The answer depends on the the work environment and the amount/type of jewellery. An employee is a representative of the company they work for. Employers want a clean, friendly look and a safe work environment. Unless the interview is for employment at a biker shop, tattoo/piercing parlour, magic shop, etc., it is best to avoid:
* Skull rings
* Dangly bracelets which can get caught in equipment or annoy co-workers with jangling noises
* Ear/nose ring combos
* Nose jewellery that dangles or large studs
* Jewellery that is worn in layers or is apt to hook on things
Tastefully subtle is best in jewellery for either gender. As with everything else, moderation is always best.
PS - Earlobe gages and nose hoops are distracting and can make customers uncomfortable. This can be a deterrent for employers, as well.