Vitamin D Supplementation Influences Ultramarathon-Induced Changes in Serum Amino Acid Levels, Tryptophan/Branched-Chain Amino Acid Ratio, and Arginine/Asymmetric Dimethylarginine Ratio

Exercise affects serum levels of amino acids and their metabolites, with important metabolic consequences. Since vitamin D impacts skeletal muscle protein degradation, we hypothesised that it would also impact exercise-induced changes in acid the arginine influencing body’s ability to synthesise NO. Accordingly, analysed effect a single high-dose supplementation on various ultramarathon runners. Thirty-five male amateur runners were assigned supplemented group, administered 150,000 IU vegetable oil 24 h before run (n = 16), or control (placebo) group 19). Blood was sampled before, immediately after, after run. Changes some distinct two groups. The asymmetric dimethyl significantly decreased increased later not affected by supplementation. symmetric both groups but lower than placebo dimethylamine as compared group. In conclusion, methylated metabolites.