Vitamin D supplementation for the treatment of COVID-19: A systematic review and meta-analysis of randomized controlled trials

Study answer

What this study found

Vitamin D supplementation did not show a statistically significant overall benefit for mortality or other key clinical outcomes in adults with COVID-19. The review noted a non-significant trend toward lower mortality, with the most favorable signal seen for repeated dosing after diagnosis. Across studies, the evidence was low to moderate quality and heterogeneous, so firm conclusions about clinical benefit or optimal dosing could not be made.

Study & population

Systematic review and meta-analysis of 8 randomized controlled trials including 657 adults with confirmed COVID-19.

Intervention

Vitamin D was evaluated in multiple forms across 8 randomized controlled trials: calcifediol, calcitriol, and cholecalciferol.

Key limitation

The evidence base was small and heterogeneous, with different vitamin D forms, doses, timing, and patient settings across only 8 trials.

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Original abstract