Table 2. Estimated effects of selected nutritional interventions on ALRI incidence, morbidity or mortality.
| Nutritional intervention | ALRI outcome | Effect sizea | Source | Comments |
|---|---|---|---|---|
| Vitamin A supplementation | Incidence | 0.95 (0.89–1.01) | Meta-analysis of five trials23 | Recent systematic review confirmed the null effects on incidence and mortality24 |
| Mortality | 0.98 (0.75–1.28) | Meta-analysis of five trials23 | ||
| Zinc supplementation | Incidence | 0.80 (0.70–0.92) | Meta-analysis of four trials44 | Included trials of supplementation for at least 3 months |
| Mortality | 0.85 (0.65–1.11) | Unpublished meta-analysis of three trials3 | Effect size (95% CI) in individual trials: Bangladesh – cannot calculate relative rate [10 deaths in placebo group (n = 812) and 0 in zinc arm (n = 809)]; Nepal 0.90 (0.64–1.26); United Republic of Tanzania 0.88 (0.5–1.5) | |
| Breastfeeding promotion | Hospitalization | 0.85 (0.57–1.27) | Single large trial in Belarus16 | Outcome ascertained by maternal recall |
| Iron supplementation | Incidence | 0.97 (0.83–1.23) | Meta-analysis of eight trials31 | Trials published since the meta-analysis have confirmed the null effect32 |
| Iron and folic acid supplementation | Incidence | 0.92 (0.7–1.09) | Single large trial in Nepal34 | In a companion trial conducted in a malaria-endemic region (Pemba), iron-folic acid (with or without zinc) significantly increased the risk of death due to non-malarial infections (HR 1.61, 95% CI: 1.03–2.52), although the specific effect on ALRI mortality was not estimated58 |
| Mortality | 0·88 (0.50–1.46) | Single large trial in Nepal34 | ||
| Iron, folic acid and zinc supplementation | Incidence | 0.91 (0.76–1.08) | Single large trial in Nepal34 | |
| Mortality | 0.80 (0.45–1.34) | Single large trial in Nepal34 | ||
| Multiple micronutrient-fortified milk | Incidence | 0.74 (0.57–0.97) | Single trial in India60 | Experimental milk contained higher concentrations of vitamins A, E, C, iron, zinc, selenium and copper than the control milk |
ALRI, acute lower respiratory infection; CI, confidence interval; HR, hazard ratio. a Relative risk or relative rate, odds ratio or hazard ratio, compared with placebo. Values in parentheses are 95% CI.