines were lower in a sample of Nigerian children with asthma than controls. Vitamin D status was not related to asthma severity and control. Serum 25-OHD seems to have a non-linear relationship with Th₁ and Th₂ cytokines in Nigerian asthmatics.

The association of vitamin D status and supplementation during pregnancy with gestational diabetes mellitus: a Chinese prospective birth cohort study

BACKGROUND

Previous studies have shown conflicting findings regarding the relation of vitamin D status and supplementation during pregnancy with gestational diabetes mellitus (GDM). Most of these studies hypothesized that 25-hydroxyvitamin D [25(OH)D] concentrations were associated with GDM risk and glucose metabolism based on linear association models.

OBJECTIVES

We aimed to estimate the associations of 25(OH)D concentrations and vitamin D supplementation with GDM risk and glucose metabolism and determine the threshold concentrations of 25(OH)D that could significantly affect glucose metabolism and GDM risk.

METHODS

In a prospective birth cohort study, we collected information about sociodemographic characteristics, health status, and lifestyle from 4984 pregnant women. Vitamin D supplementation and 25(OH)D concentrations were assessed in the second trimester. Data from the 75-g oral-glucose-tolerance test were obtained at 24-28 weeks of gestation.

RESULTS

A total of 922 (18.5%) women were diagnosed with GDM. Compared with women with 25(OH)D concentrations <25 nmol/L, the GDM risk was significantly lower in women with 25(OH)D concentrations ranging from 50 to 75 nmol/L (RR: 0.74; 95% CI: 0.58, 0.95) and >75 nmol/L (RR: 0.40; 95% CI: 0.22, 0.70). The curve-fitting models suggested a significant large reduction in GDM risk, fasting plasma glucose, and area under the curve of glucose with increasing 25(OH)D concentrations only for concentrations >50 nmol/L. Consistently, GDM risk was significantly reduced only in women who took 400-600 IU vitamin D/d (RR: 0.83; 95% CI: 0.70, 0.97) with a mean 25(OH)D concentration of 50 nmol/L but not in women taking vitamin D sometimes with a mean 25(OH)D concentration of 40 nmol/L.

CONCLUSIONS

GDM risk was significantly reduced only in pregnant women with 25(OH)D concentrations >50 nmol/L. Pregnant women taking 400-600 IU vitamin D/d with mean 25(OH)D concentrations of 50 nmol/L had a lower risk of GDM.

The Role of Vitamin D Deficiency in Children With Recurrent Wheezing-Clinical Significance

Recurrent wheezing (RW) in infancy is one of the most frequent reasons for parents to consult health care providers and creates a significant global burden. Clinical course of RW is difficult to predict, also which infants will progress to asthma, since no valid biomarkers have been established. Identification of those infants with RW who are at risk of further recurrences and/or severe acute respiratory tract infection (ARTI) could help pediatricians to improve their therapeutic decisions. Increasing research interest is focused on the extra-skeletal actions of vitamin D (VD) and the clinical impact of VD insufficiency/deficiency. As VD deficiency could be a risk factor for causing RW in children, measurement of their serum level of 25-hydroxycholecalciferol [25(OH)D] is recommended. In the case of deficiency, VD administration is recommended in age-appropriate doses for at least 6 weeks, until achievement of normal blood 25(OH)D level, followed by supplementation as long as exposure to sun is inadequate. Higher doses of VD given in an attempt to prevent asthma development appear to be of no additional benefit. In children with severe ARTI, VD level is recommended to be assess.

Food Allergies and Ageing

All over the world, there is an increase in the overall survival of the population and the number of elderly people. The incidence of allergic reactions is also rising worldwide. Until recently, allergies, and in particular food allergies (FAs), was regarded as a pediatric problem, since some of them start in early childhood and may spontaneously disappear in adulthood. It is being discovered that, on the contrary, these problems are increasingly affecting even the elderly. Along with other diseases that are considered characteristics of advanced age, such as cardiovascular, dysmetabolic, autoimmune, neurodegenerative, and oncological diseases, even FAs are increasingly frequent in the elderly. An FA is a pleiomorphic and multifactorial disease, characterized by an abnormal immune response and an impaired gut barrier function. The elderly exhibit distinct FA phenotypes, and diagnosis is difficult due to frequent co-morbidities and uncertainty in the interpretation of in vitro and in vivo tests. Several factors render the elderly susceptible to FAs, including the physiological changes of aging, a decline in gut barrier function, the skewing of adaptive immunity to a Th2 response, dysregulation of innate immune cells, and age-related changes of gut microbiota. Aging is accompanied by a progressive remodeling of immune system functions, leading to an increased pro-inflammatory status where type 1 cytokines are quantitatively dominant. However, serum Immunoglobulin E (IgE) levels and T helper type 2 (Th2 cytokine production have also been found to be increased in the elderly, suggesting that the type 2 cytokine pattern is not necessarily defective in older age. Dysfunctional dendritic cells in the gut, defects in secretory IgA, and decreased T regulatory function in the elderly also play important roles in FA development. We address herein the main immunologic aspects of aging according to the presence of FAs.

Infant Feeding, Vitamin D and IgE Sensitization to Food Allergens at 6 Years in a Longitudinal Icelandic Cohort

Nordic Nutrition Recommendations (NNR) recommend exclusive breastfeeding until 6 months, partial breastfeeding until 1 year or longer and irrespective of breastfeeding, avoiding solid foods before 4 months. Strong evidence was found for benefits of breastfeeding regarding growth and infections but limited/inconclusive evidence regarding atopic disease and asthma. Vitamin D is of special interest in the Nordic diet. The aim of this prospective study was to compare infant feeding and vitamin D between immunoglobulin E (IgE) sensitized (n = 14) and non-sensitized (n = 130) children at 6 years. Information on diet and vitamin D supplement use were collected with dietary recall (<5 months), 1-d food records (5 and 6 months) and 3-d weighed food records (12 months and 6 years). Serum-specific IgE-antibodies against milk, egg, cod, wheat, soy and peanut (cut-off specific IgE ≥ 0.35 kUA/L) were measured at 6 years and serum 25-hydroxyvitamin D at 12 months and 6 years. At 4 months, 57% of IgE sensitized vs. 23% of non-sensitized children (p < 0.01) had received solid food. At 12 months, IgE sensitized children had a lower intake of vitamin D (median (25th, 75th percentiles): 3.9 μg/d (3.2, 7.2) vs. 8.1 μg/d (4.4, 12.3), p = 0.03) and at 6 years, fewer used vitamin D supplements regularly (23% vs. 56%, p = 0.03). Introduction of solid foods prior to 4 months increased the odds of IgE-sensitization, OR = 4.9 (95%, CI = 1.4–16.6) and vitamin D supplement at 6 years decreased the odds of IgE-sensitization, OR = 0.2 (95%, CI = 0.1–0.98), adjusting for maternal smoking. These observations support the NNR in their recommendation against introducing complementary solid foods before the age of 4 months. Furthermore, they support encouraging vitamin D intake for young children at northern latitudes.

High-Dose Vitamin D Supplementation Does Not Prevent Allergic Sensitization of Infants

OBJECTIVE

To investigate the effect of vitamin D supplementation dose on allergic sensitization and allergic diseases in infants, and to evaluate whether vitamin D status in pregnancy and at birth are associated with infant allergy outcomes.

STUDY DESIGN

Altogether, 975 infants participated in a randomized, controlled trial of daily vitamin D supplementation of 10 μg (400 IU) or 30 μg (1200 IU) from the age of 2 weeks. At 12 months of age, food and aeroallergen IgE antibodies were measured, and the occurrence of allergic diseases and wheezing were evaluated.

RESULTS

We found no differences between the vitamin D supplementation groups in food (OR, 0.98; 95% CI, 0.66-1.46) or aeroallergen sensitization at 12 months (OR, 0.76; 95% CI,0.34-1.71). Allergic diseases or wheezing did not differ between groups, except for milk allergy which occurred more often in infants administered 30 μg vitamin D compared with the 10 μg dose (OR, 2.23; 95% CI, 1.00-4.96). Infants with high cord blood 25-hydroxyvitamin D (≥100 nmol/L) had a higher risk of food allergen sensitization compared with those with lower 25(OH)D concentration (75-99.9 nmol/L; OR, 2.00; 95% CI, 1.19-3.39).

CONCLUSIONS

High-dose vitamin D supplementation did not prevent allergic sensitization, allergic diseases, or wheezing during the first year of life. In contrast, we observed an increased risk of milk allergy in infants randomized to higher vitamin D supplementation, and an increased risk of allergic sensitization in infants with high cord blood vitamin D status, indicating a possible adverse effect of high concentrations of vitamin D.

The DALI vitamin D randomized controlled trial for gestational diabetes mellitus prevention: No major benefit shown besides vitamin D sufficiency

BACKGROUND & AIMS

As vitamin D deficiency is associated with an increased risk of gestational diabetes mellitus (GDM), we aimed to test vitamin D supplementation as a strategy to reduce GDM risk (evaluated after fasting plasma glucose (FPG), insulin resistance and weight gain) in pregnant overweight/obese women.

METHODS

The DALI vitamin D multicenter study enrolled women with prepregnancy body mass index (BMI) ≥ 29 kg/m², ≤19 + 6 weeks of gestation and without GDM. Participants were randomized to receive 1600 IU/day vitamin D3 or placebo (each with or without lifestyle intervention) on top of (multi)vitamins supplements. Women were assessed for vitamin D status (sufficiency defined as serum 25-hydroxyvitamin D (25(OH)D) ≥ 50 nmol/l), FPG, insulin resistance and weight at baseline, 24-28 and 35-37 weeks. Linear or logistic regression analyses were performed to assess intervention effects.

RESULTS

Average baseline serum 25(OH)D was ≥50 nmol/l across all study sites. In the vitamin D intervention arm (n = 79), 97% of participants achieved target serum vitamin 25(OH)D (≥50 nmol/l) at 24-28 weeks and 98% at 35-37 weeks vs 74% and 78% respectively in the placebo arm (n = 75, p < 0.001). A small but significantly lower FPG (-0.14 mmol/l; CI95 -0.28, -0.00) was observed at 35-37 weeks with the vitamin D intervention without any additional difference in metabolic status, perinatal outcomes or adverse event rates.

CONCLUSION

In the DALI vitamin D trial, supplementation with 1600 IU vitamin D3/day achieved vitamin D sufficiency in virtually all pregnant women and a small effect in FPG at 35-37 weeks. The potential of vitamin D supplementation for GDM prevention in vitamin D sufficient populations appears to be limited.

TRIAL REGISTRATION NUMBER

ISRCTN70595832.

Food allergy is linked to season of birth, sun exposure, and vitamin D deficiency

The season of birth and ultraviolet B exposure have been related to the occurrence of food allergy. The levels of vitamin D produced from skin by ultraviolet B exposure might reflect this relationship. Vitamin D is known to induce antimicrobial peptides, protect intestinal flora, enhance the gut epithelial barrier, suppress mast cell activation and IgE synthesis from B cells, and increase the number of tolerogenic dendritic cells and IL-10-producing regulatory T cells. Vitamin D deficiency has been shown to exacerbate sensitization and allergic symptoms in a murine model of food allergy. However, in clinical situations, contradictory observations have been reported regarding the relationship between food allergy and vitamin D deficiency/supplementation. In this review, we have explored the links between food allergy and vitamin D levels. One explanation for the discrepant findings is confounding factors such as race, age, residency, skin color, and epigenetic changes that contribute to vitamin D levels. In addition, the season of birth influences the development of atopic dermatitis, which could lead to food sensitization. Finally, ultraviolet radiation could lead to regulatory T cell expansion and immunosuppression, irrespective of vitamin D status. Based on our current understanding, we believe that correction of vitamin D deficiency by supplementation, appropriate skin care, and sufficient ultraviolet radiation exposure could alter the prognosis of food allergy. To identify potential treatment strategies for food allergy, it is essential to gain a better understanding of the appropriate levels of vitamin D and ultraviolet radiation exposure.

Mechanisms of gastrointestinal allergic disorders

Gastrointestinal (GI) allergic disease is an umbrella term used to describe a variety of adverse, food antigen-driven, immune-mediated diseases. Although these diseases vary mechanistically, common elements include a breakdown of immunologic tolerance, a biased type 2 immune response, and an impaired mucosal barrier. These pathways are influenced by diverse factors such as diet, infections, exposure to antibiotics and chemicals, GI microbiome composition, and genetic and epigenetic elements. Early childhood has emerged as a critical period when these factors have a dramatic impact on shaping the immune system and therefore triggering or protecting against the onset of GI allergic diseases. In this Review, we will discuss the latest findings on the molecular and cellular mechanisms that govern GI allergic diseases and how these findings have set the stage for emerging preventative and treatment strategies.

Respiratory muscle training in individuals with spinal cord injury: effect of training intensity and -volume on improvements in respiratory muscle strength

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To investigate the effect of training intensity and -volume on improvements in respiratory muscle strength in individuals with spinal cord injury (SCI).

SETTING

SCI rehabilitation center in Switzerland.

METHODS

Inpatients with SCI, lesion level C4-T12, who had at least 10 individualized inspiratory muscle training sessions with respiratory function measurements before and after the training period. Multiple regression analysis with natural logarithmic (ln) transformation of the outcome values was used to examine the effect of training intensity and -volume, lesion level and completeness, and baseline respiratory muscle strength on improvements in respiratory muscle strength.

RESULTS

Overall, 67 individuals were analyzed. Variation in PI_max was explained by PI_max at baseline and training intensity. This adjusted effect size suggested a 7% (95% CI 2.8 to 11.6%) increase in PI_max per 10 units of increase in training intensity. Controlling for the variation in baseline PE_max, the effect of training intensity on PE_max was conditional on AIS (p < 0.021). While individuals with motor complete lesions showed a 6.8% (95% CI 2.1 to 11.7%) increase in PE_max per 10 units of increase in training intensity, the corresponding adjusted effect size in those with motor incomplete lesions was 0.1% (95% CI -4.3 to 4.5%). The full models explained 57 and 60% of the variance of lnPI_max and lnPE_max, respectively.

CONCLUSION

The intensity of inspiratory muscle training was more relevant than training volume for the improvement of respiratory muscle strength in individuals with SCI. Thus, training intensity should be chosen as high as possible.

Complex relationships between vitamin D and allergic sensitization among Puerto Rican 2-year-old children

BACKGROUND

In the United States, Puerto Ricans have a higher prevalence of asthma than other Latino ethnicities. Low vitamin D levels for children living in northern climates could be a factor.

OBJECTIVE

To assess serum 25-hydroxyvitamin D [25(OH)D] distributions (a marker of vitamin D) and associations among vitamin D, allergic sensitization, early wheeze, and home/demographic factors.

METHODS

Puerto Rican infants born in New York City, with a maternal history of atopy, were enrolled in a birth cohort. Blood was collected at age 2 years (n = 154; 82 males and 72 females). Serum 25(OH)D and immunoglobulin E (IgE) (indoor allergen-specific and total) were determined using immunoassays. Home/demographic characteristics and respiratory symptoms were assessed by questionnaire.

RESULTS

The median concentration of 25(OH)D was 22.6 ng/mL; 32% were at risk of deficiency or inadequacy (<12 or 12-19 ng/mL). Serum 25(OH)D levels were lower in the heating (a surrogate for less sun exposure in colder months) compared with nonheating (26.1 vs 22.7 ng/mL, P = .02) season, but were not associated with allergen-specific IgE levels or with level of acculturation (measured by maternal birthplace). However, low 25(OH)D levels (below median) were associated with high total IgE >100 IU/mL (P = .01). Also, 25(OH)D concentrations differed between children who attended daycare and those who did not (21.8 vs 24.5 ng/mL; t test, P = .02). Serum 25(OH)D was not associated with wheeze or asthma by 2 years of age (P = .43).

CONCLUSION

Vitamin D deficiency, possibly linked with allergic pathways, may partially explain the trajectory for disproportionate asthma burden among Puerto Ricans, especially those born and raised in colder climates.

The Association between Polymorphisms of Vitamin D Metabolic-Related Genes and Vitamin D3 Supplementation in Type 2 Diabetic Patients

OBJECTIVE

To investigate the effect of single nucleotide polymorphisms (SNPs) of the key genes in vitamin D metabolic pathway on the serum 25(OH)D level after long-term vitamin D₃ supplementation and provide a theoretical basis for rational vitamin D₃ supplementation in diabetic patients with different genetic backgrounds.

METHODS

Patients with type 2 diabetes (T2DM) who met the inclusive criteria were given 800 IU of vitamin D₃ daily for 30 consecutive months. Serum 25(OH)D levels was measured at enrollment and every 6 months after enrollment. The average value of four-time measurements represented individual serum 25(OH)D level during vitamin D₃ supplementation. Multiplex TaqMan genotyping was used to determine the distribution of eight candidate SNPs in genes of DHCR7, CYP2R1, CYP27B1, CYP24A1, and VDR, which are key genes in the vitamin D metabolic pathway, in diabetic patients.

RESULTS

At baseline, the average serum 25(OH)D level was 22.71 ± 6.87 ng/mL, and 17.9% of patients had a ≥30 ng/mL level. During supplementation, the level of 25(OH)D increased significantly at each time point, and the average 25(OH)D level increased to 30.61 ± 5.04 ng/mL; however, there were 44.6% of patients whose serum 25(OH)D levels were still below 30 ng/mL. In the patients with CYP27B1 (rs10877012) G/T genotype, 71.79% achieved sufficient level of 25(OH)D, which was significantly higher than the other two genotypes (P < 0.05). Compared with those with T/T genotype, the RR of the patients with rs10877012 for <30 ng/mL level was 0.544 (95% CI: 0.291-0.917), and the RR after adjusting age and outdoor activity was 0.560 (95% CI: 0.292-0.970).

CONCLUSION

The serum 25(OH)D level in patients with diabetes mellitus after long-term vitamin D₃ supplementation is associated with CYP27B1 polymorphism. Patients with rs10877012 G/T allele have a better response to vitamin D₃ supplementation.

TRIAL REGISTRATION

This trial is registered with ChiCTR-IPC-17012657.

Mouse Chow Composition Influences Immune Responses and Food Allergy Development in a Mouse Model

Our diet is known to substantially influence the immune response not only by support of mucosal barriers but also via direct impact on immune cells. Thus, it was of great interest to compare the immunological effect of two mouse chows with substantial differences regarding micro-, macronutrient, lipid and vitamin content on the food allergic response in our previously established mouse model. As the two mouse chows of interest, we used a soy containing feed with lower fatty acid (FA) amount (soy-containing feed) and compared it to a soy free mouse chow (soy-free feed) in an established protocol of oral immunizations with Ovalbumin (OVA) under gastric acid suppression. In the animals receiving soy-containing feed, OVA-specific IgE, IgG1, IgG2a antibody levels were significantly elevated and food allergy was evidenced by a drop of body temperature after oral immunizations. In contrast, mice on soy-free diet had significantly higher levels of IL-10 and were protected from food allergy development. In conclusion, soy-containing feed was auxiliary during sensitizations, while soy-free feed supported oral tolerance development and food allergy prevention.

Vitamin D Level and Supplementation in Pediatric Atopic Dermatitis: A Randomized Controlled Trial

BACKGROUND:

Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by a pruritic eczematous rash. Evidence surrounding the role of serum vitamin D (VD) in modifying disease severity is inconsistent.

OBJECTIVES:

To determine whether VD levels are correlated with AD severity and the effects of VD supplementation on disease modification.

METHODS:

This was a 2-phase study, using a cross-sectional design to evaluate the relationship between VD level and severity, as well as a double-blinded, randomized control trial to elucidate the effects of VD supplementation. Patients aged 0 to 18 years with AD were included in phase 1, and disease severity and serum VD levels were determined. Those with renal, liver, or other dermatologic conditions were excluded. Patients with abnormal (<72.7 nmol/L) VD levels were eligible for phase 2 and to be randomized to either VD supplementation of 2000 IU/d or placebo. VD level and severity were assessed at baseline and 3 months.

RESULTS:

The 77 patients included in phase 1 had a mean (SD) age of 7.4 (4.5) years, and 45.5% (33/77) were female. Increased severity was significantly correlated with lower VD levels ( P = .015). Of the 45 patients included in phase 2, 21 and 24 were assigned to the supplementation and placebo arm, respectively. The mean (SD) change in severity did not differ significantly between the supplementation (15.35 [9.71]) and placebo (15.13 [8.97]) groups after 3 months of intervention ( P = .7).

CONCLUSION:

Although VD levels correlated with AD severity, VD supplementation did not significantly improve disease severity.

The Relationship between Serum Vitamin D Levels with Allergic Rhinitis Incidence and Total Nasal Symptom Score in Allergic Rhinitis Patients

BACKGROUND

Allergic diseases and vitamin D deficiency were found to have a relationship. However, there was limited number of studies on the relationship between vitamin D with allergic rhinitis (AR) and total nasal symptom scores (TNSS), particularly in determining the cut-off points of serum vitamin D levels which correlated to AR.

AIM

As this particular study has never been conducted in Indonesia, the main objective of this study was to investigate this issue.

METHODS

The research was conducted at Dr Soetomo Hospital, Surabaya in January 2017. A group of 30 subjects were recruited using consecutive sampling. Levels of serum vitamin D were measured using electrochemiluminescence immunoassay (ECLIA) method while the total nasal symptom scores were obtained by accumulating all the nasal symptoms. Data of serum vitamin D levels and TNSS were analysed statistically with the Pearson correlation test.

RESULTS

It was found that the mean of serum 25(OH) vitamin D levels (9.13 ng/mL) of the AR group was significantly lower than the non-AR group (26.22 ng/mL) (P = 0.000). The vitamin D cut-off points which correlated to AR was about 12.83 ng/mL (sensitivity = 80%; specificity = 100%). A Pearson correlation test found a strong, negative correlation between vitamin D levels and TNSS (P = 0.000; r = -0.800).

CONCLUSION

There was a strong, negative correlation between serum vitamin D levels with AR and TNSS. The cut-off points of serum vitamin D levels correlated to AR were approximately12.83 ng/mL. Thus, further research needs to be conducted.

It's not just the food you eat: Environmental factors in the development of food allergies

The dramatic rise in the prevalence of food allergy and food allergy-associated anaphylaxis in the past few decades has fueled investigative interest into understanding this puzzling trend. Here, we review the question as to whether important external environmental determinants beyond dietary habits and exposure to food allergens are involved. This review will summarize our current understanding of these environment determinants, derived from the latest experimental and epidemiological research. Specifically, we will review the role of exposures that affect skin barrier function, development of a diverse microbiome, and food processing. Additional exposures of concern are insufficient sunlight, endocrine disrupting chemicals and pesticides, and use of specific pharmaceutical agents that may drive or modify the risk for food allergy. Despite limitations in the quantity and quality of research to date, many new epidemiological associations and experimental data in support of this paradigm have emerged.

VITAMIN D RECEPTOR GENE MUTATIONS AND VITAMIN D SERUM LEVELS IN ASTHMATIC CHILDREN

OBJECTIVE

To verify the relationship between polymorphisms of the vitamin D receptor gene (VDR), clinical findings, and serum vitamin D (VD) levels in asthmatics.

METHODS

A cross sectional study of 77 children aged 7 to 14 years old, who were attended at a specialized clinic. The children were divided into 3 groups: asthmatics who had been using inhaled corticosteroids (ICS) for more than one year; asthmatics who had not been using ICS; non-asthmatics, and children without allergies (according to the International Study of Asthma and Allergies in Childhood -- ISAAC). Spirometry, skin prick tests, the presence of a VDR promoter CDX2 polymorphism from an allele-specific polimerase chain reaction (PCR), exons 2 and 3 polymorphisms genotyping by PCR-SSCA (single-strand conformational analysis), total immunoglobulin E (IgE) and specific IgE to mites and grass were evaluated in these three groups. Levels of 25-hydroxyvitamin D were determined in asthmatics only.

RESULTS

The mean age of the children was 10.8±2.0 years old, 57% were male, 38 were asthmatic and using ICS, 22 were asthmatic and not using ICS, and 17 were non-asthmatic. Allergic rhinitis was present in 90% of asthmatics. Homozygous CDX2 was detected in 23% of the patients and absent in the control group (p=0.03). Lower forced expiratory volume in 1 second (FEV1%) values were observed in CDX2 homozygous asthmatics (p=0.001). Variations in the exon 2 and 3 sequences were not related to asthma or the other tests. VD deficiency or insufficiency was detected in 98% of asthmatics. There was no association between VD levels and genetic polymorphisms from exons 2 and 3.

CONCLUSIONS

There was a positive association between homozygous CDX2 polymorphism, asthma and lower FEV1% values. CDX2 is capable of modifying cell interaction between VDR and VD, and it could be associated with the prevalence of asthma, and the difficulty in controlling the disease.

Successful Treatment of Severe Atopic Dermatitis with Calcitriol and Paricalcitol in an 8-Year-Old Girl

Atopic dermatitis (AD) is a chronic inflammatory disease affecting children and adolescence. The traditional therapeutic options for AD, including emollients topically and immune modulatory agents systemically focusing on reducing skin inflammation and restoring the function of the epidermal barrier, are proven ineffective in many cases. Several studies have linked vitamin D supplementation with either a decreased risk to develop AD or a clinical improvement of the symptoms of AD patients. In this report, we present a girl with severe AD who under adequate supplementation with cholecalciferol was treated with calcitriol and subsequently with paricalcitol. She had significant improvement—almost healing of her skin lesions within 2 months, a result sustained for more than 3 years now. Because of hypercalciuria as a side effect from calcitriol therapy, treatment was continued with paricalcitol, a vitamin D analogue used in secondary hyperparathyroidism in chronic kidney disease. Calcitriol therapy may be considered as a safe and efficacious treatment option for patients with severe AD, particularly for those with refractory AD, under monitoring for possible side effects. Treatment with paricalcitol resolves hypercalciuria, is safe, and should be further investigated as an alternative treatment of atopic dermatitis and possibly other diseases of autoimmune origin.

Cellular and molecular mechanisms of vitamin D in food allergy

Food allergies are becoming increasingly prevalent, especially in young children. Epidemiological evidence from the past decade suggests a role of vitamin D in food allergy pathogenesis. Links have been made between variations in sunlight exposure, latitude, birth season and vitamin D status with food allergy risk. Despite the heightened interest in vitamin D in food allergies, it remains unclear by which exact mechanism(s) it acts. An understanding of the roles vitamin D plays within the immune system at the cellular and genetic levels, as well as the interplay between the microbiome and vitamin D, will provide insight into the importance of the vitamin in food allergies. Here, we discuss the effect of vitamin D on immune cell maturation, differentiation and function; microbiome; genetic and epigenetic regulation (eg DNA methylation); and how these processes are implicated in food allergies.

ASTHMA - comparing the impact of vitamin D versus UVR on clinical and immune parameters

The incidence of asthma has increased markedly since the 1960s and is currently estimated to affect more than 300 million individuals worldwide. A number of environmental factors are implicated in asthma pathogenesis, one of which is vitamin D. Vitamin D deficiency is a global health concern and has increased in parallel with asthma incidence. Epidemiological studies report associations between low vitamin D status, assessed as circulating levels of 25-hydroxyvitamin D, with asthma incidence, severity, exacerbations and responses to treatment. This has led to clinical studies to test whether increasing the levels of vitamin D improves asthma management. Despite being highly variable in dosing regimens, design and outcomes, meta-analyses suggest overall positive outcomes with respect to reduced asthma exacerbations and steroid requirements. The primary mechanism for increasing vitamin D levels in the body is through exposure of the skin to the ultraviolet B (UVB) component of ultraviolet radiation (UVR), most commonly from sun exposure. However, only a limited number of studies investigating the impact of UVR on the asthmatic response have been performed; these generally report on the impact of latitude as a surrogate of sun exposure, or address this in animal models. To the best of our knowledge no comprehensive trials to assess the impact of UVB radiation on asthma outcomes have been performed. Within this review we discuss observational and clinical studies in this field, and innate and adaptive immune mechanisms through which UVR and vitamin D may impact respiratory health, and asthma. We highlight the heterogeneity of asthmatic disease, which is likely to impact upon the efficacy of interventional studies, and briefly overview more recent findings relating to the impact of vitamin D/UVR on the development of asthma.

Role of Vitamin D Beyond the Skeletal Function: A Review of the Molecular and Clinical Studies

The classical function of Vitamin D, which involves mineral balance and skeletal maintenance, has been known for many years. With the discovery of vitamin D receptors in various tissues, several other biological functions of vitamin D are increasingly recognized and its role in many human diseases like cancer, diabetes, hypertension, cardiovascular, and autoimmune and dermatological diseases is being extensively explored. The non-classical function of vitamin D involves regulation of cellular proliferation, differentiation, apoptosis, and innate and adaptive immunity. In this review, we discuss and summarize the latest findings on the non-classical functions of vitamin D at the cellular/molecular level and its role in complex human diseases.

Comparison of 1α-25-dihydroxyvitamin D3 and IgE Levels between Allergic Rhinitis Patients and Healthy People

Introduction  Allergic rhinitis is one of the most common allergic diseases that cause a decrease in quality of life. Over the last decades, the increase in the number of cases is supposed to be a result of industrialization and lifestyle changes. Vitamin D, which is a steroid hormone, has a significant immunomodulatory and antioxidant role in the human body.

Objective  The objective of the present study is to investigate the role of 1α-25-dihydroxyvitamin D3 levels in allergic rhinitis patients and to compare them to the levels found in the healthy population.

Methods  A total of 256 participants were included in the present study. Allergic rhinitis is diagnosed with the help of the Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines confirmed through skin prick tests. Control subjects were selected among people without allergy history, which was also confirmed through skin prick tests. The levels of 1α-25-dihydroxyvitamin D3, immunoglobulin E (IgE), and eosinophil counts were measured in blood samples from both groups.

Results  The mean value of serum levels of 1α-25-hydroxyvitamin D3 was 25.5 ± 3.74 in the allergic rhinitis group, and 31.58 ± 3.85 in the control subjects. This difference reveals statistically-decreased levels in the allergic rhinitis group ( p  < 0.05). The total IgE levels are increased in the allergic rhinitis group ( p  < 0.05) and negatively correlated with the serum levels of 1α-25-hydroxyvitamin D3 (r = - 0.259, p  < 0.05).

Conclusion  Lower serum levels of 1α-25-hydroxyvitamin D3 were detected in the allergic rhinitis population. This data is also correlated to the IgE response in the study group. A supplement of 1α-25-hydroxyvitamin D3 in deficient patients might be helpful to relieve symptoms and signs of allergic rhinitis, but further studies are needed.

Vitamin D in pediatric age: consensus of the Italian Pediatric Society and the Italian Society of Preventive and Social Pediatrics, jointly with the Italian Federation of Pediatricians

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur.Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.