Vitamin D and iron status in children with food allergy

Dairy consumption and vitamin D concentration in adolescents with challenge-confirmed cow's milk allergy during infancy

BACKGROUND/OBJECTIVES

Milk is an important source of dietary calcium and, if fortified, vitamin D. Cow's milk allergy (CMA) is treated with a milk elimination diet. Although most children become tolerant by age 3 years, some continue dairy avoidance. It remains unclear whether adolescents with a history of CMA adopt similar milk consumption as their peers. We assessed dairy consumption and concentration of serum 25-hydroxyvitamin D (25(OH)D) in adolescents with either confirmed CMA or a negative CMA challenge in infancy (CMA-refuted group) and age-matched controls.

SUBJECTS/METHODS

This study is based on a previously reported randomized controlled trial from 1999 to 2002 on the treatment effect of probiotics on atopic eczema in participants aged <12 months (n = 230) with data on CMA status. We followed up these participants, aged 15-18 years, in 2017 (n = 104). A 20-item food frequency questionnaire assessed dairy consumption. An automated immunoassay measured 25(OH)D concentration.

RESULTS

Median dairy product consumption did not differ between adolescents with CMA (449 g/d, n = 40), the CMA-refuted group (566 g/d, n = 36), and controls (235 g/d, n = 51) (P = 0.117). Median 25(OH)D concentrations were 76.0, 79.3, and 80.8 nmol/l, respectively (P = 0.844). Among participants, 93% were vitamin D sufficient (25(OH)D ≥ 50 nmol/l), with no differences between groups (P = 0.914).

CONCLUSION

Among adolescents with a history of CMA during infancy, our study found no reintroduction failure of milk and no difference in vitamin D insufficiency rate compared with peers. Current management of CMA seems to adequately minimize later nutritional disadvantages associated with a cow's milk elimination diet.

Alterations in Child Feeding Behavior: An Underrecognized Clinical Complication of Food Allergy

BACKGROUND

Food allergy (FA) affects around 5.6 million children in the United States, conferring risk for negative impacts on growth and psychosocial functioning. While evidence suggests a higher prevalence of feeding difficulties in children with FA, the link between FA and feeding dysfunction remains unclear.

OBJECTIVE

To investigate feeding problems in children with parent-reported IgE-mediated FA and/or pediatric feeding disorder (PFD) compared with healthy children in a community-based sample and explore factors associated with feeding problems in children with FA.

METHODS

A matched cross-sectional cohort study used survey data from 352 parents of children aged 6 months to 7 years who reported a diagnosed IgE-mediated FA and/or PFD (50 with FA only, 67 with FA and PFD, and 235 with PFD only). Healthy children were matched based on age, sex, race, and socioeconomic factors. Feeding problems were assessed using the Pediatric Eating Assessment Tool. Matched-pairs generalized linear regressions compared each cohort and explored factors associated with feeding problems in children with FA.

RESULTS

Children with FA exhibited significantly higher feeding problems compared with healthy children. Children with a diagnosed PFD had more severe feeding problems, irrespective of comorbid FA. Factors linked with feeding problems in children with FA included older age, non-White race, increased medical comorbidity, and limited dietary variety.

CONCLUSIONS

This study adds to evidence indicating a higher prevalence of feeding problems in children with FA. Clinicians treating FA patients should routinely screen for feeding and growth concerns and consider referral to multidisciplinary feeding programs as needed.

The potential of orally exposed risk factors and constituents aggravating food allergy: Possible mechanism and target cells

Food allergy is a significant concern for the health of humans worldwide. In addition to dietary exposure of food allergens, genetic and environmental factors also play an important role in the development of food allergy. However, only the tip of the iceberg of risk factors in food allergy has been identified. The importance of food allergy caused by orally exposed risk factors and constituents, including veterinary drugs, pesticides, processed foods/derivatives, nanoparticles, microplastics, pathogens, toxins, food additives, dietary intake of salt/sugar/total fat, vitamin D, and therapeutic drugs, are highlighted and discussed in this review. Moreover, the epithelial barrier hypothesis, which is closely associated with the occurrence of food allergy, is also introduced. Additionally, several orally exposed risk factors and constituents that have been reported to disrupt the epithelial barrier are elucidated. Finally, the possible mechanisms and key immune cells of orally exposed risk factors and constituents in aggravating food allergy are overviewed. Further work should be conducted to define the specific mechanism by which these risk factors and constituents are driving food allergy, which will be of central importance to the targeted therapy of food allergy.

Malnutrition and Allergies: Tipping the Immune Balance towards Health

Malnutrition, which includes macro- and micronutrient deficiencies, is common in individuals with allergic dermatitis, food allergies, rhinitis, and asthma. Prolonged deficiencies of proteins, minerals, and vitamins promote Th2 inflammation, setting the stage for allergic sensitization. Consequently, malnutrition, which includes micronutrient deficiencies, fosters the development of allergies, while an adequate supply of micronutrients promotes immune cells with regulatory and tolerogenic phenotypes. As protein and micronutrient deficiencies mimic an infection, the body's innate response limits access to these nutrients by reducing their dietary absorption. This review highlights our current understanding of the physiological functions of allergenic proteins, iron, and vitamin A, particularly regarding their reduced bioavailability under inflamed conditions, necessitating different dietary approaches to improve their absorption. Additionally, the role of most allergens as nutrient binders and their involvement in nutritional immunity will be briefly summarized. Their ability to bind nutrients and their close association with immune cells can trigger exaggerated immune responses and allergies in individuals with deficiencies. However, in nutrient-rich conditions, these allergens can also provide nutrients to immune cells and promote health.

Nutritional and Psychosocial Impact of Food Allergy in Pediatric Age

Treatment of IgE-mediated food allergy involves avoiding the food causing the allergic reaction. In association, an action plan for allergic reactions is indicated, sometimes including self-injectable adrenaline. In addition to these dietary and medical implications, there are two equally important ones: nutritional and psychosocial. From a nutritional point of view, it is known that children suffering from food allergy have a growth delay in height and weight compared to their non-allergic peers. Specifically, this condition is directly related to the specific food excluded from the diet, the number of foods excluded and the duration of the elimination diet. From a psychosocial point of view, the child often cannot eat the foods other guests eat. Children with food allergy may perceive an aura of parental anxiety around their mealtime and may be afraid that what they eat could have harmful consequences for their health. Furthermore, children's and their parents' quality of life appears to be affected. The need to manage the allergy and the nutritional and psychosocial problems positions the pediatric nutritionist and the child neuropsychiatrist as support figures for the pediatric allergist in managing the child with food allergy.

Physiological Evidence and Therapeutic Outcomes of Vitamin D on Cardiovascular Diseases

Vitamin D hormone is an important regulator of various physiological functions, and its deficiency is characterized by an imbalance in parathyroid hormone and calcium homeostasis. The role of vitamin D in cardiovascular physiology is well demonstrated in animal and humanbased studies. In this context, hyperlipidemia, increased atherogenic plaques, cardiac inflammation, hypertension, myocarditis, myocardial infarction, and heart failure are some of the commonest known conditions connected with vitamin D deficiency. Supplementation of vitamin D is recommended to achieve normal serum vitamin D concentrations, nonetheless, in clinical trials often seen discrepancies concerning the supplementation effects and effectiveness. This review summarizes the data on the role of vitamin D in cardiovascular health along with some recent clinical findings regarding the effects of vitamin D supplementation.

Growth and Nutritional Biomarkers in Brazilian Infants with Cow's Milk Allergy at Diagnosis and 18-Month Follow-Up: A Prospective Cohort Study

Purpose

This study aimed to describe the growth, body protein status, and micronutrient biomarkers of Brazilian infants with cow's milk allergy (CMPA) at baseline and at 18 months of follow-up in comparison with their healthy peers.

Methods

Thirty infants with CMPA younger than six months of age were included in this longitudinal study, and their nutritional status was compared with that of 24 non-allergic age-matched children. Anthropometric measurements were used to assess growth, and blood and urine samples were analyzed for protein and micronutrient status. Mixed linear models adjusted for birth weight, socioeconomic status, infant feeding at baseline, weight-for-age, C-reactive protein, serum albumin, micronutrient dietary supplementation, and salt consumption were employed to evaluate the evolution of nutritional parameters throughout the follow-up period.

Results

Overall, the mean age of the children at enrolment was 2.9 (standard deviation 1.7) months, and 29 children (53.7%) were male. Infants with CMPA showed a higher prevalence of functional iron depletion (transferrin saturation <20) (p=0.027), lower serum ferritin (p=0.009), and lower urinary iodine (p=0.034) levels than non-allergic children at baseline. Patients with CMPA showed a higher increment in weight-for-age and length-for-age over time than those in the control group (p<0.01). Mixed linear analyses showed a significantly lower increase in serum vitamin B12 (s-B12) (p=0.001) and urinary iodine (p<0.001) concentrations over time compared to the control group.

Conclusion

Infants with CMPA on a cow's milk elimination diet had a higher weight and length at 18 months of follow-up but showed signs of inadequate iron, iodine, and B-12 vitamin status.

Nutritional Status of Children with Newly Diagnosed Food Allergies

BACKGROUND

Most published pediatric guidelines on food allergy highlight the importance of nutritional counseling and dietary adequacy to avoid either growth retardation or nutritional deficiencies. The aim of the study was an assessment of the nutritional status of children with IgE-mediated food allergies.

MATERIAL AND METHOD

45 patients with newly diagnosed food allergy (FA) and 33 healthy controls were analyzed (aged 6 to 72 months, 60.2% boys). The nutritional status was assessed using anthropometric measurements (body weight and length) and serum laboratory tests. The results were analyzed with the Statistica 12 software (Tulsa, OK, USA).

RESULTS

82%, 40%, 8.8%, and 6.6% of the studied children demonstrated allergy to hen's egg, cow's milk, pork meat, and wheat/rye, respectively. Z-score BMI < -2SD was more often found in the FA subjects under 30 months of age than in the controls (p = 0.04). As many as 77.8% of the FA subjects and 78.8% of the controls were of normal height (hSDS: -0.23 ± 1.74 and -0.31 ± 1.49, respectively, p = 0.8). Retinol binding protein four serum concentration was significantly lower in the FA group (17.01 ± 3.84 mg/L) than in the controls (20.47 ± 4.87 mg/L, p < 0.001). No statistically significant differences were observed between the FA group and the controls (either in the younger or the older age group) (p > 0.05) for the serum concentrations of total protein, total cholesterol, thyroxin-binding prealbumin (TBPA), 25(OH)D, hemoglobin level or white blood cells.

CONCLUSIONS

In patients under 30 months of age, one of the symptoms of food allergy may be body weight deficiency, while short stature is less common at the time of diagnosis.

Immunologic, genetic, and ecological interplay of factors involved in allergic diseases

An allergic or type I hypersensitivity reaction involves a misdirected immune overreaction to innocuous environmental and dietary antigens called allergens. The genetic predisposition to allergic disease, referred to as atopy, can be expressed as a variety of manifestations-e.g., allergic rhinitis, allergic conjunctivitis, atopic dermatitis, allergic asthma, anaphylaxis. Globally, allergic diseases are one the most common types of chronic conditions. Several factors have been identified to contribute to the pathogenesis and progression of the disease, leading to distinctively variable clinical symptoms. The factors which can attenuate or exacerbate allergic reactions can range from genetic heterozygosity, the prominence of various comorbid infections, and other factors such as pollution, climate, and interactions with other organisms and organism-derived products, and the surrounding environment. As a result, the effective prevention and control of allergies remains to be one of the most prominent public health problems. Therefore, to contextualize the current knowledge about allergic reactions, this review paper attempts to synthesize different aspects of an allergic response to describe its significance in the global health scheme. Specifically, the review shall characterize the biomolecular mechanisms of the pathophysiology of the disease based on underlying disease theories and current findings on ecologic interactions and describe prevention and control strategies being utilized. An integrated perspective that considers the underlying genetic, immunologic, and ecologic aspects of the disease would enable the development of more effective and targeted diagnostic tools and therapeutic strategies for the management and control of allergic diseases.

Beyond allergic progression: From molecules to microbes as barrier modulators in the gut-lung axis functionality

The "epithelial barrier hypothesis" states that a barrier dysfunction can result in allergy development due to tolerance breakdown. This barrier alteration may come from the direct contact of epithelial and immune cells with the allergens, and indirectly, through deleterious effects caused by environmental changes triggered by industrialization, pollution, and changes in the lifestyle. Apart from their protective role, epithelial cells can respond to external factors secreting IL-25 IL-33, and TSLP, provoking the activation of ILC2 cells and a Th2-biased response. Several environmental agents that influence epithelial barrier function, such as allergenic proteases, food additives or certain xenobiotics are reviewed in this paper. In addition, dietary factors that influence the allergenic response in a positive or negative way will be also described here. Finally, we discuss how the gut microbiota, its composition, and microbe-derived metabolites, such as short-chain fatty acids, alter not only the gut but also the integrity of distant epithelial barriers, focusing this review on the gut-lung axis.

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.

Ultra-processed foods and allergic symptoms among children and adults in the United States: A population-based analysis of NHANES 2005-2006

Design

There is a strong correlation between dietary intake and allergic diseases. Ultra-processed foods (UPFs) are gradually becoming dominant worldwide and causing health problems for children and adults. We hope to determine whether links exist between UPFs and allergic symptoms.

Methods

We investigated data from 2,736 children (16-19 years) and 4,256 adults (≥20 years) from the National Health and Nutritional Examination Survey (NHANES) 2005-2006. The associations between the mean UPFs contribution to total energy intake and all allergic symptoms (IgE, current asthma, allergy, rash, sneeze, wheeze, eczema, and hay fever) were estimated by weighted multivariate logistic regression.

Results

Logistic regression analysis showed UFPs were negatively associated with IgE levels in children. Those with higher quartiles had a reduced risk from 16% (OR, 0.84, 95%CI, 0.55 to 1.28) to 34% (OR, 0.66, 95%CI, 0.49 to 0.89), p for trend = 0.006. UPFs were also positively related to current asthma in children with an increased risk of 11% (OR, 1.11, 95%CI, 0.79 to 1.56) to 76% (OR, 1.76, 95%CI, 1.10 to 2.82), p for trend = 0.0393. UPFs were also associated with eczema in girls. But there was no association observed between UPFs and allergic symptoms in adults.

Conclusion

Our results suggested that UPFs assessed by the NOVA system were associated with IgE, current asthma in children, and eczema in girls. These results further support the need to test the association of modern dietary patterns with allergic symptoms.

The Crosstalk between Vitamin D and Pediatric Digestive Disorders

Vitamin D is a cyclopentane polyhydrophenanthrene compound involved mainly in bone health and calcium metabolism but also autophagy, modulation of the gut microbiota, cell proliferation, immune functions and intestinal barrier integrity. The sources of vitamin D include sunlight, diet and vitamin D supplements. Vitamin D3, the most effective vitamin D isoform is produced in the human epidermis as a result of sunlight exposure. Vitamin D undergoes two hydroxylation reactions in the liver and kidney to reach its active form, 1,25-dihydroxyvitamin D. Recent studies highlighted a complex spectrum of roles regarding the wellbeing of the gastrointestinal tract. Based on its antimicrobial effect, it was recently indicated that vitamin D supplementation in addition to standard eradication therapy might enhance H. pylori eradication rates. Moreover, it was suggested that low levels of vitamin D might also be involved in the acquisition of H. pylori infection. In terms of celiac disease, the negative effects of vitamin D deficiency might begin even during intrauterine life in the setting of maternal deficiency. Moreover, vitamin D is strongly related to the integrity of the gut barrier, which represents the core of the pathophysiology of celiac disease onset, in addition to being correlated with the histological findings of disease severity. The relationship between vitamin D and cystic fibrosis is supported by the involvement of this micronutrient in preserving lung function by clearing airway inflammation and preventing pathogen airway colonization. Moreover, this micronutrient might exert anticatabolic effects in CF patients. Inflammatory bowel disease patients also experience major benefits if they have a sufficient level of circulating vitamin D, proving its involvement in both induction and remission in these patients. The findings regarding the relationship between vitamin D, food allergies, diarrhea and constipation remain controversial, but vitamin D levels should be monitored in these patients in order to avoid hypo- and hypervitaminosis. Further studies are required to fill the remaining gaps in term of the complex impact of vitamin D on gastrointestinal homeostasis.

Iron-Deficiency in Atopic Diseases: Innate Immune Priming by Allergens and Siderophores

Although iron is one of the most abundant elements on earth, about a third of the world's population are affected by iron deficiency. Main drivers of iron deficiency are beside the chronic lack of dietary iron, a hampered uptake machinery as a result of immune activation. Macrophages are the principal cells distributing iron in the human body with their iron restriction skewing these cells to a more pro-inflammatory state. Consequently, iron deficiency has a pronounced impact on immune cells, favoring Th2-cell survival, immunoglobulin class switching and primes mast cells for degranulation. Iron deficiency during pregnancy increases the risk of atopic diseases in children, while both children and adults with allergy are more likely to have anemia. In contrast, an improved iron status seems to protect against allergy development. Here, the most important interconnections between iron metabolism and allergies, the effect of iron deprivation on distinct immune cell types, as well as the pathophysiology in atopic diseases are summarized. Although the main focus will be humans, we also compare them with innate defense and iron sequestration strategies of microbes, given, particularly, attention to catechol-siderophores. Similarly, the defense and nutritional strategies in plants with their inducible systemic acquired resistance by salicylic acid, which further leads to synthesis of flavonoids as well as pathogenesis-related proteins, will be elaborated as both are very important for understanding the etiology of allergic diseases. Many allergens, such as lipocalins and the pathogenesis-related proteins, are able to bind iron and either deprive or supply iron to immune cells. Thus, a locally induced iron deficiency will result in immune activation and allergic sensitization. However, the same proteins such as the whey protein beta-lactoglobulin can also transport this precious micronutrient to the host immune cells (holoBLG) and hinder their activation, promoting tolerance and protecting against allergy. Since 2019, several clinical trials have also been conducted in allergic subjects using holoBLG as a food for special medical purposes, leading to a reduction in the allergic symptom burden. Supplementation with nutrient-carrying lipocalin proteins can circumvent the mucosal block and nourish selectively immune cells, therefore representing a new dietary and causative approach to compensate for functional iron deficiency in allergy sufferers.

Correlation between vitamin D levels and bone metabolism in children with cow's milk allergy

Objective

Research is limited regarding biochemical markers of bone metabolism among children with cow’s milk protein allergy (CMPA). We aimed to determine differences in vitamin D and bone metabolism markers between infants with CMPA and healthy infants and explore relationships between these in a cross-sectional study.

Methods

In total, we included 41 children diagnosed with CMPA and under systematic medical and nutritional care at our center, and 50 healthy children as a control group. We reviewed demographic and clinical characteristics and measured serum biomarkers.

Results

We found that serum 25-hydroxyvitamin D (25(OH)D) levels among infants in the CMPA group were significantly lower than those in the control group, and levels of bone-specific alkaline phosphatase (BALP), serum phosphorus, and serum calcitonin were reduced. Pearson correlation analysis showed that serum 25(OH)D concentrations in the CMPA group were negatively correlated with parathyroid hormone but not significantly correlated with calcitonin and BALP. Logistic regression showed that CMPA was a risk factor for vitamin D deficiency.

Conclusions

Our study indicated that CMPA was associated with disturbances in bone metabolism. Levels of vitamin D in children with CMPA were lower than those in healthy children. CMPA was a risk factor for vitamin D deficiency.

Vitamin D Levels in Asymptomatic Children and Adolescents with Atopy during the COVID-19 Era

This study assessed vitamin D status in asymptomatic children and adolescents in Greece, with and without atopy, and possible changes during the coronavirus disease 2019 (COVID-19) pandemic. Serum levels of 25-hydroxy-vitamin D (25(OH)D) and total immunoglobulin E (IgE), and eosinophil count were measured in 340 asymptomatic children and adolescents (155 males, 185 females), mean age 8.6 ± 4.6 years, recruited over a period of 24 months (February 2019–January 2021). Atopy, defined by high level of IgE for age, was associated with vitamin D deficient status (p = 0.041). Subjects with and without atopy showed similar rates of insufficient and normal levels of 25(OH)D. The median level of 25(OH)D was significantly higher in subjects recruited during the pandemic, when home confinement rules were observed, than before the pandemic, and significantly more children had normal levels of 25(OH)D (p < 0.001), but no differences were noticed for IgE levels or eosinophil count. These results support a link between vitamin D and allergic and infectious inflammations, and specifically the association of vitamin D deficiency with asymptomatic atopy, defined as increased IgE level for age.