Creatine is a compound formed from several amino acids that is stored in high amounts in our muscles. It is produced in the kidneys and liver then transported to the muscle for uptake. Muscle creatine levels appear to be lower in vegetarians, indicating that the body's production of creatine may not be sufficient to replace the lack of a dietary source.
Creatine supplementation may benefit the performance of some athletes in some sports. More work is needed to fine-tune the likely situations, and athletes will need to experiment with creatine to determine whether they 'respond' to this strategy. This is best done under the supervision of a sports dietitian or sports scientist.