What evidence? There is really no evidence,
as far as I know, that people EATING A BALANCED
DIET need any supplements. There is really no
evidence, as far as I know, that taking more
vitamins than required to prevent diseases due
to deficiency (scurvy, rickets, beriberi etc)
provides any benefit (such as avoiding cancer,
or the common cold, or the flu, or AIDS).

More and more? Are you sure this isn't misinformation
planted by the folks who sell the pills?

Don't get me wrong; I took supplements for years and
then didn't take them for years. I didn't notice any
difference. I'm certainly not opposed to taking supplements,
medication or whatever. In fact, I would be dead now
if not for chemotherapy (non-Hodgkin lymphom; not influenced
by diet), so I'm all for taking synthetic stuff if it helps.