Vitamin B1 and Reduced Mortality Risk

Research synthesisVery low evidenceSmall effect3 studies · 0 beneficial · 3 neutral · 0 harmful

Across 3 studies, all reported neutral small-sized effects of vitamin B1 (thiamine) on reduced mortality risk in critically ill patients, including those with sepsis or septic shock. The evidence primarily comes from meta-analyses and systematic reviews involving intravenous thiamine, often in combination with other agents, with no statistically significant reductions in mortality observed.

Studied populations: critically ill patients, adults with sepsis/septic shock

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. None of the included studies reached statistical significance — effect may be smaller than the predominant direction suggests. Doses were not consistently reported, and many studies examined thiamine in combination with other agents (e.g., vitamin C, hydrocortisone), complicating isolation of thiamine-specific effects.

Generated Jul 13, 2026

Safety in these studies

Overall tolerabilityReported
Combination therapy with hydrocortisone, vitamin C, and thiamine (the HAT protocol) has been associated with reduced vasopressor duration but has not consistently improved survival or other major clinical endpoints, despite its apparent safety.
from: Beyond Fluid Therapy: The Role of Vitamin C, Steroids, and Thiamine in Sepsis Management.

3 of 3 papersPopulation:

Effect of intravenous thiamine administration on critically ill patients: A systematic review and meta-analysis of randomized controlled trials.
- 2024-11
- Meta-Analysis · n = 3,494
- Clinical nutrition (Edinburgh, Scotland) 43(11)
- - Nobuto Nakanishi
  - Yoshinobu Abe
  - Mizue Matsuo
  - Akihito Tampo
  - Kohei Yamada
  - Junji Hatakeyama
  - Minoru Yoshida
  - Ryo Yamamoto
  - Naoki Higashibeppu
  - Kensuke Nakamura
  - Joji Kotani
- PubMed: 39307094
- DOI: 10.1016/j.clnu.2024.09.002
5 Insights on
- Reduced Mortality Risk
- High evidence
- Clinical
Evidence suggested that thiamine administration resulted in little to no difference in mortality (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.75 to 1.06; Low CoE)
Effect
Neutral
Effect size
Small
Significant
No
Monotherapy or combinations? Intravenous vitamin C in sepsis and septic shock: An umbrella review of 31 systematic reviews.
- 2026-07-01
- Systematic Review
- PloS one 21(7)
- - Víctor Juan Vera-Ponce
  - Jhosmer Ballena-Caicedo
  - Lupita Ana Maria Valladolid-Sandoval
  - Fiorella E Zuzunaga-Montoya
  - Renzo Acosta-Porzoliz
  - Oriana Rivera-Lozada
  - Mario J Valladares-Garrido
- PubMed: 42384633
- DOI: 10.1371/journal.pone.0351072
3 Insights on
- Reduced Mortality Risk
- High evidence
- Clinical
Combinations (HAT and vitamin C+thiamine) did not reduce mortality
Effect
Neutral
Effect size
Small
Significant
No
Dose
Not specified
Beyond Fluid Therapy: The Role of Vitamin C, Steroids, and Thiamine in Sepsis Management.
- 2025-05-23
- Review
- Cureus 17(5)
- - Courage O Idahor
  - Olamide Ogunfuwa
  - Ndidiamaka Ogbonna
  - Augustina Adigwe
  - Omo A Ogbeide
- PubMed: 40546532
- DOI: 10.7759/cureus.84666
6 Insights on
- Reduced Mortality Risk
- Low evidence
Combination therapy with hydrocortisone, vitamin C, and thiamine (the HAT protocol) has been associated with reduced vasopressor duration but has not consistently improved survival or other major clinical endpoints, despite its apparent safety.
Effect
Neutral
Effect size
Small
Significant
No

Vitamin B1 and Reduced Mortality Risk

Effect of intravenous thiamine administration on critically ill patients: A systematic review and meta-analysis of randomized controlled trials.

Monotherapy or combinations? Intravenous vitamin C in sepsis and septic shock: An umbrella review of 31 systematic reviews.

Beyond Fluid Therapy: The Role of Vitamin C, Steroids, and Thiamine in Sepsis Management.