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

Frontiers in Immunology
Q1
Oct 2022
Citations:32
Influential Citations:3
Systematic Reviews / Meta-Analyses
90
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Enhanced Details

Methods
Eight randomized controlled trials (657 participants) in adults with PCR-confirmed SARS-CoV-2 infection; settings included inpatients and some outpatients; study designs included double-blind and open-label randomized trials conducted across several countries.
Intervention
Regimens varied: calcifediol with an initial 532 µg dose followed by 266 µg on days 3, 7, 14, 21 and 28; calcitriol 0.5 µg daily for 14 days; cholecalciferol regimens included daily high-dose doses (e.g., 1500 µg for 7–14 days; 125 µg daily for 14 days; 250 µg daily for 14 days) or a single 5,000 µg bolus; administration was after COVID-19 diagnosis to inpatients and some outpatients; follow-up varied by trial.
Results
Vitamin D supplementation did not significantly reduce mortality or most clinical outcomes in COVID-19, though a trend toward lower mortality was observed, particularly with repeated dosing. Length of hospitalization tended to be slightly shorter; effects on ICU admission and mechanical ventilation were not statistically significant. Authors conclude that repeated vitamin D dosing after COVID-19 diagnosis could help reach sufficient serum vitamin D and may improve immune response, but overall evidence is of low quality and further robust randomized trials are needed.
Limitations
Small number of trials and events; heterogeneity of dosing regimens, populations, and follow-up; some studies open-label; potential risk of bias; overall certainty low to moderate.

Abstract

Vitamin D supplementation and its impact on immunoregulation are widely investigated. We aimed to assess the prevention and treatment efficiency of vitamin D supplementation in the context of coronavirus disease 2019 (COVID-19) and any disease-relate...