Evaluating the effects of vitamin D Level on airway obstruction in two asthma endotypes in humans and in two mouse models with different intake of vitamin D during early-life

Serum Vitamin D Profiles of Children with Asthma in Southwest Saudi: A Comparative Cross-Sectional Study

Background

Evidence suggests a strong association between vitamin D status and asthma, with individuals exhibiting vitamin D deficiency demonstrating increased prevalence and severity of asthma symptoms. This study aimed to determine the prevalence of vitamin D deficiency among asthmatic children, assess the association between vitamin D status and asthma severity/control, and identify potential predictors of vitamin D deficiency in this population.

Patients and Methods

This comparative cross-sectional, hospital-based study was conducted at Abha Maternity and Children's Hospital, a tertiary care and teaching institution in southwestern Saudi Arabia, between January 2023 and May 2024.

Results

A total of 331 asthmatic children and 101 non-asthmatic children were analyzed. Children with asthma had significantly lower serum vitamin D levels than those without asthma (21.5 ± 8.8 ng/mL vs 33.3 ± 13.2 ng/mL, p < 0.001). Significantly higher proportions of asthmatic children exhibited vitamin D deficiency (51.1%) and insufficiency (34.7%) compared to non-asthmatic children (19.8% and 29.7%, respectively). Serum vitamin D levels among asthmatic children showed significant negative correlations with age (r = -0.332, p < 0.001), weight (r = -0.292, p < 0.001), height (r = -0.298, p < 0.001), and BMI (r = -0.274, p < 0.001). These findings were further supported by univariate linear regression analysis. Multivariable analysis additionally confirmed age (β = -0.66, p < 0.001) and BMI (β = -0.25, p = 0.05) as independent predictors of vitamin D status, with older age and higher BMI associated with lower vitamin D levels. For each additional year of age, serum vitamin D decreased by an average of 0.66 ng/mL (p < 0.001) and a one-unit increase in BMI was associated with a decrease of 0.25 ng/mL in serum vitamin D (p = 0.05).

Conclusion

This study found a strikingly high prevalence of vitamin D deficiency among asthmatic children in southwestern Saudi Arabia, significantly exceeding rates in controls. These findings underscore the need for widespread vitamin D screening and supplementation in this population, particularly among older, overweight asthmatic children.

Association between 25-hydroxy vitamin D, interleukin-4, and interferon-γ levels and asthma in children with Mycoplasma pneumonia infection

To explore the association between 25-hydroxy vitamin D [25-(OH)-D], interleukin-4 (IL-4), and interferon-γ (IFN-γ) in children with Mycoplasma pneumoniae (MP) infection-related asthma. Logistic analysis was conducted to compare general data in MP asthma and MP non-asthma groups. The level of 25-(OH)-D, IL-4, and IFN-γ were detected and compared between groups. Moreover, the receiver operating characteristic curve (ROC) was applied to test the predictive value of each variable. The results of logistic regression analysis demonstrated that recurrent upper respiratory tract infections and collective living are related to the incidence of MP infection whether with asthma or without asthma. IL-4 and IFN-γ in MP asthma group were significantly higher than those in MP non-asthma group and control group (p < 0. 05), whilst 25-(OH)-D and IFN-γ/IL-4 in MP asthma group were significantly lower than those in MP non-asthma group and control group (p < 0. 05). ROC curves indicated that the area under the curve (AUC) of 25-(OH)-D, IL-4, IFN-γ, IFN-γ/IL-4, and joint detection are 0.765, 0.780, 0.853, 0.638, and 0.912 in diagnosis of MP infection-related asthma, and sensitivity and specificity of joint detection are both greater than 95%. For children with MP infection-related asthma, the level of IL-4 and IFN-γ is upregulated, while 25-(OH)-D is downregulated. The joint detection of 25-(OH)-D, IL-4, IFN-γ, and IFN-γ/IL-4 may improve diagnostic capabilities of MP infection-related asthma.

Serum Vitamin D Level Is Unchanged in Equine Asthma

Vitamin D deficiency is associated with asthma development and severity of symptoms in humans, but whether the same occurs in horses is unknown. We aimed to determine whether the serum vitamin D levels differ in horses with asthma compared to control animals and, secondarily, to explore clinical, respiratory, and environmental parameters associated with its concentration in equids in a retrospective cross-sectional study. The total serum vitamin D (25(OH)D) was measured by radioimmunoassay in 45 serum samples from the Equine Respiratory Tissue Biobank (15 control animals, 14 horses with mild or moderate asthma (MEA), and 16 horses with severe asthma (SEA)). Descriptive clinical and environmental parameters, bronchoalveolar lavage fluid cytology, and lung function data were extracted. There was no difference in serum 25(OH)D levels between healthy controls, horses with MEA, and horses with SEA (respectively, means of 57.9 ± 11.6, 55.6 ± 20.0, and 64.6 ± 14.5 nmol/L; p = 0.3), suggesting that this micronutrient does not play a major role in equine asthma pathophysiology.

U-shaped association between 25-hydroxyvitamin D concentration and the prevalence of asthma in the overweight and obese U.S. population

INTRODUCTION

Vitamin D supplementation has shown promise in averting asthma. However, the association between 25(OH)D levels and asthma prevention in various demographic groups remains inconclusive. Here, we explore this relationship in the context of overweight and obese individuals in the United States.

METHODS

We scrutinized cross-sectional data derived from the National Health and Nutrition Examination Survey conducted between 2007 and 2018. This dataset encompasses comprehensive information about asthma patients with a body mass index greater than 25 kg/m2, in addition to data regarding 25(OH)D concentration and other pertinent variables. Among the 3889 participants, 16.2% (631/3889) reported a history of asthma, constituting 1765 (45.4%) males and 2124 (54.6%) females. The median age was 56.0 years, with a standard deviation of 16.0 years. We conducted restricted cubic spline (RCS) regression analysis to assess the correlation between 25(OH)D levels and asthma.

RESULTS

After adjusting for confounders, compared to individuals with lower 25-hydroxyvitamin D concentration (group1 ≤ 46.6 nmol/L), the adjusted odds ratios (OR) for asthma in group2 (46.7-62 nmol/L), group3 (62.1-78.2 nmol/L), and group4 (≥78.3 nmol/L) were 0.68 (95% CI: 0.49-0.94, p < 0.021), 0.65 (95% CI: 0.47-0.88, p < 0.006), and 0.83 (95% CI: 0.61-1.12, p < 0.22), respectively. Restricted cubic spline (RCS) regression analysis revealed a nonlinear U-shaped curve (p = 0.017) with an inflection point at approximately 84.95 nmol/L.

CONCLUSIONS

High levels of 25(OH)D are correlated with a diminished prevalence of asthma among overweight and obese individuals in the United States.

Vitamin D status in hospitalized COVID‑19 patients is associated with disease severity and IL-5 production

BACKGROUND

There are many studies on the relationship between vitamin D and coronavirus disease 2019 (COVID-19), while the results are matters of debate and the mechanisms remain unknown. The present study was performed to assess the impact of serum 25-hydroxyvitamin D [25(OH)D] levels on the severity of disease in hospitalized COVID-19 patients and identify potential mechanisms of 25(OH)D alterations.

METHODS

A total of 399 hospitalized COVID-19 patients were recruited from three centers between December 19, 2022, and February 1, 2023. Medical history, laboratory examination, and radiologic data were retrospectively collected. The patients were divided into four groups based on disease severity. Serum 25(OH)D levels in the patients were determined by the electrochemiluminescence method and cytokines were detected by flow cytometry. The relationship between serum 25(OH)D status and the severity of COVID-19, and the correlation between 25(OH)D levels and cytokines in COVID-19 patients were assessed.

RESULTS

Levels of 25(OH)D were significantly lower in the deceased group than in the other three groups (P < 0.05), and lower in the critical group than in the general group (P < 0.05). There were no significant differences in the 25(OH)D levels between the general and severe groups (P > 0.05). The levels of 25(OH)D (odds ratio = 0.986, 95% confidence interval: 0.973-0.998, P = 0.024) and IL-5 (odds ratio = 1.239, 95% confidence interval: 1.104-1.391, P = 0.04) were independent risk factors for the severity of COVID-19 disease upon admission. Serum 25(OH)D levels were able to predict the mortality of patients with COVID-19, and the predictive value was even higher when combined with IL-5 levels and eosinophil (Eos) count. Circulating 25(OH)D status correlated negatively with the expression of IL-5 (r=-0.262, P < 0.001) and was positively linked with CD8+ T cell counts (r=-0.121, P < 0.05) in patients with COVID-19.

CONCLUSIONS

This study found that the serum 25(OH)D status combined with IL-5 levels and Eos counts could be identified as a predictive factor for recognizing the risk of COVID-19 mortality. The serum 25(OH)D status in COVID-19 patients correlated negatively with the expression of IL-5. The potential mechanism for this relationship is worth further exploration.