Dietary Supplement Interventions and Sleep Quality Improvement: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of 28 randomized controlled trials
PubMed 41470897 · doi:10.3390/nu17243952
What was done
Authors conducted a systematic review and meta-analysis searching PubMed, Web of Science, CNKI, ScienceDirect, Wiley, and CVIP databases for randomized controlled trials evaluating dietary supplement interventions (including tryptophan, vitamin D, omega-3, zinc, and antioxidants) on sleep quality in healthy populations and individuals with sleep disorders. Outcomes assessed were the Pittsburgh Sleep Quality Index (PSQI), sleep efficiency (SE), sleep latency (SL), total sleep time (TST), wake after sleep onset (WASO), and number of awakenings after sleep onset (NASO).
What was found
Across 28 randomized controlled trials, dietary supplement interventions significantly improved sleep metrics: reduced PSQI (MD: -0.70, 95% CI: -1.37 to -0.03, p < 0.05), increased SE (+2.58 min, 95% CI: 2.01 to 3.16, p < 0.00001), prolonged TST (SMD: +0.23, 95% CI: 0.04 to 0.43, p < 0.05), and shortened SL (SMD: -0.24, 95% CI: -0.37 to -0.10, p < 0.001) and WASO (SMD: -0.30, 95% CI: -0.48 to -0.12, p < 0.001). NASO showed a marginal reduction (MD: -1.57, 95% CI: -3.16 to 0.02, p = 0.05).
Why it matters
This review synthesizes clinical trial evidence demonstrating that targeted nutritional supplementation can produce modest improvements across subjective sleep quality and objective sleep architecture.
Limits
The abstract does not report the total participant sample size, specific supplement dosages, or intervention durations. Pooling distinct dietary supplements (tryptophan, vitamin D, omega-3, zinc, antioxidants) introduces substantial heterogeneity, and effect sizes were generally modest.
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