I've read conflicting views on whether or not Vitamin B2 can be a false positive for THC. On this website and at erowid.com, it is recommended that one take Vitamin B to keep their pee yellow when diluting their pee. However, on other sites, I found Riboflavin (Vitamin B2) can be a false positive. Anyone know the facts? Also, should I be worried about failing the test? Height: 5'9" Weight: 180 Estimated metabolism: normal Smoking history for the last 30 days: I smoked about 4 times a week for about 6 months. I was arrested and then didn't smoke for a month. I smoked once and then went another month without smoking. A month ago I smoked one more time. It has been a month and my test is tomorrow. How often you work out (if you do): About once a week... regular exercise daily ---I do not have time before my test to get a home test--- Thanks.