Childhood asthma and vitamin D deficiency in Turkey: is there cause and effect relationship between them?

Abstract

BackgroundEpidemiological studies show that vitamin D deficiency and insufficiency are common worldwide and associated with many diseases including asthma. Our aim was to evaluate vitamin D insufficiency and its clinical consequences.MethodsThis cross-sectional study was carried out on 170 children consisted of 85 who were asthmatic and 85 who were not, aged 2 to 14 years in Tekirdag, Turkey, from September 2009 to May 2010. Children’s basal serum D vitamin levels were determined, and their eating habits, vitamin D intake, exposure to sunlight and use of health services during the previous year were investigated. The severity of asthma and levels of asthma control were assessed according to the Global Initiative for Asthma guidelines.ResultsThe difference between mean vitamin D levels in the asthmatic group (mean +/- SD) 16.6 +/- 8.5 ng/mL and the healthy control group (mean +/- SD) 28.2 +/- 19.5 ng/mL was found to be statistically significant (p < 0.001). Children in the asthma group had less exposure to sunlight and ate a diet less rich in vitamin D (p < 0.001). A significant difference was observed between the groups regarding the frequency of respiratory tract infections leading to emergency unit admissions and number of hospitalizations (p < 0.001). It was also shown that a decrease in vitamin D level increased the severity of asthma (p < 0.001) and decreased the frequency of controlled asthma (p = 0.010).ConclusionThis study has demonstrated the correlation between plasma 25 (OH) D levels and childhood asthma. Evidently, this relationship being influenced by multiple factors other than vitamin D, further studies should be conducted to explore the interrelation between all such factors.

Vitamin D Levels In Children with Bronchial Asthma

“…The mean duration of daily sunlight exposure between 10am and 3pm was 120.00± 5.11 minutes in children with asthma, which was significantly lesser than the 142.39±4.33 minutes in the healthy controls. This has been seen previously in a study done by Uysalol M et al, in Turkey [22]. The children with bronchial asthma having vitamin D deficiency(≤15ng/mL) in our study had a significantly lower FEV1% and FEV1/FVC% than bronchial asthma patients with insufficient vitamin D levels(>15ng/mL to <20ng/mL).…”

“…Vitamin-D deficiency has been linked to many disorders having an immunological basis like multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, Crohn's disease, type 2 diabetes mellitus and cardiovascular disease [15,17,22]. Vitamin-D has been proposed to have modulatory actions on the immune system.…”

Effects of Vitamin D Levels on Asthma Control and Severity in Children

“…Başvuruda hasta ve kontrol grubundaki çocukların yaş, cinsiyet, boy, kilo, anne baba ve kardeşlerde allerjik hastalık varlığı (astım, allerjik rinit ve atopik dermatit), güneş ışığı maruziyeti süresi (saat 10 ile 15 arasında en az 10 dakika) kaydedildi (22).…”

Bronchial Reactivity, Inflammatory and Allergic Parameters, and Vitamin D Levels in Children With Asthma

“…Additionally, asthma severity is related to socioeconomic status and parental educa- 40 In a recent systematic review of cohort studies concerning the association between low vitamin D levels and asthma in children, 3 cohort studies were eligible: 2 studies reported positive association, and the third found no association. 41 The high prevalence of vitamin D deficiency (36.6%) and insufficiency (46.5%) in our group of children with asthma is in agreement with previous studies.…”