A Trial of Vitamin D and Health Advice for the Prevention of Upper Respiratory Tract Infections

McFlu2 COLD3 Prevention: A Randomized, Placebo-controlled, Double Blind Trial of Vitamin D and Health Advice for the Prevention of Upper Respiratory Tract Infections in McMaster University Students

The specific objectives of this investigation are to assess the effectiveness of daily gargling and vitamin D supplementation as preventative measures against incident upper respiratory tract infection (URTI) in students attending McMaster University. Investigators hypothesize that Vitamin D3 supplementation will decrease the incidence of symptomatic upper respiratory tract infections in university students Gargling will decrease the incidence of symptomatic upper respiratory tract infections in university students.

In the current study, we propose investigating the roles of vitamin D supplementation and of regular gargling to prevent URTI/ILI. Vitamin D may be an important factor in respiratory health. Observational studies have associated low serum 25(OH)D levels with more frequent and more severe respiratory infections. However, evidence is lacking that replacement of vitamin D decreases respiratory infections. Four interventional studies of vitamin D supplementation have noted a reduction in respiratory infections, with an estimated 5-25% reduction, but results were not statistically significant. In Japanese populations, gargling has been found to significantly reduce the incidence of upper respiratory tract infections by approximately 35% (Satomura et al., 2005). This intervention has not been studied in different populations but may be a useful personal practice to reduce URTI. We propose a 2X2 factorial, randomized, placebo-controlled trial of vitamin D/placebo and gargling/no gargling to study the effects of vitamin D supplementation and gargling on upper respiratory tract infections in McMaster students. This study will be conducted over two years, during September and October of each study year, to capture the natural peak in rhinovirus activity.

Participants will be given a weekly dose of 10,000 IU of vitamin D3 (oral capsule) and asked to gargle with tap water twice daily

Participants will be given a weekly dose of 10,000 IU of vitamin D3 (oral capsule) and will receive general health advice in place of gargling advice

Participants will be given an aesthetically matched placebo capsule to take once weekly and will be given general health advice in place of gargling advice.

Participants will be given an aesthetically matched placebo capsule to take once weekly and will be asked to gargle with tap water twice daily

Daily symptom surveys will be completed for 7 consecutive days follwing the onset of illness. A follow-up survey will be administered at day 14. Surveys will score the severity of symptoms.

Daily symptom surveys will be completed for 7 consecutive days follwing the onset of illness. A follow-up survey will be administered at day 14.

Inclusion Criteria: Current or part-time student at McMaster University 17 year of age or older Currently living: i. In residence or, ii. Off-campus with at least one student housemate Willing and able to sign an informed consent Exclusion Criteria: Students who do not meet the inclusion criteria Currently living at home with parents History or diagnosis of hypercalcemia Diagnosis of parathyroid disorder (hyper or hypo) Diagnosis of chronic kidney disease Use of anticonvulsants Malabsorption syndromes Diagnosis of sarcoidosis Currently pregnant or planning a pregnancy Inability to swallow capsules

Jefferson T, Del Mar CB, Dooley L, Ferroni E, Al-Ansary LA, Bawazeer GA, van Driel ML, Jones MA, Thorning S, Beller EM, Clark J, Hoffmann TC, Glasziou PP, Conly JM. Physical interventions to interrupt or reduce the spread of respiratory viruses. Cochrane Database Syst Rev. 2020 Nov 20;11(11):CD006207. doi: 10.1002/14651858.CD006207.pub5.

Goodall EC, Granados AC, Luinstra K, Pullenayegum E, Coleman BL, Loeb M, Smieja M. Vitamin D3 and gargling for the prevention of upper respiratory tract infections: a randomized controlled trial. BMC Infect Dis. 2014 May 19;14:273. doi: 10.1186/1471-2334-14-273.