Associations between supplement intake and sleep quality among general population
Näytönastekatsaukset
2.6.2026
Level of evidence: C
Vitamin D, amino acids, melatonin, probiotics, and L-theanine supplementation may increase the sleep quality compared with placebo among general population.
Although the evidence is based on randomized controlled trials and meta-analyses, the risk of bias, inconsistent results, indirectness in relation to insomnia treatment, imprecision, and potential publication bias significantly reduce the certainty. The overall evidence is limited by small sample sizes, short intervention periods, heterogeneity between studies, and a reliance on self-reported sleep measures.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias [Table «Additional comments for included studies»2 Additional comments] |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis | |||||
| «Abboud M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients 2022;14(5): »1 | SR, MA | adults Iran, USA, New Zeeland, Turkey, China, Netherlands | interventions studies | Sleep quantity, quality (PSQI) | Moderate |
| «Chan V, Lo K. Efficacy of dietary supplements on improving sleep quality: a systematic review and meta-analysis. Postgrad Med J 2022;98(1158):285-293 »2 | SR, MA | Adults Malaysia, Iran, United Kingdom, Australia, Israel, Turkey, USA; Germany, Italy, France | RCTs | Different sleep quality parameters | Moderate |
| «Santi D, Debbi V, Costantino F, et al. Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis. Clocks Sleep 2023;5(4):770-792 »3 | SR, MA | Children, adults (probiotic only among adults) N/A | RCTs | Different sleep quality parameters | Moderate |
| «Bulman A, D'Cunha NM, Marx W, et al. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. Sleep Med Rev 2025;81():102076 »4 | SR, MA | All ages Japan, Asia, USA, Europe, Australia | RCTs | Different sleep quality parameters | Low |
| Reference | Comments |
|---|---|
| «Abboud M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients 2022;14(5): »1 | The nature of studies, risk of bias. |
| «Chan V, Lo K. Efficacy of dietary supplements on improving sleep quality: a systematic review and meta-analysis. Postgrad Med J 2022;98(1158):285-293 »2 | Risk of bias, partially blinding incomplete, some studies with industry funding |
| «Santi D, Debbi V, Costantino F, et al. Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis. Clocks Sleep 2023;5(4):770-792 »3 | Small sample size, risk of bias. |
Results
| Reference | Number of studies and number of patients (I/C) | Absolute number of events (%) I | Absolute number of events (%) C | Relative effect (95% CI) |
|---|---|---|---|---|
| Level of evidence: low *Statistically significant The quality of evidence is downgraded due to (study limitations, inconsistency, indirectness, imprecision, publication bias). The quality of evidence in upgraded due to large or very large effects, dose-response gradient, effect of plausible residual confounding). I= intervention; C=comparison; CI=confidence interval: MD=mean difference; SMD Standard mean difference | ||||
| «Abboud M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients 2022;14(5): »1 | Vitamin D supplementation 3 studies (111/112) | N/A | N/A | MD -2.33 * (-3.09 to -1.57) moderate |
| «Chan V, Lo K. Efficacy of dietary supplements on improving sleep quality: a systematic review and meta-analysis. Postgrad Med J 2022;98(1158):285-293 »2 | Amino acid supplementation 2 studies (40/38) | N/A | N/A | MD -1.27 * (-2.35 to -0.20 moderate |
| Melatonin supplementation 7 studies (205/199) | N/A | N/A | MD −1.21 * (-2.17 to -0.24) low | |
| Vitamin D 4 studies (200/202) | N/A | N/A | MD −1.63 * (-3.15 to -0.10) low | |
| Omega-3 2 studies (73/63) | N/A | N/A | MD 0.13 (-0.84 to 1.09) very low | |
| «Santi D, Debbi V, Costantino F, et al. Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis. Clocks Sleep 2023;5(4):770-792 »3 | Probiotics 8 studies (274/261) | N/A | N/A | MD -0.40 * (-0.79 to -0.02) moderate |
| «Bulman A, D'Cunha NM, Marx W, et al. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. Sleep Med Rev 2025;81():102076 »4 | L-theanine 12 studies (454/444) | N/A | N/A | SMD 0.44 * (0.04 to 0.84) moderate |
References
- Abboud M. Vitamin D Supplementation and Sleep: A Systematic Review and Meta-Analysis of Intervention Studies. Nutrients 2022;14(5): «PMID: 35268051»PubMed
- Chan V, Lo K. Efficacy of dietary supplements on improving sleep quality: a systematic review and meta-analysis. Postgrad Med J 2022;98(1158):285-293 «PMID: 33441476»PubMed
- Santi D, Debbi V, Costantino F, et al. Microbiota Composition and Probiotics Supplementations on Sleep Quality-A Systematic Review and Meta-Analysis. Clocks Sleep 2023;5(4):770-792 «PMID: 38131749»PubMed
- Bulman A, D'Cunha NM, Marx W, et al. The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis. Sleep Med Rev 2025;81():102076 «PMID: 40056718»PubMed