70 High Dose Vitamin D for the Prevention of Wheezing in Preschoolers: A Secondary Analysis of a Randomized Clinical Trial
Bibliographic record
Abstract
Wheeze is a common condition affecting nearly one in three preschool children with few effective preventive interventions. Observational studies have suggested that vitamin D may improve lung function in children and adults, though no trial has examined whether a high dose of vitamin D supplementation can prevent wheezing in healthy preschool children. This study aimed to determine whether high dose vitamin D supplementation could reduce wheezing in young healthy children compared to a standard dose of vitamin D supplementation. This study was a prespecified secondary analysis of a 1:1 parallel, multicenter, superiority randomized clinical trial. The trial was conducted through a large primary care research network in Toronto, ON. Children with health conditions affecting growth, chronic condition(s) except for asthma, severe developmental delays, and children with gestational age < 32 weeks were excluded. Healthy children age 1 to 5 years were randomized to either ‘standard-dose’ (400IU/day) or ‘high-dose’ (2000IU/day) orally supplemented vitamin D. Parents administered 1 drop/day of the assigned formulation (Kids Ddrops containing vitamin D3) to their child between time of enrolment (September-November) until follow-up (April-June). The outcome for this prespecified secondary analysis was one or more wheezing episode ascertained monthly by telephone. A binomial regression model was used to obtain the relative risk of one or more wheezing episodes in the high-dose group compared to the standard-dose group with 95% confidence intervals. Between September 2011 and June 2015, 703 children were recruited of which 631 (89.6%) provided data on wheezing. Mean age was 2.03 years and 57% were male. At baseline, 17 % of children in the high-dose group and 15 % of children in the standard-dose group had serum 25-hydroxyvitamin D levels below 75 nmol/L. Wheezing in the past was reported at baseline by 22% in the high-dose group and 20% in the standard-dose group. One or more wheezing episodes occurred in 16% of participants in the high-dose group and 12% of participants in the standard-dose group over the winter season which was not statistically different (RR=1.38, 95% CI: 0.93, 2.07, p=0.12). In this randomized clinical trial of healthy young children, the risk of wheezing was not reduced by high-dose vitamin D compared to standard-dose supplementation. These results are consistent with several observational studies of vitamin D supplementation and wheeze in childhood. The trial was conducted across multiple sites, enhancing the generalizability of results. This study was limited by parent-reported outcomes, though gold standard tests for wheeze (e.g. spirometry) are challenging to perform in young children.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.023 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.003 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".