Vitamin D in Pediatric Asthma: a Randomized Controlled Open-label Pilot Trial

Overview

This is a pilot randomized controlled trial of lower vs. higher dose vitamin D supplementation in D-deficient asthmatic children, to determine necessary sample sizes for outcome measures in a larger multisite study, and to examine possible relationships and effect sizes between various biological markers that may be important to the pathophysiology of childhood asthma. Aims of the study are to: 1. Evaluate effect sizes for relationships between serum 25OH-vitD and omega-fatty acid (FA) biomarkers, before and after supplementation with lower or higher dose vitamin D, on immune function, and asthma severity. 2. Characterize changes in innate and adaptive immune function and inflammatory responses in asthmatic D-deficient youth at baseline and after vitD supplements, by dietary O6:O3FA status and vitD dose.

An estimated up to 120 youth meeting eligibility criteria will be screened for vitamin D deficiency, and if found deficient, will be offered enrollment in this study. Eligible children who assent and whose parent/guardian consent to participate will be randomized to low dose vs. higher dose vitamin D to take across a 3-month period of time. Blood, questionnaires, and pulmonary function tests will be obtained at baseline and end of study. Weekly phone calls will check on any questions or concerns the participant or their family may have. Aims and Hypotheses: Aim I: Evaluate effect sizes for relationships between omega-FA and vitD biomarkers, pre- and post- low and higher dose vitamin D supplementation, in diet, immune function, and asthma severity. Aim II: Characterize changes in innate and adaptive immune function and inflammatory responses in asthmatic D-deficient youth at baseline and after vitD supplements, by O6:O3FA status and vitD dose. Exploratory: Compute effect sizes/odds ratios for differences in pulmonary function, self-reported asthma severity, depressive symptoms, hospitalization/ED visits, and medication changes based on treatment group. Effect sizes will be calculated for all continuous outcome variables by: Effect Size (ES) = Average of the post-test scores - Average of the pre-test scores Average standard deviation Odds ratios for the categorical asthma severity variable will be computed through logistic regression by treatment group with no covariates. Examine differences in pulmonary function tests, self-reported asthma severity, depressive symptoms, hospitalization/ED visits, and medication changes based on treatment group. Omega fatty acid intake and allergic status will be included as potentially mediating variables.