Supplement
Thiamine, also called vitamin B1, is a vitamin the body needs to turn food into energy and keep nerves working. Researchers mostly look at it for small blood vessel damage, where the evidence is moderate, and the clearest finding was that premenstrual symptoms improved in one large trial of 344 people. Other findings were thin: blood pressure improved in a tiny diabetes study, and a heart failure trial found no clear difference in walking.
Sources: PMID 25363099
- Updated
- How we grade
- 3 studies cited
- Best evidence
- Grade B
- Conditions studied
- 4
- Outcomes
- 18
- Graded outcomes
- 0121
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| PMS Symptoms Large Improvement | Improves (the measure goes down) | Large effect | 1 study | 344 people | ||
Studies that measured pms symptoms | ||||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood Pressure Small Improvement | Improves (the measure goes down) | Small effect | 12 people | |||
| High-density lipoprotein (HDL) | Improves (the measure goes up) | 1 study | 12 people | |||
Studies that measured high-density lipoprotein (hdl) | ||||||
| C-Reactive Protein (CRP) | Improves (the measure goes down) | 12 people | ||||
| Low-density lipoprotein (LDL) | Improves (the measure goes down) | 12 people | ||||
| Total cholesterol | Improves (the measure goes down) | 12 people | ||||
| Triglycerides | Improves (the measure goes down) | 12 people | ||||
Prediabetes
- Blood Pressure: improves
- High-density lipoprotein (HDL): improves
- C-Reactive Protein (CRP): improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Blood Pressure Small Improvement | Improves (the measure goes down) | Small effect | 12 people | |||
| High-density lipoprotein (HDL) | Improves (the measure goes up) | 1 study | 12 people | |||
Studies that measured high-density lipoprotein (hdl) | ||||||
| C-Reactive Protein (CRP) | Improves (the measure goes down) | 12 people | ||||
| Low-density lipoprotein (LDL) | Improves (the measure goes down) | 12 people | ||||
| Total cholesterol | Improves (the measure goes down) | 12 people | ||||
| Triglycerides | Improves (the measure goes down) | 12 people | ||||
Heart Failure
- 6-Minute Walking Test Performance
- Left Ventricular Ejection Fraction: improves
- End-Diastolic Volume: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| 6-Minute Walking Test Performance No effect | NoneNo effect | 274 people | ||||
| Left Ventricular Ejection Fraction | Improves (the measure goes up) | 1 study | 274 people | |||
Studies that measured left ventricular ejection fraction | ||||||
| End-Diastolic Volume | Improves (the measure goes up) | 274 people | ||||
| Heart Failure Class | Improves (the measure goes up) | 274 people | ||||
| N-terminal Prohormone of Brain Natriuretic Peptide | Improves (the measure goes up) | 274 people | ||||
Key findings
- PMS SymptomsImproves (the measure goes down)
- Blood PressureImproves (the measure goes down)
- 6-Minute Walking Test Performance
Shop the evidence-backed picks
Third-party tested Thiamine (Vitamin B1) products, in the forms the graded studies used where we can match them.
- Grade B
Links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Fullscript asks for a free account before it shows its catalog and prices. Full disclosure
Studies cited
3 studies from PubMed
- The impact of thiamine supplementation on blood pressure, serum lipids and C-reactive protein in individuals with hyperglycemia: a randomised, double-blind cross-over trial
- The effects of vitamin B1 on ameliorating the premenstrual syndrome symptoms
- Role of Thiamine Supplementation in the Treatment of Chronic Heart Failure: An Updated Meta-Analysis of Randomized Controlled Trials.