The Association of Prenatal Vitamin D Sufficiency With Aeroallergen Sensitization and Allergic Rhinitis in Early Childhood

Vitamin D level is inversely related to allergen sensitization for risking atopic dermatitis in early childhood

Background

There are few studies concerning the impact of serum vitamin D status on the risk of allergen sensitization and atopic dermatitis (AD) during early childhood.

Method

Children with AD and age-matched healthy controls (HC) were prospectively enrolled at age 0.5, 2, and 4 years. Serum 25-hydroxyvitamin D (25[OH]D) level was measured using Elecsys Vitamin D Total assay. The study utilized the ImmunoCAP assay to analyze specific IgE for food and inhalant allergens, along with total serum IgE levels. It explored the connection between vitamin D levels and allergen sensitization, as well as their influence on AD at different ages.

Results

A total of 222 children including 95 (59 AD and 36 HC), 66 (37 AD and 29 HC), and 61 (32 AD and 29 HC) children were classified at age 0.5, 2, and 4 years, respectively. In children with AD, there was a significantly lower vitamin D level at age 2 and 4, but a significantly higher prevalence of food and mite sensitization at all ages in comparison with HC (P < 0.001). Vitamin D level was found to be inversely related to the prevalence of allergen sensitization at age 4 (P < 0.05). However, vitamin D level appeared to have high importance for allergen sensitization at all ages and AD at age 2 and 4 years.

Conclusion

Vitamin D deficiency is strongly associated with heightened prevalence of allergen sensitization, potentially increasing the susceptibility to AD in early childhood.

Association of Prenatal Maternal and Infant Vitamin D Supplementation with Offspring Asthma

Rationale: The role and timing of vitamin D supplementation in the prevention of asthma has not been fully elucidated. Objective: To describe the association between prenatal and postnatal vitamin D with offspring asthma outcomes in participants of the Vitamin D Antenatal Asthma Reduction Trial. Methods: We classified 748 mother-offspring pairs into four groups based on the mother's randomization to receive high-dose versus low-dose (4,400 IU vs. 400 IU) vitamin D supplementation during pregnancy and the offspring parent-reported high-dose versus low-dose (⩾400 IU vs. <400 IU) vitamin D supplementation as estimated by intake of vitamin D drops or infant formula. We used logistic regression to test the association of the four vitamin D exposure groups-"mother-low/infant-low (reference)," "mother-high/infant-high," "mother-high/infant-low," and "mother-low/infant-high"-with offspring asthma and/or recurrent wheeze at age 3 years, active asthma at age 6 years, and atopic asthma at age 6 years. Results: The risk of asthma and/or recurrent wheeze at 3 years was lowest in the mother-high/infant-low group (adjusted odds ratio vs. mother-low/infant-low, 0.39; 95% confidence interval, 0.16-0.88, P = 0.03). When stratifying by history of exclusive breastfeeding until age 4 months, the protective effect in the mother-high/infant-low group was seen only among exclusively breastfed infants (odds ratio vs. mother-low/infant-low, 0.19; 95% confidence interval, 0.04-0.68; P = 0.02). We did not observe any significant associations with active or atopic asthma at age 6 years. Conclusions: We observe that high-dose prenatal and low-dose postnatal vitamin D supplementation may be associated with reduced offspring asthma or recurrent wheeze by age 3 years, but this association may be confounded by the protective effect of breastfeeding.

Growing Up in Singapore with allergies - Lessons learnt from the GUSTO & S-PRESTO cohorts

Healthcare systems across the world face major challenges due to allergic diseases, known to affect people of all ages. In Singapore, two prominent cohort studies, Growing Up in Singapore Towards healthy Outcomes (GUSTO) and the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO), have made notable advancements to our knowledge and understanding of allergic diseases. These cohorts, which comprised of healthy mother-infant dyads recruited from the healthy Singapore population, have shed light on the complex connections between factors influencing health in early life, preconception and pregnancy, on the pathogenesis of allergic disorders in offspring. GUSTO highlighted significant risk factors in antenatal and early life, such as maternal diet, health and lifestyle choices, as well as infant environmental influences, that contributed to the risk of allergic diseases in the Asian Singaporean population. It also identified differential patterns of allergic disease in comparison to other populations, particularly the role of the microbiome in predicting atopic outcomes. Meanwhile, S-PRESTO further explores the long-term maternal and child outcomes associated with preconception health. Findings seem to suggest that prevention of offspring allergic conditions can be achieved through optimizing maternal health and lifestyle choices before conception. Both studies underscore the significance of early life interventions, preconception health, and personalized approaches to effectively manage and prevent allergies. By leveraging the insights and promising findings from GUSTO and S-PRESTO, future work can drive development of preventative strategies and personalized interventions to reduce burden of allergic diseases in the Singapore population.

Maternal Dietary Vitamin D Intake during Pregnancy Is Associated with Allergic Disease Symptoms in Children at 3 Years Old: The Japan Environment and Children's Study

INTRODUCTION

Vitamin D plays an important role in the immune system, and postnatal vitamin D insufficiency is one of the risk factors for the development of allergic disease. However, the effects of women's vitamin D intake during pregnancy on the prevalence of allergic disease in their children remain controversial.

METHODS

From the Japan Environment and Children's Study, an ongoing nationwide birth cohort study, we obtained information on maternal dietary vitamin D intake determined using a food frequency questionnaire and parent-reported allergic disease symptoms based on the ISAAC questionnaire in children at 3 years of age.

RESULTS

From the full dataset of 103,060 pregnancies, we analyzed complete data for 73,309 mother-child pairs. The prevalence of current wheeze, current rhinitis, current rhino-conjunctivitis, current eczema, ever asthma, ever pollinosis, and ever atopic dermatitis in the children was 17.2%, 29.7%, 3.8%, 15.2%, 9.6%, 3.7%, and 11.0%, respectively. The ORs for current rhinitis were significantly lower in the 3rd, 4th, and 5th quintiles than in the 1st quintile after adjustment for various covariates and showed a linear association. The ORs for ever pollinosis were significantly lower in the 2nd, 3rd, and 4th quintiles than in the 1st quintile, showing a U-shaped curve. There was no clear association between mothers' dietary vitamin D intake and symptoms of asthma or atopic dermatitis in their 3-year-old children.

CONCLUSION

Maternal dietary vitamin D intake during pregnancy is associated with the ORs for nasal allergies in children at the age of 3 years. Further studies are warranted to evaluate the appropriate intake dose of vitamin D for pregnant women to prevent the development of nasal allergies in their children.

The global/local (limited to some regions) effect of cesarean delivery on the risk of pediatric allergic rhinitis: a systematic review and meta-analysis

Background

Allergic rhinitis is a chronic and refractory disease that can be affected by a variety of factors. Studies have shown an association between cesarean section and the risk of pediatric allergic rhinitis.

Methods

The PubMed, Springer, Embase, Cochrane Library, and Web of Science databases were searched to retrieve all studies published from January 2000 to November 2022, focusing on the relationship between cesarean section and the risk of pediatric allergic rhinitis. A meta-analysis was conducted to find a correlation between cesarean section and the risk of pediatric allergic rhinitis. A subgroup analysis was performed, considering the region and family history of allergy, after adjusting for confounding factors. Pooled odds ratios (ORs) were calculated, publication bias was assessed using a funnel plot, and heterogeneity between study-specific relative risks was taken into account.

Results

The results showed that cesarean section was significantly associated with an increased risk of pediatric allergic rhinitis (OR: 1.27, 95% CI: 1.20-1.35). Subgroup analysis stratified by region indicated that cesarean section increased the risk of pediatric allergic rhinitis, with the highest increase in South America (OR: 1.67, 95% CI: 1.10-2.52) and the lowest in Europe (OR: 1.13, 95% CI: 1.02-1.25). The results of the subgroup analysis stratified by family history of allergy indicate that family history of allergy was not associated with the risk of pediatric allergic rhinitis.

Conclusion

An association exists between cesarean section as the mode of delivery and the increased risk of pediatric allergic rhinitis, and cesarean section is a risk factor for allergic rhinitis.

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

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

Lack of iron, zinc, and vitamins as a contributor to the etiology of atopic diseases

Micronutritional deficiencies are common in atopic children suffering from atopic dermatitis, food allergy, rhinitis, and asthma. A lack of iron, in particular, may impact immune activation with prolonged deficiencies of iron, zinc, vitamin A, and vitamin D associated with a Th2 signature, maturation of macrophages and dendritic cells (DCs), and the generation of IgE antibodies. In contrast, the sufficiency of these micronutrients establishes immune resilience, promotion of regulatory cells, and tolerance induction. As micronutritional deficiencies mimic an infection, the body's innate response is to limit access to these nutrients and also impede their dietary uptake. Here, we summarize our current understanding of the physiological function of iron, zinc, and vitamins A and D in relation to immune cells and the clinical consequences of deficiencies in these important nutrients, especially in the perinatal period. Improved dietary uptake of iron is achieved by vitamin C, vitamin A, and whey compounds, whereas zinc bioavailability improves through citrates and proteins. The addition of oil is essential for the dietary uptake of beta-carotene and vitamin D. As for vitamin D, the major source comes via sun exposure and only a small amount is consumed via diet, which should be factored into clinical nutritional studies. We summarize the prevalence of micronutritional deficiencies of iron, zinc, and vitamins in the pediatric population as well as nutritional intervention studies on atopic diseases with whole food, food components, and micronutrients. Dietary uptake via the lymphatic route seems promising and is associated with a lower atopy risk and symptom amelioration. This review provides useful information for clinical studies and concludes/emphasizes that a healthy, varied diet containing dairy products, fish, nuts, fruits, and vegetables as well as supplementing foods or supplementation with micronutrients as needed is essential to combat the atopic march.

Serum 25-hydroxyvitamin D deficiency is associated with atopy, and sex may be an effect modifier of its association with asthma in teenagers from northeast Brazil

OBJECTIVE

Sufficient vitamin D (25-hydroxyvitamin D [25(OH)D]) serum levels are associated with decreased asthma symptoms. Our aim was to investigate associations between vitamin D and atopy, asthma, asthma severity, and asthma phenotypes in Brazilian teenagers.

METHODS

This cross-sectional study involved 942 individuals (11-19 years old) engaged in an asthma cohort. The ISAAC questionnaire was employed to diagnosis asthma and asthma severity. Serum allergen-specific immunoglobulin E (sIgE) was measured by ImmunoCap and serum 25(OH)D was measured by ELISA. We calculated the correlation between sIgE and 25(OH)D. We used multivariate logistic regression analysis to assess associations of interest.

RESULTS

We found that 25(OH)D deficiency was positively associated with atopy (OR 1.45, confidence interval [CI] 1.05-2.00) and high levels of this vitamin negatively correlated with sIgE to Dermatophagoides pteronyssinus (r = -0.11, p = 0.019). The average 25(OH)D serum level was 27.0 ± 9.5 ng/ml; 366 individuals (38.8%) had a sufficient level. There was no association between 25(OH)D and asthma, asthma severity or asthma phenotypes in the population. However, sex was a possible effect modifier of the association between vitamin D and asthma: insufficiency in asthmatic women (86%) was higher than in asthmatic men (42%), and there was an association between insufficient vitamin D levels and greater asthma risk only in women (OR = 3.06, 95% CI 1.16-8.07).

CONCLUSION

We have shown that vitamin D deficiency was associated with greater risk of atopy in both sexes and vitamin D insufficiency was associated with asthma only in women. There was no association between vitamin D levels and asthma phenotypes or asthma severity.

Breastfeeding and vitamin D

The recent re-emergence of vitamin D deficiency (VDD) and rickets among breastfed infants without adequate sunlight exposure and vitamin D supplementation has been reported worldwide. Breastfed infants are particularly vulnerable to VDD because of the low vitamin D content of breast milk, restricted sunlight exposure, increased pollution, and limited natural dietary sources of vitamin D. The prevalence of VDD in breastfed infants differs vastly between studies and nations at 0.6%-91.1%. The recommended intake of vitamin D for lactating mothers to optimize their overall vitamin D status and, consequently, of their breast milk is 200-2,000 IU/day, indicating a lack of consensus. Some studies have suggested that maternal high-dose vitamin D supplementation (up to 6,400 IU/day) can be used as an alternate strategy to direct infant supplementation. However, concern persists about the safety of maternal high-dose vitamin D supplementation. Direct infant supplementation is the currently available option to support vitamin D status in breastfed infants. The recommended dose for vitamin D supplementation in breastfed infants according to various societies and organizations worldwide is 200-1,200 IU/day. Most international guidelines recommend that exclusively or partially breastfed infants be supplemented with 400 IU/day of vitamin D during their first year of life. However, domestic studies on the status and guidelines for vitamin D in breastfed infants are insufficient. This review summarizes the prevalence of VDD in breastfed infants, vitamin D content of breast milk, and current guidelines for vitamin D supplementation of lactating mothers and infants to prevent VDD in breastfed infants.

MicroRNA-214-3p facilitates M2 macrophage polarization by targeting GSK3B

Allergic rhinitis (AR) is a chronic inflammatory disease of the nasal mucosa. M2 macrophage polarization can reduce inflammation and repair tissue injury during AR development. Studies have substantiated the involvement of miRNAs in AR pathogenesis. Herein, the molecular mechanism of miR-214-3p in AR development was explored. To mimic the AR environment, ovalbumin (OVA) was used to treat macrophages. MiR-214-3p and glycogen synthase kinase 3 beta (GSK3B) expression in nasal mucus tissues and macrophages was assessed by RT-qPCR. The M2 phenotypic signature of CD206 in macrophages was assessed by flow cytometry. The protein expression of GSK3B and M2 macrophage markers (ARG-1 and IL-10) was evaluated by western blotting. The correlation between miR-214-3p and GSK3B was validated by a luciferase reporter assay. We found that miR-214-3p was overexpressed in macrophages and nasal mucus tissues from AR patients. MiR-214-3p facilitated M2 polarization of macrophages upon OVA stimulation. Mechanistically, miR-214-3p targeted the GSK3B 3' untranslated region in macrophages. In addition, GSK3B was downregulated in macrophages and nasal mucus tissues from AR patients. In rescue assays, GSK3B downregulation reversed the inhibitory effects of miR-214-3p silencing on M2 polarization of macrophages treated with OVA. Overall, miR-214-3p facilitates M2 macrophage polarization by targeting GSK3B.