1.
Excessive Vitamin A Supplementation Increased the Incidence of Acute Respiratory Tract Infections: A Systematic Review and Meta-Analysis.
Zhang, Y, Lu, Y, Wang, S, Yang, L, Xia, H, Sun, G
Nutrients. 2021;(12)
Abstract
(1) Background: vitamin A deficiency (VAD) is highly prevalent in children living in poor conditions. It has been suggested that vitamin A supplementation (VAS) may reduce the risk of acute respiratory tract infections (ARTI). Our study provides updates on the effects of oral VAS (alone) in children on ARTI and further explores the effect on interesting subgroups. (2) Methods: eight databases were systematically searched from their inception until 5 July 2021. The assessments of inclusion criteria, extraction of data, and data synthesis were carried out independently by two reviewers. (3) Results: a total of 26 randomized trials involving 50,944 participants fulfilled the inclusion criteria. There was no significant association of VAS with the incidence of ARTI compared with the placebo (RR 1.03, 95% CI 0.92 to 1.15). Subgroup analyses showed that VAS higher than WHO recommendations increased the incidence of ARTI by 13% (RR 1.13, 95% CI 1.07 to 1.20), and in the high-dose intervention group, the incidence rate among well-nourished children rose by 66% (RR 1.66, 95% CI 1.30 to 2.11). (4) Conclusions: no more beneficial effects were seen with VAS in children in the prevention or recovery of acute respiratory infections. Excessive VAS may increase the incidence of ARTI in children with normal nutritional status.
2.
Association of Vitamin D or Calcium Supplementation with Cardiovascular Outcomes and Mortality: A Meta-Analysis with Trial Sequential Analysis.
Zhang, Y, Li, Y, Liu, J, Wei, X, Tan, N, Zhang, J, Wang, W, Wang, Y
The journal of nutrition, health & aging. 2021;(2):263-270
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Abstract
BACKGROUND To exploring the role of vitamin D or calcium supplementation in reducing all-cause mortality and cardiovascular outcomes. METHODS The search was restricted to systematic reviews or meta-analyses published from January 1, 2010, to July 7, 2019. An additional search was performed to identify recently published randomized controlled trials (from January 1, 2015, to July 7, 2019). Homogeneous results from different studies were pooled using Revman 5.3 software. RESULTS Twenty-three studies involving 89,251 participants were ultimately included in this meta-analysis. No associations were observed between the supplementation and composite cardiovascular outcomes, consisting of all-cause mortality, cardiovascular mortality, myocardial infarction, and other MACEs. CONCLUSIONS Whether used alone or in combination, vitamin D and calcium supplementation do not exert meaningful effects on all-cause mortality, cardiovascular mortality, MACEs or MI among community-dwelling adults.
3.
Possible anti-obesity effects of phytosterols and phytostanols supplementation in humans: A systematic review and dose-response meta-analysis of randomized controlled trials.
Ghaedi, E, Varkaneh, HK, Rahmani, J, Mousavi, SM, Mohammadi, H, Fatahi, S, Pantovic, A, Darooghegi Mofrad, M, Zhang, Y
Phytotherapy research : PTR. 2019;(5):1246-1257
Abstract
Present meta-analysis investigates the effects of phytosterols and phytostanol (PS) supplementation on anthropometric indices, using data from randomized controlled trials. We performed a systematic search in the databases: PubMed, Scopus, Cochran, and Web of Science. Weighted mean difference (WMD) with 95% confidence intervals (CIs) were presented. Overall, 79 randomized controlled trials investigated the effects of PS on anthropometric indices. Meta-analysis results did not reveal any significant effect of PS supplementation on weight (66 trials-WMD: -0.083 kg; CI [-0.233, 0.066]; I2 = 42.5%), percentage fat mass (6 trials-WMD: -0.090%; CI [-0.789, 0.610]; I2 = 0.0%), and waist circumference (WC; 5 trials-WMD: -0.039 cm; CI [-0.452, 0.374]; I2 = 0.0%). However, body mass index (BMI) significantly decreased after PS supplementation (39 trials-WMD: -0.063 kg/m2, p = 0.024, I2 = 25.1%). Subgroup analyses showed that PS supplementation in subjects with baseline BMI ≥25 and hyperlipidemic significantly decreased body weight and BMI. The overall results showed that although PS supplementation did not affect anthropometric indices (except BMI), baseline status regarding BMI and hyperlipidemia and also dose and duration could be contributing factors for favorable effects.