Can vitamin b2 cause a false positive on a drug test?

No: I thought this was a strange question, but in researching it found out that this is claimed on some websites. However, I am quite certain that b2 does not cause a false positive on drug tests. It can make your urine bright yellow & some who drink a lot of fluids to dilute their urine before a test will sometimes take b2 so the urine looks yellow rather than clear. Will not cause false positive.