The effect of zinc supplementation on anthropometric measurements in healthy children over two years: a systematic review and meta-analysis.

BACKGROUND: Zinc deficiency is one of the most important micronutrient deficiencies in children that can affect the children's growth pattern. In this regard, different studies were conducted to assess the effect of zinc supplementation on growth patterns in healthy children. To the best of our knowledge, no systematic review has summarized the results of these studies. So, in the present study, we systematically reviewed the result of the studies that assessed the effect of zinc supplementation on anthropometric parameters in healthy, over 2-year-old children. METHODS: A systematic search was carried out in PubMed, Scopus, and Web of Science from inception to November 2021. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). RESULTS: The pooled results of eight studies, including 1586 participants, showed that zinc supplementation significantly increases height [(WMD): 0.9, 95% CI: (0.27, 1.52), p < 0.001], weight [(WMD): 0.51, 95% CI: (0.06, 0.97), p < 0.001], height for age (HAZ) [(WMD): 0.07, 95% CI: (0.03, 0.10), p < 0.001]. Also, meta-regression analysis did not reveal any significant association between dose and duration of intervention and anthropometric parameters. CONCLUSION: The present study demonstrates the beneficial effects of zinc supplementation on weight, height, and HAZ.

Administration of dietary antioxidants for patients with inflammatory bowel disease: A systematic review and meta-analysis of randomized controlled clinical trials.

OBJECTIVE: Accumulating evidence has been reported regarding the effect of dietary antioxidants on clinical variables in IBD patients, however, findings are controversial. This systematic review and meta-analysis aimed to investigate effect of dietary antioxidants on clinical variables in patients with IBD or its subtypes. METHODS: We searched PubMed, Scopus, and ISI Web of Science from inception to January 2021 using relevant keywords. Data were pooled by using the random-effect model. All statistical analyses were done using STATA version 14. RESULTS: Our meta-analysis was exclusively done on studies about the effect of curcumin on IBD patients, because limited studies were done on other antioxidants. Curcumin administration resulted in significant increment of clinical remission in patients with IBD (SMD: 0.86%, 95% CI: 0.16, 1.56, p = 0.016), significant remission in clinical symptoms (SMD: -0.96 score, 95% CI: -1.34, -0.57, p < 0.001), and significant increment in endoscopic remission in IBD patients (SMD: 0.51%, 95% CI: 0.16, 0.85, p = 0.004), comparing to control group. Curcumin supplementation also made better clinical response than control group (SMD: 0.74%, 95% CI: 0.22, 1.26, p = 0.005) and also resulted in significant improvement in quality of life of patients with IBD, as compared to control group (SMD: 1.23 score, 95% CI: 0.72, 1.74, p < 0.001). CONCLUSIONS: Our meta-analysis showed that curcumin significantly improved clinical and endoscopic remissions in IBD patients. This supplementation also caused significant reduction in clinical symptoms of IBD patients along with better clinical response and the increased quality of life. Further researches with larger sample size and longer period of intervention are required to evaluate efficacy of dietary antioxidants on clinical variables in patients with IBD.