tuneTypical Dose
50–100 mg thiamine HCl for general use, or 150–600 mg benfotiamine (neuropathy)
Vitamin
Vitamin B1
Thiamine
Evidence TierAWADA NOT PROHIBITED
watchEffect Window
Acute (days) for deficiency reversal. Weeks for neuropathy improvement
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Vitamin B1 (thiamine) is a cofactor for carbohydrate metabolism and nerve function. It is used to correct deficiency and to support neuropathy and energy symptoms in at-risk groups.
Thiamine correction treats deficiency syndromes such as beriberi and Wernicke-related neurologic impairment and improves energy and neurologic function. Thiamine derivatives such as benfotiamine show evidence for reducing diabetic neuropathy symptoms and improving some glycation biomarkers. Minority benefits include improved cardiac function in some heart failure contexts. Benefits are strongest in alcoholism, malabsorption, or low intake states.
Thiamine pyrophosphate is a coenzyme for pyruvate dehydrogenase and transketolase, essential for carbohydrate metabolism and the pentose phosphate pathway. Benfotiamine activates transketolase to divert glycolytic intermediates away from AGE-forming pathways.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Reverses beriberi and Wernicke-Korsakoff deficiency symptoms
Secondary Outcomes
- Benfotiamine reduces diabetic neuropathy symptoms
- Inhibits Advanced Glycation End-product (AGE) formation
Safety
Contraindications and Interactions
Contraindications
- None established for oral use
Side effects
- None at typical oral doses
Interactions
- No significant drug interactions known
Avoid if
- No populations need to avoid oral thiamine
Evidence
Study-level References
vitamin-b1-SRC-001Randomized controlled trial
Sourceopen_in_newStracke H, et al. *Benfotiamine in diabetic polyneuropathy (BENDIP): results of a randomised, double blind, placebo-controlled clinical study.* Exp Clin Endocrinol Diabetes. 1996.
Population: Diabetic patients with peripheral neuropathy
Dose protocol: Benfotiamine 300–600 mg/day for 6 weeks
Key findings: Benfotiamine significantly improved Neuropathy Symptom Score compared to placebo.
Notes: Key trial establishing benfotiamine efficacy in neuropathy.
Paper content
Benfotiamine significantly improved Neuropathy Symptom Score compared to placebo.
vitamin-b1-SRC-002Narrative review
Sourceopen_in_newLonsdale D. *A review of the biochemistry, metabolism and clinical benefits of thiamin(e) and its derivatives.* Evid Based Complement Alternat Med. 2006.
Population: General; emphasis on deficiency states and derivative forms
Dose protocol: Review of multiple dosing regimens
Key findings: Comprehensive overview of thiamine biochemistry. Supports benfotiamine superiority for intracellular delivery and neuropathy.
Notes: Useful background reference, not a primary efficacy study.
Paper content
Comprehensive overview of thiamine biochemistry; supports benfotiamine superiority for intracellular delivery and neuropathy.
vitamin-b1-SRC-003Expert consensus / regulatory reference
Sourceopen_in_newWHO Model List of Essential Medicines (thiamine listed for deficiency treatment).
Population: Global populations at risk for thiamine deficiency
Dose protocol: Standard therapeutic dosing
Key findings: Thiamine recognized as essential for preventing and treating deficiency states.
Notes: Regulatory validation of thiamine's essential status.
Paper content
Thiamine recognized as essential for preventing and treating deficiency states.
vitamin-b1-SRC-004Randomized, double-blind, placebo-controlled phase II trial.
Sourceopen_in_newZiegler D, Sipola G, Strom A, et al. Effects of benfotiamine treatment over 12 months on morphometric, neurophysiological and clinical measures in type 2 diabetes patients with symptomatic polyneuropathy (BOND study). BMJ Open Diabetes Res Care. 2026;14(1):e005773. doi:10.1136/bmjdrc-2025-005773. PMID:41571333.
Population: Type 2 diabetes patients with mild-to-moderate symptomatic diabetic sensorimotor polyneuropathy.
Dose protocol: Benfotiamine 300 mg twice daily (600 mg/day) for 12 months in type 2 diabetes with symptomatic polyneuropathy
Key findings: No significant effects on corneal nerve fiber length, neurophysiological measures, or clinical neuropathy endpoints. Neuropathy Symptom Score showed a non-significant trend (P=0.098). Benfotiamine raised thiamine analytes and was well tolerated.
Notes: Important negative trial that tempers earlier short-term positive findings. Suggests symptomatic benefits may not translate to objective neuroanatomical improvement over 12 months.
Paper content
The BOND study was a 12-month double-blind RCT of benfotiamine 600 mg/day versus placebo in 57 type 2 diabetes patients with symptomatic polyneuropathy. The study found no significant effects on the primary morphometric endpoint (corneal nerve fiber length) or on multiple neurophysiological and clinical measures. Only the Neuropathy Symptom Score showed a trend toward improvement (P=0.098). Benfotiamine did successfully raise thiamine analyte concentrations and was well tolerated. This is an important negative trial that tempers the earlier positive shorter-term findings for benfotiamine in diabetic neuropathy, suggesting that the symptomatic benefits observed in 6-week trials may not translate to objective neuroanatomical improvement over 12 months.
vitamin-b1-SRC-005Multicenter randomized clinical trial.
Sourceopen_in_newReyes-Alvarez MT, Chavez Minano V, Garro-Barrera B, et al. Hydroxocobalamin, thiamine, and pyridoxine as an adjunct to standard treatment in chronic low back pain: a randomized clinical trial. Med Clin (Barc). 2026. doi:10.1016/j.medcli.2025.107307. PMID:41604864.
Population: Patients with chronic mechanical low back pain across six Peruvian centers.
Dose protocol: Injectable B vitamins (thiamine, hydroxocobalamin, pyridoxine) plus NSAIDs vs NSAIDs alone in chronic low back pain
Key findings: 84% of B-vitamin group achieved 30% or greater pain reduction versus 64% in controls (RR 1.31, P=0.007).
Notes: Combination formulation makes it difficult to isolate thiamine's individual contribution. Supports B vitamin adjunct use for chronic pain.
Paper content
This multicenter randomized trial across six Peruvian centers tested injectable B vitamins (B12, B1, and B6) as an adjunct to standard NSAID treatment in chronic mechanical low back pain. The B-vitamin group had a significantly higher responder rate, with 84% achieving at least 30% pain reduction compared to 64% in the NSAID-only group. This supports the long-standing use of combined B vitamins for neuropathic and musculoskeletal pain, with pyridoxine (B6) contributing to the combination through its role in neurotransmitter synthesis and nerve function. The injectable route and combination formulation make it difficult to isolate the specific contribution of B6 alone.