Vitamin D for Viral Load Reduction
Vitamin D deficiency is common in chronic viral infection but correcting it does not lower viral load.
Overview
Verdict
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- 1000-2000 IU/day, more if deficient
- Expected timeframe
- 12 weeks
Protocol
- form
- Vitamin D3 (cholecalciferol); the CORONAVIT and COVIT-TRIAL studies used high-dose regimens
- duration
- Trials ran days to weeks in acute infection
- co factor
- Evidence is insufficient. Vitamin D induces cathelicidin and beta-defensin, which have antiviral activity in vitro, and observational studies during the pandemic associated low 25(OH)D with worse COVID-19 outcomes - though confounded by age, obesity, ethnicity and comorbidity. The randomised evidence is negative: a small Castillo trial suggested benefit but was methodologically criticised, while the larger CORONAVIT trial of 6,200 participants found no reduction in COVID-19 incidence or severity, and trials in hospitalised patients found no effect on viral clearance, length of stay or mortality.
- titration
- Not applicable for this indication; 4,000 IU/day is the tolerable upper intake level for routine use
- starting dose
- Not established. COVID-19 trials used regimens from 4,000 IU/day to 60,000 IU daily loading and single 200,000 IU doses
Evidence
What the studies say
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Martineau AR, Jolliffe DA, Hooper RL +3 more
Vitamin D reduced acute respiratory infection risk overall, with the largest benefit in deficient participants
Safety
Caveats
Supportive only. Discuss with the treating team.
Less likely to help if
Medical Disclaimer
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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.