Home » The normal value of CPK in serum varies between Enzymology MCQs The normal value of CPK in serum varies between January 22, 2022 11 Views Q. The normal value of CPK in serum varies between A. 4–60 IU/L B. 60–250 IU/L C. 4–17 IU/L D. > 350 IU/L Answer: 4–60 IU/L