COVID-19 pandemic prevented start-up

A phase II randomised, placebo-controlled trial to identify the optimal regimen of vitamin D supplementation for rhinovirus protection, determined by host responses to a clinically induced rhinovirus challenge. The primary outcome is rhinovirus titre after inoculation with rhinovirus; secondary outcomes are self-reported respiratory symptom scores, concentrations of cytokines and chemokines sampled from the nasal mucosa, and the transcriptional responses of nasal epithelial cells.

Inclusion Criteria:

1. Age 18-70 years
2. Gives written informed consent
3. Serum 25-hydroxyvitamin D concentration <75 nmol/L
4. Agrees not to take supplement containing vitamin D during participation
5. Agrees not to commence smoking or vaping during participation

Exclusion criteria:

1. Current smoker or vaper

2. Taken vitamin D supplement or other supplement containing vitamin D, in previous 3 months

3. Sunny holiday abroadI, defined as any location 51 degrees North/South of the equator, for ≥1 week, in the previous 3 months

4. Dependent(s) <6 months old

5. Positive serology for anti-RV16 antibodies

6. Living with someone with severe airways disease

7. Any of the following medical conditions:

   1. Diabetes mellitus
   2. Asthma
   3. Chronic Obstructive Pulmonary Disease
   4. Respiratory allergies
   5. Sarcoidosis
   6. Hyperparathyroidism
   7. Nephrolithiasis
   8. Active tuberculosis
   9. Liver failure
   10. Renal failure
   11. Lymphoma or other malignancy not in remission for ≥ 3 years

De-identified IPD will be shared with other researchers subject to terms of Data Transfer Agreement and IRB approval

2 years after completion of the trial