Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis

Abstract

Acute respiratory tract infections (ARIs) are a leading cause of ill-health and death globally. Individual or multiple micronutrients have been shown to modulate immune function and affect the risk and severity of a number of infectious diseases. We systematically reviewed the evidence on the impact of micronutrient supplements to reduce the occurrence of ARIs and shorten the duration of ARI symptoms among adults. Random effects meta-analyses were conducted to estimate the pooled effects of vitamin D, vitamin C, zinc and multiple micronutrient supplementation (MMS) on the occurrence of ARIs and the duration of ARI symptoms. Vitamin D supplementation reduced the risk of ARI (risk ratio (RR)=0.97; 95% CI 0.94 to 1.00; p=0.028) and shortened the duration of symptoms (per cent difference: −6% (95% CI −9% to −2%; p=0.003)). The RR of vitamin D to prevent ARI was farther from the null when diagnosis was based on clinical diagnosis or laboratory testing, compared with self-report and when the loading dose was <60 000 IU. Vitamin C supplementation reduced the risk of ARIs (RR=0.96; 95% CI 0.93 to 0.99; p=0.01) and shortened the duration of symptoms (per cent difference: −9% (95% CI −16% to −2%; p=0.014)). The effect of vitamin C on preventing ARI was stronger among men and in middle-income countries, compared with women and high-income countries, respectively. Zinc supplementation did not reduce the risk of ARIs but shortened the duration of symptoms substantially (per cent difference: −47% (95% CI −73% to −21%; p=0.0004)). Our synthesis of global evidence from randomised controlled trials indicates that micronutrient supplements including zinc, vitamins C and D, and multiple micronutrient supplements may be modestly effective in preventing ARIs and improving their clinical course. Further research is warranted to better understand the effectiveness that individual or multiple micronutrients have on SARS-CoV-2 infection and treatment outcomes.

Association of serum vitamin D levels with disease severity, systemic inflammation, prior lung function loss and exacerbations in a cohort of patients with chronic obstructive pulmonary disease (COPD)

“…The frequency of exacerbations is an important factor in COPD severity that strongly affects patients (29,37,38). Clinically, associations between vitamin D deficiencies and respiratory infections have been proposed for the general population as well as in COPD (7,9,12,39). We did not observe an association between 25-OHD levels and the exacerbation frequency in our cohort.…”

“…In COPD, vitamin D deficiency has been shown to correlate with airway obstruction and the frequency of exacerbations due to respiratory infections, which display a major complication and cause for disease progression (8)(9)(10)(11). This is in line with the observation that vitamin D deficiency is associated with an increased risk of respiratory infections in the general population and that vitamin D supplementation can have beneficial effects on acute respiratory infection (9,12). However, while also in meta-analyses lower vitamin D levels have been found associated with exacerbations, vitamin D deficiency not necessarily increases the risk for exacerbations (13).…”

Vitamin C for sepsis intervention: from redox biochemistry to clinical medicine

“…While it is imperative to develop an optimal regimen for using vitamin C to treat septic patients, efforts should also be devoted to determining if vitamin C-based strategies could also be employed for preventive purpose in high-risk patients, such as those with advanced age, dietary insufficiency, comprised immunity, or other concomitant morbidities. In this regard, a recent systemic review and meta-analysis suggested that vitamin C supplement in normal individuals could reduce the risk of respiratory tract infections, including influenza [98].…”

A digital dietary assessment tool may help identify malnutrition and nutritional deficiencies in hospitalized patients

“…In a fee-for-service health care delivery model, it is a reimbursable diagnosis, coded as either a complication or comorbidity (CC) or major complication or comorbidity (MCC) which increase the relative weighting factor for diagnosis related groups (DRGs) (Doley and Phillips 2019). Identifying and addressing malnutrition also supports providers and health systems working within value-based care contracts (Arensberg et al 2020). Nutrition interventions that address malnutrition may reduce the length of hospital stay, cost of care, and mortality (Beck et al 2013, Milne et al 2009, Somanchi et al 2011).…”