Vitamins and supplements aren't mind altering.

Addictions tend to revolve around mind altering activities, whether drugs, alcohol, sex, exercise, gambling - people do these things and their brains are chemically affected in a way that makes them feel better or at least different.

If vitamins and supplements have any chemical effect in the brain that is reinforcing it would be so subtle as to be undetectable.

Even nicotine or caffeine which have short acting effects are strong enough to be recorded as having a chemical psychoactive effect in the brain.

If popping vitamins or supplements is addictive it would I would think need to revolve around some kind of placebo effect where the person taking them thinks he feels different and then reinforces that behavior by taking them to excess. Otherwise it would seem to me to be less reinforcing less addicting even than eating ("food high").

Actually while traveling I have cut back on what I bring and lately just bring maybe 11 or so versus ALL of them. On very short trips I have brought as few as 5 or so.