medicine-Diabetes mellitus-introduction

in the 17th video of medicine-Diabetes mellitus-introduction, c peptide levels you said are <1.8ng/dl but in books it is written in ‘ml’

pmol/L, nmol/L, ng/mL, ng/dL, ng/100mL, ng%, ng/L, µg/L are all units that can be used by laboratories to report C-peptide levels.

Thank you.