PlainPill

B-Complex Vitamins

People mainly take B-Complex Vitamins for anxiety, energy. Based on 7 first-hand reports and 5 meta-analyses & systematic reviews in the medical literature. Ranked #1451 of 1,974 overall.

9
User score
Mostly negative
0% positive14% mixed29% negative57% unclear

Of reports that state an outcome, 0% are positive.

Clinical research
BModerate research base
5
meta-analyses
5
RCTs
324
papers

What B-Complex Vitamins does, according to users

Of the people who reported each effect, the share who said it got better.

betterno changeworse

What the research says

Systematic reviews and meta-analyses from PubMed, with their published conclusions.

BModerate research base

At least one meta-analysis, or 5+ randomized controlled trials. The grade measures how much human research exists — read the conclusions below for what it found.

Nutrients · 2022 · Meta-analysis / systematic review
Vitamin Supplementation and Dementia: A Systematic Review

Conclusion: The findings of this systematic review suggest that supplementation of B Complex vitamins, especially folic acid, may have a positive effect on delaying and preventing the risk of cognitive decline. Ascorbic acid and a high dose of vitamin E, when given separately, also showed positive effects on cognitive performance, but there is not sufficient evidence to support their use. The results of vitamin D supplementation trials are not conclusive in assessing the potential benefits that vitamin D might have on cognition.

PubMed 35268010 ↗
BMC Complement Altern Med · 2017 · Meta-analysis / systematic review
Nutritional supplements and herbal medicines for women with polycystic ovary syndrome; a systematic review and meta-analysis

Conclusion: There is no high quality evidence to support the effectiveness of nutritional supplements and herbal medicine for women with PCOS and evidence of safety is lacking. High quality trials of nutritional supplements and herbal medicines examining menstrual regulation and adverse effects in women with PCOS are needed.

PubMed 29178904 ↗
Alzheimer Dis Assoc Disord · 2009 · Meta-analysis / systematic review
Cardiovascular risk factors and incident Alzheimer disease: a systematic review of the literature

Conclusion: In this review, the evidence that single clinically defined cardiovascular risk factors are significantly associated with incident AD is inconsistent at best. The strength of the association of cardiovascular risk factors and AD can be influenced greatly by changing the parameters of measurement of risk factors and by identifying interactions between the factors.

PubMed 18703981 ↗
Nutr Hosp · 2012 · Meta-analysis / systematic review
[Effect of folate and related nutrients on cognitive function in older people; systematic review]

Conclusion: This review doesn't support a benefit from folic acid supplementation on cognitive function in the elderly. Whereas low folate serum levels may be related to increased risk of cognitive impairment and high levels associated with low levels of vitamin B12 can contribute a further deterioration, it is suggested as precautory measure to re-examine the present level of food fortification with folic acid to maximize benefits and limit potential risks.

PubMed 22566307 ↗

Dosage people report

As stated by users — not a recommendation. Follow the label or your doctor.

morningas reported

Reported side effects

How often each side effect came up across all reports.

No side effects reported so far.

What users say

Verbatim quotes, shortened only — each links to the original discussion.

“Magnesium & the B-vitamins calm me down instantly.”
Source discussion ↗
“I have read about kudzu root and B-complex vitamins (the family member drinks mostly beer)”
Source discussion ↗
“Nicotinamide/Nicotinic Acid/Niacin (B3) creates NAD^+ which is essential for the production of BH4, a cofactor for Dopamine synthesis.”
Source discussion ↗
“Soon, even B-complex vitamins stopped working. Not just magnesium, but all B vitamins (B6, B1, and others) became ineffective.”
Source discussion ↗
“way back I tried some B-complex vitamins and L-theanine which helped but not that much.”
Source discussion ↗
Top discussions (5)

Other options for anxiety

User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate