Dietary Supplements for COVID-19

Dietary Supplements to Reduce Symptom Severity and Duration in People With SARS-CoV-2: A Randomized, Double Blind, Placebo Controlled Clinical Trial

This is a double blind, placebo controlled, phase III randomized controlled trial evaluating the effects of the dietary supplements vitamin C, vitamin D, vitamin K, and zinc versus placebo on the overall health, symptom severity, and symptom duration of outpatients diagnosed with SARS-CoV-2.

This study proposed is a double-blind, placebo-controlled, phase III randomized controlled trial powered to detect meaningful differences in the overall health and symptom severity of people with COVID-19 between the treatment and control arms. Eligible participants will be randomly assigned, using a web randomization system, in a ratio of 1:1 to one of the following groups: (1) nutrient therapy with vitamin D, vitamin C, vitamin K2, and zinc or (2) placebo. Total trial duration will be 12 weeks. Nutrients or placebo will be given for a period of 21 days following enrolment and randomization. Total trial duration will be 12 weeks. Adverse events will be collected during the treatment phase plus one additional week (maximum 4 weeks).

With respect to the primary outcome of participant-reported overall health, power calculations were conducted based on between-group differences at a single time point (21 days) and Cohen's guideline for a small effect size of 0.3. A sample size of 176 (88 per arm) provides 80% power to detect a difference at an α of 0.05. To account for an approximate 10-15% lost to follow-up we will enrol 200 participants (100 per arm).

Inclusion Criteria:

1. Adults (≥18) who test positive for SARS-CoV-2 in an outpatient setting
2. Access to internet

Exclusion Criteria:

1. Symptom onset greater than 4 days prior to enrolment
2. Supplementing regularly with >500 mg vitamin C, >1000 units vitamin D, >120 mcg vitamin K (any form), or >15 mg zinc taken daily within the past month
3. Currently taking warfarin or an equivalent vitamin K antagonist anticoagulant
4. End stage chronic kidney disease
5. History of calcium oxalate kidney stones
6. Active granulomatosis (sarcoidosis, tuberculosis, lymphoma)
7. Known hypercalcemia or hypervitaminosis D
8. Currently taking either of the following antibiotics: cephalexin, tetracyclines
9. Participating in an investigational study or participation in an investigational study within the past 30 days
10. Any reason which, under the discretion of the qualified investigator or delegate, would preclude the patient from participating.