Hi Dannybex. 2 years - lol - now that's procrastinating.
I looked at my test and it says Amino Acids (FMV). FMV = First Morning Void, which means urine. There are also creatinine markers at the bottom of the page, which is something measured in urine.
However, there are two versions of the Nutreval, one is FMV and the other I think is all done by the blood. On another section of my test (Fatty Acids) it says RBCs, which is red blood cells. So basically you should be able to tell by whether it says FMV or RBC in the title of the page or section.