25-hydroxyvitamin-d-2 and Asthma

Biochemical markers of bone turnover were studied in prepubertal school children with asthma in two randomized double-blind crossover trials with run-in, treatment, and wash-out periods of 2 weeks. One group (n = 11) was treated with 2.5 and 5.0 mg prednisolone, the other (n = 14) with 200 and 800 micrograms inhaled budesonide per day. Serum osteocalcin, serum total alkaline phosphatase, fasting urinary excretion of hydroxyproline and calcium, serum 25-hydroxyvitamin D, and 1,25 dihydroxyvitamin D were assessed. A dose-related reduction of serum osteocalcin (Page's test for trend: P = 0.04; z = -2.3) and of the fasting urinary hydroxyproline:creatinine ratio (Page's test for trend: P = 0.05; z = -2.0) was found in the children who were treated with prednisolone. Inhaled budesonide was not associated with statistically significant effects on any of the biochemical markers. Short-term treatment with low daily doses of prednisolone may cause a suppression of bone turnover in children with asthma. To reduce the risk of adverse effects on bone turnover, doses of inhaled budesonide up to 800 micrograms daily may be preferable to low doses of prednisolone. Bone turnover remains to be evaluated during long-term treatment.

Topics: 25-Hydroxyvitamin D 2; Administration, Inhalation; Administration, Oral; Adolescent; Alkaline Phosphatase; Asthma; Biomarkers; Bone Development; Bone Resorption; Bronchodilator Agents; Budesonide; Calcifediol; Calcitriol; Calcium; Child; Creatinine; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Hydroxyproline; Male; Osteocalcin; Prednisolone; Pregnenediones

Higher serum total 25-hydroxyvitamin D (25(OH)D) concentrations have been associated with better lung function and lower risk of allergic disease. 25(OH)D3 constitutes the majority of total 25(OH)D and has been suggested to be more potent than 25(OH)D2. We studied the prospective associations of 25(OH)D2 and 25(OH)D3 with asthma, wheezing, flexural dermatitis, and lung function in children who participated in the Avon Longitudinal Study of Parents and Children-a population-based contemporary birth cohort of children born in 1991-1992 from South West England.. Serum 25(OH)D2 and 25(OH)D3 concentrations, measured at a mean age of 9.8 years, were related to incident cases of wheezing (study sample: n = 3,323, 141 cases; 4%), asthma (n = 3,323, 464 cases; 14%), and flexural dermatitis (n = 3,748, 300 cases; 8%), as well as lung function (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and mid-forced expiratory flow assessed at a mean age of 15.5 years: n = 2,259).. 25(OH)D2 was inversely associated with flexural dermatitis (adjusted odds ratio per doubling of exposure = 0.83 [95% confidence interval = 0.72-0.94]) and wheezing (0.83 [0.68-1.00]), and 25(OH)D3 was positively associated with flexural dermatitis (1.09 [1.00-1.18]) and wheezing (1.14 [1.03-1.28]). 25(OH)D2 was weakly positively associated with FEV1, and FVC. 25(OH)D3 was not associated with lung function.. These results suggest that higher 25(OH)D3 concentrations are associated with increased risk of wheezing and flexural dermatitis. Despite being one of the few prospective studies and being able to adjust for confounders, these findings need replication. Our results do not provide strong evidence that lower concentrations of vitamin D are detrimental to respiratory and allergic health in children.

Topics: 25-Hydroxyvitamin D 2; Adolescent; Asthma; Calcifediol; Child; Cohort Studies; Dermatitis; England; Female; Humans; Incidence; Longitudinal Studies; Male; Prospective Studies; Regression Analysis; Respiratory Function Tests; Respiratory Sounds; Vitamin D Deficiency