Next year I am going for my medical and planning to quit with the supplements, but I am wondering if using them would affect the urine and blood examination.
You make it sound as if you are using something secret or surreptitious !
Dietary supplements are unlikely to have any effect at all on a medical to determine professional fitness.
The human body works best on a normal healthy balanced diet, and, let's face it, eating can be very pleasurable too ! Why "top up" any particular vitamin or mineral if there is no evidence whatever that it is deficient ? Would you pour more oil into your car ( or plane ! )engine if the dipstick level was totally "normal" ?
It's also costing you dear, of course, because you have bought the supplements ! Any which is surplus to the body's requirements is not "saved for a rainy day", it ends up in the public sewer system ! Why not just pour your money down the drain in the first place ?
Kali orexi !