Is B12 useful for Sport?

Whether vitamin B12 is useful for sport depends on the individual's status. B12 is crucial for red blood cell formation, energy metabolism, and nerve function—all processes that indirectly support athletic performance. However, evidence indicates that supplementation in athletes without a proven deficiency does not significantly enhance performance. A B12 deficiency (common in vegans, people with gastrointestinal issues, or older adults) can lead to fatigue, reduced endurance, and increased injury risk. In such cases, targeted supplementation is beneficial. The evidence for a general ergogenic effect is moderate, based mainly on observational studies and mechanistic reasoning. A blood test (e.g., holotranscobalamin) can clarify individual status. Safety note: B12 is water-soluble and generally safe, but unnecessary supplementation offers no advantage. For most athletes consuming a balanced diet including animal products, additional B12 is not needed. Always address underlying causes of deficiency rather than relying on supplements alone.