How Do Animals Naturally Obtain Creatine?

The process of how animals produce creatine involves a crucial step where guanidinoacetate (GAA) obtains a methyl group. This methyl group is acquired through the transmethylation cycle, with the assistance of S-Adenosyl Methionine (SAM), as depicted in Figure 1. This mechanism was first elucidated on November 26, 2020, and it plays a fundamental role in understanding the biosynthesis of creatine in animals.

Creatine is a naturally occurring compound that is produced within the bodies of vertebrates. It is primarily stored in skeletal muscle tissue, accounting for approximately 95% of the total creatine content in the body. In addition to skeletal muscle, lower concentrations of creatine can also be found in other vital tissues such as cardiac and smooth muscle, the brain, the retina, macrophage cells, and spermatozoa. This distribution of creatine across various tissues underscores its importance in multiple physiological processes (Bürger, 1919; Meador et al., 1968; Wyss and Kaddurah-Daouk, 2000). This diverse presence of creatine highlights its significance in supporting various cellular functions throughout the body.

Creatine is an essential natural compound found in the bodies of animals, and it plays a pivotal role in their energy metabolism. Unlike many other nutrients, creatine is primarily stored within the muscles, where it serves as a crucial source for rapidly replenishing adenosine triphosphate (ATP), which is vital for supplying energy to the muscles. This unique function of creatine ensures that animals have a readily available energy source for their muscle activities.