Athletes deficient in B-vitamins may perform worse during high-intensity exercise and have less ability to repair and build muscle than individuals with nutrient-rich diets.

B vitamins, including thiamin, riboflavin, B6, B12, and folate, are required by the body for proper conversion of proteins and sugars into energy. B vitamins are also utilized during the production and repair of cells, including red blood cells.

In a study, researchers analyzed both diet and athletic performance of several elite and collegiate athletes, as well as those of less competitive individuals. Even a marginal deficiency in these nutrients negatively influenced the ability of the athletes’ bodies to repair, operate efficiently, and fight disease. Exercise-induced stress, changes in body tissues resulting from training, increased loss of nutrients (in sweat, urine, and feces), and the additional nutrients needed to repair and maintain higher levels of lean tissue mass may all affect an individual’s B-vitamin requirements.

The researchers noted that current national B-vitamin recommendations for active individuals may be inadequate, and chronic deficiencies could jeopardize athlete’s abilities and long-term health. Athletes, as well as individuals with poor and restricted diets, should consider a multivitamin and multimineral supplement to ensure B-vitamin adequacy.

Kathleen Woolf; Melinda M. Manore. Int J Sport Nutr Exerc Metab 2006 16:453-484.