Evidence check: FUT2 in the context of Sport

FUT2 (fucosyltransferase 2) determines secretor status and influences vitamin B12 absorption. Some studies link FUT2 variants to B12 levels, which could theoretically affect energy metabolism and red blood cell production in athletes. However, there is no direct, robust evidence from sport-specific studies linking FUT2 variants to performance outcomes. The evidence is purely mechanistic: B12 is crucial for energy and erythropoiesis, but the impact of FUT2 polymorphisms on athletic performance is not supported by human trials. Consumer DNA tests often include FUT2 in nutrient metabolism panels, but the relevance for sport is weak. A blood test for B12 status would be more actionable. Caution: having a FUT2 variant does not guarantee deficiency or performance impairment.