The management of heart failure (HF) represents a significant challenge for both patients as well as the healthcare system in industrialized countries. Thiamin is a required coenzyme in the energy-producing reactions that fuel myocardial contraction. Therefore, thiamin deficiency (TD) may contribute to myocardial weakness by limiting the energy available for contraction. Previous studies have reported a wide range in the prevalence of TD in patients with HF (3–91 %). The impact of thiamin supplementation in patients with HF is inconclusive. Studies conducted to date are limited by their small sample size, indirect methods of assessing thiamin concentration, methodological inconsistencies, use of impractical means of thiamin supplementation, a focus on hospitalized patients, and lack a robust technique for the assessment of cardiac function. Future large prospective studies and randomized controlled trials are needed to improve our understanding of any change in nutritional requirements associated with chronic disease as well as the clinical benefit of supplementation.