The Nutritional Significance of on Human Health: A GRADE-Assessed Systematic Review and Meta-Analysis of Clinical Trials.

This study aimed to assess the impact of supplementation (200-11,200 mg/day, 1-24 weeks) on health-related indices in populations including healthy, at-risk, and chronic disease individuals. A systematic review and meta-analysis were conducted using data from EMBASE, PubMed, Web of Science, and Scopus up to August 2024. Pooled analysis of 17 randomized controlled trials (RCTs) involving 971 participants revealed that supplementation demonstrated significant reductions in body mass index (BMI) (Weighted Mean Difference [WMD] = -0.43; 95% Confidence Interval [CI]: -0.77, -0.10;  = 0.011), creatinine (WMD = -0.14; 95% CI: -0.27, -0.02;  = 0.028), glutathione peroxidase (GPx) (WMD = 2.29; 95% CI: 1.67, 2.92;  < 0.001), and heart rate (HR) (WMD = -3.92; 95% CI: -7.45, -0.40;  = 0.029). No significant effects were observed on body fat, waist circumference, blood pressure, fasting glucose, lipid profile, inflammatory markers, or liver enzymes. Subgroup analyses indicated effects varied by health condition, dosage, duration, and age. Subgroup analyses revealed variations in the effects of supplementation based on health conditions, dosage, intervention duration, age at intervention, country, sample size, and publication year. Significant improvements were observed in BMI, TC, creatinine, and MDA in specific subgroups, such as those receiving lower doses (< 1400 mg/day) or those aged < 50 years. The GRADE profile for supplementation evaluated the certainty of the outcomes and indicated that the quality of evidence was very low across all outcomes. supplementation may have modest effects on certain health indices, but the evidence is limited by very low quality.