People often talk about how cynical of the medical profession they are, yet in Australia the public spends 4 TIMES the amount of money out-of-pocket on supplements and unproven 'natural' products compared to prescription medication.
It is unfortunate that the multivitamin industry has managed to convince so many that they are somehow deficient in things. Even more troubling, is that a number of vitamins are clearly dangerous at high-levels - for example, I've seen a number of people double-dosing vitamin B supplements 'for energy' and then become B6 toxic. It causes a painful neuropathy, which fortunately is usually reversible but can be permanent if not recognised.