Skip to main content
Evidence-Based Supplement Research
Evidence-Based Supplement Research
Pillser
Search
Sign UpLog In

Vitamin B1 and Improved Left Ventricular Ejection Fraction

Research synthesisVery low evidenceSmall effect3 studies · 1 beneficial · 2 neutral · 0 harmful

Across 3 studies, 1 reported a beneficial small-sized effect on left ventricular ejection fraction, while 2 found neutral effects. The beneficial finding came from a systematic review of 1755 patients with heart failure using a multi-ingredient supplement including thiamine, though the specific effect of vitamin B1 alone was not isolated. Studies primarily used doses of 50-100 mg/day in clinical populations, with a median duration of only 15 days, which is likely insufficient to assess cardiac remodeling effects.

  • Effective dose range: 50-100 mg/day
  • Studied populations: patients with heart failure, children with heart disease on diuretics, cardiac surgery patients

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. The only statistically significant finding came from a systematic review of multi-ingredient supplementation, making the independent effect of vitamin B1 unclear. Neither of the two RCTs found significant benefits, and their durations were very short (1-28 days). Many of the included studies did not reach statistical significance — effects may be smaller than the predominant direction suggests.

Generated Jul 13, 2026
Doses used in studies
  • mg/day: 50–100 (median 75, IQR 62.5–87.5) — 2 studies
Time to effect
Median: 2.1 weeks · IQR 8 days–3 weeks · Range 1 day–4 weeks — Reported in 2 of 3 studies
3 of 3 papers
Back to top