Vitamin D Supplementation Lowers Risk for Acute Respiratory Tract Infections

摘要

Participants with severe vitamin D deficiency benefitted most. Observational evidence suggests that low blood concentrations of 25-hydroxyvitamin D are associated with susceptibility for acute respiratory tract infections. In this meta-analysis of 25 randomized, double-blind, placebo-controlled trials, researchers used individual participant data on about 11,000 children and adults to examine whether vitamin D supplementation lowered risk for acute respiratory tract infections (upper, lower, and unclassified location). In all studies, vitamin D was administered orally: bolus doses every 1 to 3 months, weekly doses, daily doses, or a combination of bolus and daily doses. Vitamin D supplementation significantly lowered risk for acute respiratory tract infections (by 12%; adjusted odds ratio, 0.88). This protective effect was observed only in participants who received daily or weekly vitamin D and was stronger in participants whose baseline 25-hydroxyvitamin D levels were < 10 ng/mL (<25 nmol/L; adjusted OR, 0.3) than in those whose baseline levels were higher (AOR, 0.75). In addition, the protective effect appeared to be limited to upper respiratory infections. Vitamin D supplementation was not associated with serious adverse events.