Conclusion: This meta-analysis suggests that B vitamin supplementation is associated with slowing of cognitive decline, especially in populations who received early intervention and intervention of long duration; the study also indicates that higher intake of dietary folate, but not B12 or B6, is associated with a reduced risk of incident dementia in non-dementia aged population. Given the prevalence of dementia cases in many countries with aging populations, public health policies should be introduced to ensure that subgroups of the population at risk have an adequate B vitamin status.
Vitamin B Complex side effects
Across 212 first-hand reports, people mentioned a side effect 9 times (about 4 per 100 reports). The most common: brain fog, nerve issues, derealization. User reports show what people notice — they can't tell you whether Vitamin B Complex is safe for you.
Reported side effects
brain fog2
nerve issues1
derealization1
tingling and1
paranoia1
vivid dreams1
hallucinations1
too strong1
What got worse for some people
In their own words
“I tried so many things for depression like saffron rhodiola tyrosine omega 3 methylfolate B12 taurine theanine NAC inositol b complex magnesium nothing helps it.”
“Earlier today I took a vitamin B complex supplement that includes all of the B vitamins including 100 mg of biotin...started feeling paranoid all of a sudden.”
“Every time I take a Vitamin B Complex (Thorne), I get brain fog. I've tested this multiple times and it always results in brain fog.”
“never actually found anything that helped. Not one thing... Supplements I've tried include fish oil pills, htp-5, fluoxetine, effexor, adderall, ritalin, vitamin b complexes, and st johns wort.”
“B-complex has greatly helped with my depression and anxiety...I was taking B12 and B6...everyday I noticed I felt tired and on top of that my sight was becoming a bit blurt.”
“I couldn't discern any significant changes in my energy levels, mood, or overall well-being.”
Is Vitamin B Complex safe? What the research covers
AResearch: Strong237 meta-analyses · 64 randomized trials on PubMed
Nutr Rev · 2022
B vitamins and prevention of cognitive decline and incident dementia: a systematic review and meta-analysisNutrients · 2019
A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' IndividualsConclusion: The review provides evidence for the benefit of B vitamin supplementation in healthy and at-risk populations for stress, but not for depressive symptoms or anxiety. B vitamin supplementation may particularly benefit populations who are at risk due to (1) poor nutrient status or (2) poor mood status.