Please select the eligibility criteria that correspond to the clinical trial below.
Title: 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
Brief Summary: 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

1. Vitamin D3 supplementation will decrease the incidence of symptomatic upper respiratory tract infections in university students
2. Gargling will decrease the incidence of symptomatic upper respiratory tract infections in university students.


Options:
A: Inclusion Criteria:

* The inclusion criteria are laboratory confirmed Covid-19 positive male or female subjects in the age range of 18-65 years, within seven days of the onset of mild to moderate symptoms of viral infection, already admitted in the hospital.

Exclusion Criteria:

* Edentulous patients, patients with low Glasgow coma score, intubated, immune-compromised, history of radiotherapy or chemotherapy will be excluded. Patients with known pre-existing chronic mucosal lesions such as lichen planus will also be excluded.
B: Inclusion criteria:

* Patients consider that they are in an early stage of common cold with symptoms of no more than 48 hours duration
* Symptom score of equal or more than 1 for for at least one of the symptoms sore throat, runny nose and blocked nose on a 0-3 verbal rating scale
* Total symptom score of equal or less 9 for symptoms headache, muscle ache, chilliness, sore throat, blocked nose, runny nose, cough, and sneezing measured on a 0-3 verbal rating scale
* Patients agree to refrain from taking any products intended to prevent, intervene in, or treat cough/colds/flu, starting at study entry and continuing through day 10 (e.g. those containing zinc, Echinacea); use of a daily multivitamin is allowed.

Exclusion criteria:

* Known hypersensitivity or are allergic to any component of the test device
* Clinically significant cardiovascular, endocrinological, neurological, respiratory, gastrointestinal disease or history or any current disease that is considered by the investigator as a reason for exclusion e.g. current allergic rhinitis, chronic obstructive pulmonary disease
* Severe nasal septum deviation or other condition that could cause nasal obstruction such as the presence of nasal polyps.
* History of nasal or sinus surgery that in the opinion of the investigator may influence symptom scores
* Taking any prescribed medication other than for contraception, that is considered by the investigator as a reason for exclusion e.g. systemic steroids, intranasal medicines, antibiotics
* Common cold or flu like symptoms for more than 48 hours.
* Recent (within the previous 2 days) intake of a common cold medicine that in the opinion of the investigator may influence symptom scores (analgesics, nasal decongestants, cough medicines)
* Current smoker (more than 10 cigarettes a day)
C: Inclusion Criteria:

* Clinical diagnosis of Covid-19 infection by the patient's general practitioner and hospital doctor
* Clinical signs started less than 8 days ago.
* Virological confirmation
* Understanding and acceptance of the trial.
* Written agreement to participate in the trial

Exclusion Criteria:

* Pregnancy
* Breastfeeding
* Inability to comply with protocol
* Lack of written agreement
D: 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

Answer: D