The B-complex vitamins related to energy metabolism and their role in exercise performance: A narrative review

Abstract

ObjectiveThe present review aims to clarify the relationship of thiamine, riboflavin, and niacin to exercise performance. NewsThe B vitamins thiamine (vitamin B1), riboflavin (vitamin B2), and niacin (vitamin B3) are hydrophilic vitamins that play a fundamental role as coenzymes in enzymatic reactions of energy metabolism. The increase in energy demand during physical exercise can alter the requirements for these vitamins. Prospects and projectsThis study is a narrative review which selected and analyzed studies that investigated how the vitamins thiamine, riboflavin, and niacin can affect sports performance in both humans and experimental animal models. ConclusionThe research shows that supplementation with these vitamins does not necessarily produce ergogenic effects. Despite their fundamental roles in anabolic pathways, only the intake of thiamine-derivative substances showed some positive effects on exercise performance and fatigue. Isolated riboflavin supplementation did not show positive effects, while there is evidence that high niacin intake can harm exercise performance. Some studies found an increase in excretion and a decrease in the blood levels of these vitamins after exercise, but the results are inconsistent. However, different pharmacokinetics, doses or dosing frequency, and administration route of the supplemented substances can influence the results. There are few studies of B-vitamins and exercise, and most of them are not recent. New studies, with systematically controlled protocols, are necessary to elucidate the real effects of thiamine, riboflavin, and niacin in exercise performance.