Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Abstract

Objectives To assess the overall effect of vitamin D supplementation on risk of acute respiratory tract infection, and to identify factors modifying this effect.Design Systematic review and meta-analysis of individual participant data (IPD) from randomised controlled trials.Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and the International Standard Randomised Controlled Trials Number registry from inception to December 2015.Eligibility criteria for study selection Randomised, double blind, placebo controlled trials of supplementation with vitamin D3 or vitamin D2 of any duration were eligible for inclusion if they had been approved by a research ethics committee and if data on incidence of acute respiratory tract infection were collected prospectively and prespecified as an efficacy outcome.Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. IPD were obtained for 10 933 (96.6%) participants. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001). In subgroup analysis, protective effects were seen in those receiving daily or weekly vitamin D without additional bolus doses (adjusted odds ratio 0.81, 0.72 to 0.91) but not in those receiving one or more bolus doses (adjusted odds ratio 0.97, 0.86 to 1.10; P for interaction=0.05). Among those receiving daily or weekly vitamin D, protective effects were stronger in those with baseline 25-hydroxyvitamin D levels <25 nmol/L (adjusted odds ratio 0.30, 0.17 to 0.53) than in those with baseline 25-hydroxyvitamin D levels ≥25 nmol/L (adjusted odds ratio 0.75, 0.60 to 0.95; P for interaction=0.006). Vitamin D did not influence the proportion of participants experiencing at least one serious adverse event (adjusted odds ratio 0.98, 0.80 to 1.20, P=0.83). The body of evidence contributing to these analyses was assessed as being of high quality.Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.Systematic review registration PROSPERO CRD42014013953.

Vitamin D deficiency is an independent predictor of mortality in patients with chronic heart failure

“…The Vitamin D Assessment study (ViDA) in 5100 healthy subjects, aged > 50 years, recently reported that 100,000 IU oral vitamin D 3 monthly was neutral for the prevention of CV disease [49,50], with a low rate of 25[OH]D deficiency in participants (25%), a lower than expected endpoint rate and monthly doses cited as possible reasons [51]. Metaanalysis and data from ViDA and other studies describe that benefits on clinical outcomes are greatest in the most deficient, and in studies using daily dosing regimens (as in VINDICATE) rather than monthly [52][53][54][55].…”

Risks of the ‘Sunshine pill’ – a case of hypervitaminosis D

“…The reported non-musculoskeletal health benefits of vitamin D supplementation, 6,7 including links to sepsis severity, 8 acute respiratory distress syndrome (ARDS) 9 and respiratory tract infections (RTIs) 10 have seen its use increase significantly. There are also widespread claims in non-medical publications and the media that vitamin D supplementation is a 'miracle cure'.…”

Non-classical effects of vitamin D

“…Имеются данные, поддержи-вающие возможную роль дефицита витамина D в раз-витии туберкулеза у детей, рецидивирующего острого среднего отита и тяжелого бронхиолита, тогда как связь с рецидивирующим фаринго-тонзиллитом, острым ри-носинуситом и внебольничной пневмонией требует под-тверждения [33]. Мета-анализы проведенных РКИ указы-вают на снижение заболеваемости туберкулезом и ОРВИ при приеме препаратов витамина D среди взрослых, особенно при ежедневных режимах приема и среди лиц с низкими уровнями 25(OH)D [34,35].…”