Thiamine
Research reviewed: Up until 03/2026
Thiamine (Vitamin B1) is a dietary supplement with 9 published peer-reviewed studies involving 1,820 participants, researched for Energy Metabolism, Neurological Health, Cardiovascular Health and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Energy Metabolism
ModerateNeurological Health
StrongCardiovascular Health
ModerateCognitive Function
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Energy Metabolism
To investigate the effect of thiamine supplementation on fatigue and energy metabolism in healthy adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To investigate the effect of thiamine supplementation on fatigue and energy metabolism in healthy adults.
Dose
100 mg/day thiamine
Participants
120 healthy adults reporting fatigue
Duration
8 weeks
Results
Thiamine supplementation significantly improved self-reported fatigue scores and reaction times compared to placebo. Participants reported increased energy levels and improved concentration.
How They Measured It
Fatigue visual analogue scale, reaction time, cognitive performance tests
To assess evidence on thiamine status and energy-related outcomes in human populations.
Study Type
Systematic review
Purpose
To assess evidence on thiamine status and energy-related outcomes in human populations.
Dose
Various
Participants
Multiple cohorts across included studies
Duration
Various
Results
Thiamine deficiency consistently associated with fatigue, impaired pyruvate metabolism, and reduced ATP synthesis. Supplementation in marginally deficient individuals improved metabolic markers.
How They Measured It
Review of clinical trials and observational studies on thiamine and energy metabolism
Neurological Health
To evaluate high-dose thiamine supplementation in patients with Parkinson's disease.
Study Type
Randomised, controlled trial
Purpose
To evaluate high-dose thiamine supplementation in patients with Parkinson's disease.
Dose
100 mg thiamine IM twice weekly
Participants
50 patients with Parkinson's disease
Duration
3 months
Results
High-dose parenteral thiamine significantly improved motor scores on UPDRS and reduced fatigue in Parkinson's patients. Improvement was sustained over the study period.
How They Measured It
UPDRS motor score, fatigue severity scale
To determine whether thiamine supplementation prevents Wernicke encephalopathy in high-risk patients.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To determine whether thiamine supplementation prevents Wernicke encephalopathy in high-risk patients.
Dose
200 mg/day thiamine
Participants
100 hospitalised patients at risk for thiamine deficiency
Duration
4 weeks
Results
Thiamine supplementation significantly raised erythrocyte transketolase activity and prevented development of neurological deficiency signs in at-risk hospital patients.
How They Measured It
Neurological assessment, erythrocyte transketolase activity
To examine the relationship between dietary thiamine intake and cognitive decline in older adults.
Study Type
Prospective cohort study
Purpose
To examine the relationship between dietary thiamine intake and cognitive decline in older adults.
Dose
Dietary assessment of thiamine intake
Participants
4,447 older adults
Duration
5-year follow-up
Results
Higher dietary thiamine intake was independently associated with slower cognitive decline. Individuals in the highest thiamine intake tertile had significantly better MMSE scores at follow-up.
How They Measured It
Mini-Mental State Examination (MMSE), cognitive batteries, dietary recall
Cardiovascular Health
To assess the effect of thiamine supplementation in patients with chronic heart failure.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess the effect of thiamine supplementation in patients with chronic heart failure.
Dose
200 mg/day thiamine
Participants
67 patients with chronic heart failure on long-term diuretics
Duration
7 weeks
Results
Thiamine supplementation improved LVEF by an average of 22% compared to 13% in the placebo group. Significant improvement in exercise tolerance was also observed.
How They Measured It
Left ventricular ejection fraction (LVEF), exercise tolerance, serum thiamine
To evaluate thiamine supplementation effects on heart failure outcomes.
Study Type
Meta-analysis
Purpose
To evaluate thiamine supplementation effects on heart failure outcomes.
Dose
100-300 mg/day
Participants
Pooled data from 5 RCTs
Duration
Various
Results
Meta-analysis showed significant improvement in LVEF with thiamine supplementation in heart failure patients. Thiamine deficiency is common in this population due to diuretic use.
How They Measured It
Pooled analysis of RCTs measuring ejection fraction and clinical outcomes
Cognitive Function
To evaluate the effects of thiamine on cognition and mood in young adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate the effects of thiamine on cognition and mood in young adults.
Dose
50 mg/day thiamine
Participants
80 healthy young adults
Duration
2 months
Results
Thiamine supplementation significantly improved cognitive performance and mood scores. Improvements were most pronounced in attention and psychomotor speed tasks.
How They Measured It
Cognitive battery (attention, memory, reaction time), mood questionnaires
To investigate the role of thiamine in neuronal glucose metabolism and amyloid-beta production.
Study Type
In-vitro / preclinical study
Purpose
To investigate the role of thiamine in neuronal glucose metabolism and amyloid-beta production.
Dose
Cell culture experiments
Participants
Cell culture model
Duration
N/A
Results
Thiamine deficiency significantly increased amyloid-beta production and impaired neuronal glucose metabolism in cell culture models, suggesting a potential link between thiamine status and Alzheimer's disease pathology.
How They Measured It
Neuronal cell cultures, glucose metabolism assays, amyloid-beta quantification
Frequently Asked Questions
Common questions about Thiamine research
There are currently 10 peer-reviewed studies on Thiamine (Vitamin B1), involving 1,820 total participants. Research covers Energy metabolism, Neurological health, Cardiovascular health and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (8 human studies), and reported outcomes.
Thiamine has been researched for: Energy metabolism, Neurological health, Cardiovascular health, Cognitive function. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 8 out of 10 studies are human trials. Human trials carry more weight in our evidence scoring system.
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