Vitamin D deficiency in infants aged 1 to 6 months

Prevalence of vitamin D deficiency in exclusively breastfed infants at Charoenkrung Pracharak Hospital

BACKGROUND

Vitamin D deficiency is a common problem in exclusively breastfed infants, with supplementation recommended by various international medical organizations. However, in Thailand, no advice for routine vitamin D supplementation is available. Thus, this study investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

AIM

To investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

METHODS

This descriptive observational cross-sectional study assessed 109 4-month-old infants at Charoenkrung Pracharak Hospital from May 2020 to April 2021. The 25-OH vitamin D level of the infants was measured using an electrochemiluminescence binding assay. Vitamin D deficiency was defined as 25-OH level < 20 ng/mL, with vitamin D insufficiency 20-30 ng/mL. The sun index and maternal vitamin D supplementation data were collected and analyzed using the independent t-test, univariate logistic regression, and multivariate logistic regression to identify the associated factors.

RESULTS

The prevalences of vitamin D deficiency and vitamin D insufficiency were 35.78% and 33.03%, respectively with mean serum 25-OH vitamin D levels in these two groups 14.37 ± 3.36 and 24.44 ± 3.29 ng/mL. Multivariate logistic regression showed that the main factors associated with vitamin D status were maternal vitamin D supplementation and birth weight, with crude odds ratios 0.26 (0.08-0.82) and 0.08 (0.01-0.45), respectively. The sun index showed no correlation with the 25-OH vitamin D level in exclusively breastfed infants (r = -0.002, P = 0.984).

CONCLUSION

Two-thirds of healthy exclusively breastfed infants had hypovitaminosis D. Vitamin D supplementation prevented this condition and was recommended for both lactating women and their babies.

Correlation between tear levels of vascular endothelial growth factor and vitamin D at retinopathy of prematurity stages in preterm infants

Deregulation of vascular endothelial growth factor (VEGF) levels leads to retinopathy of prematurity (ROP). Vitamin D (VIT-D) is known to regulate VEGF in an oxygen dependent manner. The purpose of this study was to correlate tear levels of VEGF and VIT-D with different ROP stages in preterm infants. In this prospective cross-sectional study, we enrolled 104 pre-term infants. They were grouped into: Group-1 (Classical ROP) and Group-2 (Aggressive ROP), which were further subdivided into Group-1A (progressing), Group-1B (regressing), Group-2A (pre-treatment), and Group-2B (post-treatment). Tear VEGF and VIT-D levels and their association with different ROP stages were assessed. Stage 1 and stage 2 had higher whereas stage 3 had lower VEGF levels in Group-1B compared to Group-1A. Stage 1 and stage 3 showed higher levels of VIT-D with no difference in stage 2 in Group-1B compared to Group-1A., Group-2B showed higher VEGF and lower VIT-D levels compared to Group-2A. Presence of a positive correlation at an early stage (stage 1) of ROP and a negative correlation at a more advanced stage (stage 3) of ROP with VIT-D and VEGF implies stage-specific distinct signaling crosstalk. These findings suggest that VIT-D supplementation may have the potential to modify the course and outcome of ROP.

Evolutionary biological perspectives on current social issues of breastfeeding and weaning

Breastfeeding and weaning are actively studied from evolutionary, medical, and social research perspectives because of their close association with infant mortality, lifetime health, and human population dynamics. Each discipline benefits from an interdisciplinary exchange of knowledge regarding the bases, processes, and consequences of these phenomena. However, current social issues related to breastfeeding and weaning have received little attention from an evolutionary biology perspective. We address this gap by reviewing current social issues related to human breastfeeding and weaning in an evolutionary framework. This approach helps build a conceptual framework with the goal of better understanding ultimate causes of or influences on these current social issues. The six social issues reviewed here fall into three categories: the spatiotemporal constraints of breastfeeding, abuse of breast milk as valuable material, and mismatch in breastfeeding practices. Some of these issues have an evolutionary basis. We analyze the structure of these social issues and discuss their possible solutions in terms of extension of the trade-off theory in evolutionary biology. Our discussion on the current social issues in breastfeeding and weaning highlights the effectiveness of an approach rooted in evolutionary theory and biological anthropology.

Impact of Maternal Vitamin D Supplementation during Breastfeeding on Infant Serum Vitamin D Levels: A Narrative Review of the Recent Evidence

Vitamin D supplementation for breastfed infants is recommended due to low levels of vitamin D in human milk and the high prevalence of vitamin D deficiency. The relationship between maternal vitamin D supplementation while breastfeeding and infant serum vitamin D levels is beginning to be described. A literature review was conducted that investigated the impact of maternal supplementation, with at least 4000 IU of vitamin D, on infant serum vitamin D levels. Inclusion criteria were publication between 2016-2022, primary research, exclusively breastfed infants, and mothers taking vitamin D supplements while breastfeeding. Exclusion criteria were publication prior to 2016, review articles, results that did not include infant serum vitamin D levels, and research using participants already included in this review. Over 90% of infants whose mothers took vitamin D supplements while breastfeeding had adequate serum vitamin D levels. The final mean serum vitamin D of all infant participants whose mothers consumed vitamin D supplementation was 66.7 nmol/L, while mean serum vitamin D in those whose mothers did not consume supplements was 33.5 nmol/L. Consumption of vitamin D supplements by lactating women exclusively breastfeeding their infants can lead to adequate serum vitamin D levels in their infants.

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.

Vitamin D Levels in Children with Recurrent Acute Tonsillitis in Jordan: A Case-Control Study

Background: Vitamin D is essential for many functions of the body. In addition to its primary function of regulating the absorption of calcium in the small intestine, its role in the immune system has recently been studied. The current study aimed to test the impact of vitamin D deficiency on the rate of recurrent acute tonsillitis in children. Methods: According to Paradise criteria, two hundred forty-two children with recurrent acute tonsillitis were recruited. A group of healthy children (n = 262) was also recruited as controls. Poisson regression was run to predict the number of tonsillitis episodes per year based on vitamin D levels. The mean vitamin D level in the study group was lower than in the control group (p < 0.0001). Poisson regression of the rate of recurrent tonsillitis and vitamin D level (OR = 0.969 (95% CI, 0.962−0.975)) showed that for every single unit increase in vitamin D level, there was a 3.1% decrease in the number of tonsillitis episodes per year (p < 0.0001). Conclusions: Vitamin D deficiency is associated with higher rates of recurrent acute tonsillitis. Future controlled trials should investigate the role of vitamin D supplementation in reducing the rate of recurrent tonsillitis.

Prevalence and Correlates of Vitamin D Deficiency in Children Aged Less than Two Years: A Cross-Sectional Study from Aseer Region, Southwestern Saudi Arabia

Background: Vitamin D is an essential nutrient for bone growth, mineralization, and other metabolic processes in the human body. Hence, insufficiency or deficiency of this vitamin can have long-term effects, particularly for children. Objectives: The aims of this study were to determine the prevalence of vitamin D deficiency in children up to 2 years of age and investigate the independent predictors of vitamin D deficiency. Methodology: This cross-sectional study was conducted among 484 children aged up to two years who were admitted to the hospital for the treatment of any acute condition from January to November 2021. Serum 25(OH)D was used to determine the level of vitamin D. The serum 25(OH)D was categorized into 3 groups: Sufficiency (>30 ng/mL), insufficiency (20−30 ng/mL), and the deficiency (<20 ng/mL). Results: Overall, vitamin D deficiency was observed in 70.5% of the children, of whom 45.9% had insufficient levels, and one-fourth (24.6%) showed deficiency. The children aged 2−12 months (infants) were more likely to be vitamin deficient compared to children aged 12 months and above. The children who lived in urban areas had a threefold increased risk of vitamin D deficiency (aOR = 3.0, 95% CI 1.78−5.08). The children who were exposed to sunlight for less than 3 days per week experienced a higher risk of developing vitamin D deficiency (aOR = 4.17, 95% CI 2.04−10.88). Children who had received only breast milk were more than two times more likely to experience vitamin D deficiency (aOR = 2.42, 95% CI 1.12−5.23) compared to their counterparts. Conclusion: Our study reveals a high prevalence of vitamin D deficiency among children aged up to two years. Infants, urban dwellers, only breastfed, and exposure to sunlight for less than three days per week were identified to be the independent risk factors for vitamin D deficiency. The results of this work call for enhancing awareness to ensure adequate levels of vitamin D for better health of the children in this region of Saudi Arabia.

Vitamin D deficiency in children with cerebral palsy: A narrative review of epidemiology, contributing factors, clinical consequences and interventions

Sufficient vitamin D levels are necessary, not only for mineralization, normal growth and development of bones, but also for the prevention of fatal chronic diseases like diabetes mellitus, metabolic syndrome and cancer. This is of particular importance in children with neuro- and musculoskeletal disorders, especially cerebral palsy (CP). CP is a heterogeneous group of childhood developmental disability disorders described by uncharacteristic posture, balance, and movement. Patients with CP are at an increased risk of vitamin D deficiency and as a result reduced bone mineral density, bone fragility, osteopenia, and rickets. The present review aims to combine and summarize available evidence, regarding the epidemiology, underlying contributing factors, clinical consequences, and treatment interventions of vitamin D deficiency in children with CP.

Vitamin D Status of Breastfed Filipino Infants Aged Less Than 6 Months in an Urban Community

PURPOSE

This study aimed to determine the serum 25-hydroxy-vitamin D (25(OH)D) status of breastfed infants less than six months old and their mothers, and factors affecting the status.

METHODS

This cross-sectional study was done on breastfed, term, Filipino infants less than six months old who were seen at local health centers and clinics in an urban area. The serum 25(OH)D levels of these infants and their mothers were determined, and their demographic data, nutritional status, sun exposure behavior, and maternal vitamin D intake were analyzed for correlation using regression models.

RESULTS

Among the 131 infants, 101 (77%) had vitamin D deficiency (VDD), which was defined as having 25(OH)D levels <37.5 nmol/L, and 13 (10%) had vitamin D insufficiency (VDI), with levels >37.5-50 nmol/L. Conversely, maternal VDD with levels <50 nmol/L was seen in 31 (24%) mothers and maternal VDI with levels 50-75 nmol/L, in 63 (48%) mothers. Infant age and maternal 25(OH)D status were independent predictors of infant VDD. Infants less than three months old were found to have a six-time increased risk of infant VDD (p=0.004). Infants who had mothers with VDD had a six-time increased risk, whereas those with maternal VDI had a four-time increased risk of infant VDD (p=0.049 and p=0.020, respectively).

CONCLUSION

Both infant and maternal VDD and VDI were seen to be highly prevalent in this tropical, urban community. Young infants and maternal VDD/VDI independently increased the risk of infant VDD, whereas lack of sun exposure of the mothers increased the risk for maternal VDI.

Vitamin D Status and Factors Associated with Vitamin D Deficiency during the First Year of Life in Preterm Infants

We aimed to investigate the changes in vitamin D levels and factors associated with vitamin D deficiency (VDD) during the first year of life in Korean preterm infants. We enrolled 333 preterm infants who were born at Kyungpook National University Children’s Hospital between March 2013 and December 2019. 25-hydroxyvitamin D (25-OHD) levels and medical records were collected at birth, 6 months, and 12 months of age. The mean gestational age was 33.4 ± 2.3 weeks and mean 25-OHD levels at birth were 18.2 ± 13.5 ng/mL. The incidence of VDD was 82.8%, 30.6%, and 27.0% at birth, 6 months, and 12 months, respectively. The incidence of severe VDD (25-OHD < 10 ng/mL) was 31.5%, 1.5%, and 0%, at birth, 6 months, and 12 months, respectively. Among infants with severe VDD, the deficiency persisted in 49.6% at 6 months, and 35.3% at 12 months. The strongest predictor of VDD during follow-up was 25-OHD concentration at birth. Vitamin D supplementation at 400 IU/day did not affect vitamin D levels during the first year of life. Therefore, it is important to prevent neonatal VDD through maternal vitamin D supplementation during pregnancy. Further research is needed to determine the optimal vitamin D supplementation dose for Korean preterm infants.

An Assessment of Risk Factors for Insufficient Levels of Vitamin D during Early Infancy

Recent evidence suggests that breastfeeding may increase the risk of vitamin D deficiency in offspring. However, it is unclear whether increased risk results from breastfeeding alone, or whether it is associated together with other risk factors. This study surveyed 208 infant–mother dyads recruited by stratified random sampling in different districts of Hong Kong. Mothers were asked to complete a questionnaire on their demographics, history of risk behavior, and feeding practices. Peripheral blood samples were collected from infants to determine their vitamin D status. Among all infant participants, 70 were vitamin D insufficient or deficient. Being breastfed, being a girl, having a multiparous mother, and the use of sun cream were found to be the strongest risk factors for vitamin D insufficiency during infancy (all p < 0.05), after mutual adjustment. The cumulative risk model displayed a dose–response pattern between the number of risk factors and the risk of vitamin D insufficiency during this period. Our findings indicate the risk profile of infants with insufficient vitamin D. Guidelines and recommendations on healthy diet and lifestyle should be provided to mothers during the early stage of pregnancy to increase the likelihood of adequate levels of vitamin D in their offspring.

Vitamin D Status in Infants during the First 9 Months of Age and its Effect on Growth and Other Biochemical Markers: A Prospective Cohort Study

Background:

Despite food fortification policies in many countries and recommendations for Vitamin D supplementation of at-risk groups, Vitamin D deficiency (VDD) and infantile rickets remain major public health challenges in many developed and developing countries.

Materials and Methods:

Ninety-six participants at birth were enrolled and followed up until 9 months of age. Serum 25OHD was estimated in cord blood at birth and at 14 ± 1 weeks of life. Seventy-seven participants were followed up at 9 months for estimation of serum 25OHD, parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium, and phosphorus. VDD was defined as serum 25OHD <15 ng/mL as per USIOM guidelines.

Results:

Serum 25OHD levels at 9 months of age (15.78 ± 8.97 ng/mL) were significantly increased in comparison to the level of 3 months of age (14.04 ± 7.10 ng/mL) and at birth (8.94 ± 2.24 ng/mL). At birth, all the participants (77) were deficient in 25OHD levels. It was found that 16/94 (17%) and 19/77 (24.7%) participants at 3 and 9 months of age, respectively, became Vitamin D sufficient without any Vitamin D supplementation. There was a significant inverse correlation between serum 25OHD and PTH concentration (r = −0.522, P < 0.001), serum 25OHD and ALP (r = −0.501, P < 0.001). It was found that reduction in serum Vitamin D level to <10.25 ng/mL results in a surge of serum PTH.

Conclusion:

VDD is common from birth to 9 months of age but incidence decreases spontaneously even without supplementation. Furthermore, a large number of babies may be falsely labeled as Vitamin D deficient with currently followed cutoffs. Hence a new cutoff for VDD needs to be established for neonates and infants.

Infants' Vitamin D Nutritional Status in the First Year of Life in Northern Taiwan

Vitamin D deficiency (VDD) and insufficiency (VDI) are common among exclusively breastfeeding infants. However, epidemiological evidence for the prevalence of VDD in infants during their first year of life in Taiwan has never been found. This trial determined the prevalence of VDD and VDI and the association between dietary vitamin D and vitamin D nutritional status in Northern Taiwan. A cross-sectional study was conducted on infants who returned to well-baby examinations from October 2012 to January 2014 in three hospitals: Shin Kong Wu Ho-Su Memorial Hospital, Taipei Medical University Hospital, and Shuang Ho Hospital. The specific vitamin D cut-off concentrations for VDD, VDI, and VDS are 25(OH)D₃ levels ≤20, 21–29, and ≥30 (ng/mL). Overall, 481 infants’ parents completed a questionnaire comprising questions related to vitamin D nutritional status, including weekly time outdoors, breastfeeding status, anthropometric measurement, and assessment of dietary intake, including milk and complementary food. The results revealed that 197 (41%) and 212 (44%) of infants in their first year of life had VDI and VDD, respectively, by the Endocrine Society guidelines. Breastfed infants had a higher prevalence of VDI (86.1%) than did mixed-fed (51.9%) and formula-fed (38.5%) infants (p < 0.001). The prevalence of VDD was 55.4% in infants aged under six months but increased to 61.6% in infants aged over six months. Infants in the VDI and VDD groups had the same anthropometrics as those in the vitamin D sufficiency (VDS) group. Our results revealed that 25(OH)D₃ had a negative correlation with the intact parathyroid hormone (iPTH) when the serum 25(OH)D₃ level ≤20 ng/mL (r = −0.21, p = 0.001). The VDS group had a higher total vitamin D intake than did the VDI and VDD groups, which was mainly obtained from infant formula. Our data revealed that dietary vitamin D intake and birth season were major indicators in predicting VDD. Lower dietary vitamin D intake and born in winter and spring significantly increased the odds ratio (OR) for VDI by 1.15 (95% CI 1.09–1.20) and 2.02 (95% CI 1.10–3.70), respectively, and that for VDD by 1.23 (95% CI 1.16–1.31) and 2.37 (95% CI 1.35–4.17) without covariates adjustment, respectively. Furthermore, ORs for VDI and VDD significantly differed after adjustment for covariates. In conclusion, the prevalence of VDI and VDD were high in infants during the first year of life. Breastfeeding infants had difficulty in obtaining sufficient vitamin D from diet. In cases where the amount of sun exposure that is safe and sufficient to improve vitamin D status is unclear, breastfed infants aged below one year old are recommended to be supplemented with vitamin D.

Do infants with cow's milk protein allergy have inadequate levels of vitamin D?

OBJECTIVE

To verify whether infants with cow's milk protein allergy have inadequate vitamin D levels.

METHODS

This cross-sectional study included 120 children aged 2 years or younger, one group with cow's milk protein allergy and a control group. The children were recruited at the pediatric gastroenterology, allergology, and pediatric outpatient clinics of a university hospital in the Northeast of Brazil. A questionnaire was administered to the caregiver and blood samples were collected for vitamin D quantification. Vitamin D levels <30ng/mL were considered inadequate. Vitamin D level was expressed as mean and standard deviation, and the frequency of the degrees of sufficiency and other variables, as proportions.

RESULTS

Infants with cow's milk protein allergy had lower mean vitamin D levels (30.93 vs.35.29ng/mL; p=0.041) and higher deficiency frequency (20.3% vs.8.2; p=0.049) than the healthy controls. Exclusively or predominantly breastfed infants with cow's milk protein allergy had higher frequency of inadequate vitamin D levels (p=0.002). Regardless of sun exposure time, the groups had similar frequencies of inadequate vitamin D levels (p=0.972).

CONCLUSIONS

Lower vitamin D levels were found in infants with CMPA, especially those who were exclusively or predominantly breastfed, making these infants a possible risk group for vitamin D deficiency.

Total Duration of Breastfeeding, Vitamin D Supplementation, and Serum Levels of 25-Hydroxyvitamin D

OBJECTIVES

To determine the association between total breastfeeding duration and serum 25-hydroxyvitamin D (25-OHD) and to explore whether vitamin D supplementation influences this association.

METHODS

We conducted a cross-sectional study of healthy children between September 2011 and August 2013 through the TARGet Kids! primary health care research network. Of the 4533 eligible children, we included only the 2508 who had 25-OHD measured. We assessed adjusted associations of total breastfeeding duration (in months) with serum 25-OHD and in supplemented versus nonsupplemented children, with the odds of 25-OHD less than 20 nanograms per milliliter.

RESULTS

Each 1-month increase in total breastfeeding duration was associated with a 0.12 nanograms per milliliter lower median serum 25-OHD (95% confidence interval [CI] = -0.21 ng/mL, -0.02 ng/mL) among children who were not supplemented. The odds of serum 25-OHD less than 20 nanograms per milliliter increased by 6% (odds ratio [OR] = 1.06; 95% CI = 1.03, 1.10) for every 1-month increase in total breastfeeding duration among nonsupplemented children. The interaction between vitamin D supplementation, duration of breastfeeding, and median serum 25-OHD was statistically significant (P = .04).

CONCLUSIONS

Breastfed children who were not supplemented, particularly those breastfed more than 1 year, appear to have lower vitamin D status. Vitamin D supplementation may mitigate this risk. These findings support recommendations for supplementation during breastfeeding of any duration.

Severe vitamin D deficiency in preterm infants: maternal and neonatal clinical features

Purpose

We investigated the vitamin D status of preterm infants to determine the incidence of vitamin D deficiency.

Methods

A total of 278 preterm infants delivered at Kyungpook National University Hospital between January 2013 and May 2015 were enrolled. The serum concentrations of calcium, phosphorous, alkaline phosphatase, and 25-hydroxyvitamin D (25-OHD) were measured at birth. We collected maternal and neonatal data such as maternal gestational diabetes, premature rupture of membranes, maternal preeclampsia, birth date, gestational age, and birth weight.

Results

Mean gestational age was 33⁺⁵±2⁺² weeks of gestation and mean 25-OHD concentrations were 10.7±6.4 ng/mL. The incidence of vitamin D deficiency was 91.7%, and 51.1% of preterm infants were classified as having severe vitamin D deficiency (25-OHD<10 ng/mL). The serum 25-OHD concentrations did not correlate with gestational age. There were no significant differences in serum 25-OHD concentrations or incidence of severe vitamin D deficiency among early, moderate, and late preterm infants. The risk of severe vitamin D deficiency in twin preterm infants was significantly higher than that in singletons (odds ratio, 1.993; 95% confidence interval [CI], 1.137-3.494, P=0.016). In the fall, the incidence of severe vitamin D deficiency decreased 0.46 times compared to that in winter (95% CI, 0.227-0.901; P=0.024).

Conclusion

Most of preterm infants (98.9%) had vitamin D insufficiency and half of them were severely vitamin D deficient. Younger gestational age did not increase the risk of vitamin D deficiency, but gestational number was associated with severe vitamin D deficiency.

Formula fed twin infants with recurrent hypocalcemic seizures with vitamin D deficient rickets and hyperphosphatemia

Vitamin D deficient rickets is generally known to occur in breast fed infants. And excessive phosphate ingestion is a main cause of late onset hypocalcemia in formula fed infants. Here we introduce 45-day-old formula fed hypocalcemic twins with recurrent seizure attacks. They were diagnosed as having both of vitamin D deficient rickets and hyperphosphatemia. Radiologic findings indicated mild rickets and the twins were treated with calcium and alfacalcidol. After 3-5 months of oral supplementation, medication was discontinued in both twins. They showed normal growth and calcium, phosphorus, and vitamin D levels during the 6-month follow-up period. Twins can be at risk for hypocalcemia because of their high risk of vitamin D deficiency, low birth weight, and premature birth. Therefore twin pregnant women need ingestion of sufficient vitamin D and calcium.

The role of Toll-like receptors and vitamin D in diabetes mellitus type 1--a review

It is widely accepted that type 1 diabetes mellitus (T1DM) is an autoimmune disease resulting from an interaction between immunologic, genetic and environmental factors. However, the exact mechanism leading to the development of T1DM remains incomplete. There is a large body of evidence pointing towards the important role of toll-like receptor (TLR) activation and vitamin D deficiency in T1DM pathogenesis. In this article, we review the available data on the influence of TLRs' level of activation and vitamin D status on the risk of the development of T1DM in humans and rodent models. We also summarize the current information regarding the interactions between TLRs' level of activation, vitamin D status and various environmental factors, such as enteroviral infections, the gut microbiota and breastfeeding substitution, among others. Our results stipulate that vitamin D seems to protect against T1DM by reducing the TLRs' level of activation.

The link between serum vitamin D level, sensitization to food allergens, and the severity of atopic dermatitis in infancy

OBJECTIVE

To investigate the association between serum vitamin D levels, sensitization to food allergens, and the severity of atopic dermatitis in infants.

STUDY DESIGN

We investigated serum 25-hydroxyvitamin D (25[OH]D) and specific immunoglobulin E levels to common or suspected food allergens in 226 infants with atopic dermatitis or food allergy. The severity of atopic dermatitis by the Scoring Atopic Dermatitis index and amount of vitamin D intake was measured in subcohort children. Sensitization to food allergen was categorized by the number (non-, mono-, and poly-) of sensitized allergens and the degree (undetected-, low-, and high-level) of sensitization.

RESULTS

Significant differences in 25(OH)D levels were found between groups on number (P = .006) and degree (P = .005) of food sensitization. The polysensitization group had significantly lower levels of 25(OH)D than the nonsensitization (P = .001) and monosensitization (P = .023) group. High-level sensitization group had significantly lower 25(OH)D levels compared with undetected (P = .005) and low-level (P = .009) sensitization group. Vitamin D deficiency increased the risk of sensitization to food allergens (OR 5.0; 95% CI 1.8-14.1), especially to milk (OR 10.4; 95% CI 3.3-32.7) and wheat (OR 4.2; 95% CI 1.1-15.8). In addition, the Scoring Atopic Dermatitis index was independently related to 25(OH)D levels after adjusting for the level of sensitization (adjusted R(2) = 0.112, P = .031).

CONCLUSIONS

Our results suggest that vitamin D deficiency increases the risk of sensitization to food allergens and that atopic dermatitis may be more severe in infants with vitamin D deficiency.