Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of aggregate data from randomised controlled trials

This review (42 RCTs; n=46,331) found vitamin D supplementation reduced risk of acute respiratory infections (OR 0.91; 95% CI 0.84-0.99; but significant heterogeneity); protection was noted with doses of 400-1000IU daily for up to 12 months. Relevance to Covid-19 is unknown.

SPS commentary:

This systematic review, which has not yet been peer reviewed, was considered by NICE, Public Health England and the Scientific Advisory Committee on Nutrition when reviewing the evidence to inform a NICE rapid guideline on vitamin D and Covid-19, but a number of limitations of the included studies was noted. The NICE guideline encourages people to follow UK government advice on taking a vitamin D supplement to maintain bone and muscle health but does not recommend that a supplement be offered solely to prevent or treat COVID‑19, except as part of a clinical trial.

MedRxiv

Resource links:

NICE rapid guideline on vitamin D and Covid-19