Serum Vitamin D Levels and Markers of Severity of Childhood Asthma in Costa Rica

Abstract

Rationale: Maternal vitamin D intake during pregnancy has been inversely associated with asthma symptoms in early childhood. However, no study has examined the relationship between measured vitamin D levels and markers of asthma severity in childhood. Objectives: To determine the relationship between measured vitamin D levels and both markers of asthma severity and allergy in childhood. Methods: We examined the relation between 25-hydroxyvitamin D levels (the major circulating form of vitamin D) and markers of allergy and asthma severity in a cross-sectional study of 616 Costa Rican children between the ages of 6 and 14 years. Linear, logistic, and negative binomial regressions were used for the univariate and multivariate analyses. Measurements and Main Results: Of the 616 children with asthma, 175 (28%) had insufficient levels of vitamin D (,30 ng/ml). In multivariate linear regression models, vitamin D levels were significantly and inversely associated with total IgE and eosinophil count. In multivariate logistic regression models, a log 10 unit increase in vitamin D levels was associated with reduced odds of any hospitalization in the previous year (odds ratio [OR], 0.05; 95% confidence interval [CI], 0.004-0.71; P 5 0.03), any use of antiinflammatory medications in the previous year (OR, 0.18; 95% CI, 0.05-0.67; P 5 0.01), and increased airway responsiveness (a <8.58-mmol provocative dose of methacholine producing a 20% fall in baseline FEV 1 [OR, 0.15; 95% CI, 0.024-0.97; P 5 0.05]). Conclusions: Our results suggest that vitamin D insufficiency is relatively frequent in an equatorial population of children with asthma. In these children, lower vitamin D levels are associated with increased markers of allergy and asthma severity.For unclear reasons, the prevalence of allergic diseases and asthma increased from a period likely preceding the 1960s to the 1990s (1). Worldwide surveys have shown that asthma prevalence is highest in industrialized nations (2). Although there is a trend for increased prevalence of asthma in countries farthest from the equator, some nations near the equator have high asthma prevalence (e.g., Costa Rica) (2).Results of some, but not all, epidemiologic studies suggest that vitamin D deficiency is associated with an increased incidence of asthma symptoms (3-5). Our group has shown that higher maternal intakes of vitamin D during pregnancy are associated with decreased risks for recurrent wheeze in young children (6, 7), suggesting that vitamin D may play a role in the development of asthma. However, among those with established asthma, vitamin D may have a role in the manifestation of the disorder. Findings from in vitro studies (8) suggest that vitamin D may reverse steroid resistance in individuals with asthma, thus suggesting that vitamin D may play a role in the control of asthma. However, there has been no epidemiologic study of the relation between serum vitamin D levels and markers of asthma severity. The aim of the current analysis, therefore, was to examine the relationship ...

Serum 25-hydroxyvitamin D levels do not correlate with asthma severity in a case-controlled study of children and adolescents

“…The finding of a lack of relationship between vitamin D and asthma in our study is consistent with the report by Devereux et al (20) , but differed from the conclusions of other studies that showed a relationship between serum 25(OH)D concentrations and asthma symptom severity (12,13) . These association studies suggest that vitamin D could exert some beneficial effects in the treatment of steroid-resistant patients with asthma (3) .…”

“…In one large cohort study in asthmatic children in Costa Rica, Brehm et al (13) reported an inverse correlation between serum concentrations of 25-hydroxyvitamin D [25(OH)D] levels and markers of allergy and asthma severity. Another study from northern Italy showed a direct correlation between asthma control and serum 25(OH)D in a cohort of asthmatic children (14) .…”

Oral supplementation with 25(OH)D3 versus vitamin D3: Effects on 25(OH)D levels, lower extremity function, blood pressure, and markers of innate immunity

“…(51) Notably, low 25-hydroxyvitamin D levels were associated with elevated total immunoglobulin E (IgE) and eosinophil counts in a larger study of children with asthma. (52) Further, in patients with chronic kidney disease-associated inflammation, urinary MCP-1 protein and renal macrophage infiltration were significantly and inversely correlated with 1,25(OH)2D levels. (53) MCP-1 is considered a key modulator of monocyte activity and was suggested to be involved in the initiation and progression of atherosclerosis.…”

Enhanced production of IL-17A in patients with severe asthma is inhibited by 1α,25-dihydroxyvitamin D3 in a glucocorticoid-independent fashion

“…Several studies have pointed out striking links in populations between vitamin D deficiency and asthma severity or requirements for anti-inflammatory medication (27)(28)(29)(30). In previous studies investigating the immunological basis of this relationship, we have shown that 1 α,25-dihydroxyvitamin D3…”

“…This arises in part from studies demonstrating that patients with poorly controlled asthma and/or poor responsiveness to corticosteroid have significantly reduced vitamin D, at least as assessed by the circulating precursor 25-hydroxyvitamin D3 (27)(28)(29)(30)47). We and others have previously demonstrated an association with 25(OH)2D3 status and airways smooth muscle mass (27,28,48).…”