This study aimed to compare the vitamin B12 and folate status of recreational endurance athletes and inactive controls by modern biomarkers. In 72 athletes (38 ± 7 y) and 46 inactive controls (38 ± 9 y) serum levels of vitamin B12, methylmalonic acid (MMA), holotranscobalamin II (holoTC), folate, and homocysteine (Hcy) were measured. Vitamin B12 and folate levels of both groups were comparable, but athletes had higher median (25.−75. percentile) MMA [242 (196 to 324) versus 175 (141 to 266) nmol/L] and holoTC concentrations [67 (52 to 93) versus 55 (45 to 70) pmol/L] than controls. Hcy was slightly lower in athletes [9.2 (7.2 to 12.6) versus 10.8 (8.9 to 12.9) nmol/L]. In controls, we found the following correlations: vitamin B12 and MMA (r = −0.38), vitamin B12 and holoTC (r = 0.51), MMA and holoTC (r = −0.36). In athletes, MMA did not correlate with vitamin B12 and holoTC. Our data suggests an altered vitamin B12 metabolism in recreational athletes that needs further investigation.
Herrmann, Obeid, and Herrmann are with the University Hospital of Saarland, Dept of Clinical Chemistry and Laboratory Medicine, Homburg/Saar 66421,Germany. Scharhag and Kindermann are with the Institute of Sports and Preventive Medicine, University of Saarland, Saarbruecken 66123, Germany.