Our bodies don't make a lot of vitamins; some, like C & D, we don't make any of, so we must get them from outside sources like food or supplements (sunshine in the case of D - when that's safe, of course). Some supplements we do make naturally.

However, if there's a medical need to take some, whether we're not manufacturing them, not enough of them, aren't processing them sufficiently.... Whatever the reason, if we need more to address some particular issue (like PN) then IMO the risk of not taking them outweighs the risk of suppression.

Some people (like type 1 diabetics) are going to need supplementation for life. Our bodies make R-Lipoic Acid, and it's essential for life. I may be making enough of it to survive, but if taking more helps my PN symptoms, I'm going to take it - for however long I need to - including for life.

Everyones' dietary needs change as they age; and everyone ages/changes at different rates. I view the vitamins & supplements I take as part of my diet - like food. If I stop eating something, and become deficient in it, it doesn't matter to me if it's a vitamin, or supplement, or protein, or carbohydrates, or water, etc. I need all of these things to keep myself alive and well (as possible).

Doc