Limited evidence. Direction: No effect.
C LimitedSubjective outcome only
Rubric condition met: Three meta-analyses null or non-significant on mood-symptom scales, with a positive trend in one; mixed small trials. C, none; N not proposed because the B-complex meta-analysis trends positive (p = 0.07)
In the Bayer-co-funded meta-analysis of supplements with at least three B vitamins, the benefit for low-mood symptom scales did not reach significance (SMD 0.15, p = 0.07) and there was no effect on anxiety. A meta-analysis of vitamin B12 alone or B complex found no overall effect on measures of low-mood symptoms, nor did a 2024 vitamin B12 meta-analysis (3 trials). A 3-month vitamin B complex trial in workers found less dejected mood but no change in other mood measures.
| Study | Year | Design | Participants | Result |
|---|---|---|---|---|
| Stough 2011 | 2011 | RCT | 60 | result not recorded |
| Young 2019 | 2019 | meta-analysis | 2015 | result not recorded |
| Markun 2021 | 2021 | meta-analysis | 6276 | result not recorded |
| Alzahrani 2024 | 2024 | meta-analysis | not recorded | result not recorded |
Alzahrani H. Assessment of Vitamin B12 Efficacy on Cognitive Memory Function and Depressive Symptoms: A Systematic Review and Meta-Analysis Cureus, 2024. PMID 39655146
Stough C, Scholey A, Lloyd J. The effect of 90 day administration of a high dose vitamin B-complex on work stress Hum Psychopharmacol, 2011. PMID 21905094
Young LM, Pipingas A, White DJ. A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' Individuals Nutrients, 2019. PMID 31527485
Markun S, Gravestock I, Jäger L. Effects of Vitamin B12 Supplementation on Cognitive Function, Depressive Symptoms, and Fatigue: A Systematic Review, Meta-Analysis, and Meta-Regression Nutrients, 2021. PMID 33809274
Search (): (B vitamin*[ti] OR vitamin B[ti]) AND (stress[tiab] OR mood[tiab] OR depressive[tiab]) AND (meta-analysis[pt] OR systematic review[pt])
