I believe that if you are eating a diet with plenty of unprocessed plant foods then you do not need a multi-vitamin, but you probably do need a B-12 supplement. Taking a multi-vitamin will not provide you with nutrition the way that plant foods will. You may get 15 or 20 nutrients from a pill, but whole plant foods will provide you with thousands of nutrients, many of which work synergistically. Long-term good health will not come from a pill. Now if you believe you need higher levels of certain nutrients for a chronic condition, I can understand that. Some PN sufferers benefit from B-6, B-12, multi-B vitamin, vitamin E, folate, magnesium, essential fatty acids, inositol, alpha-lipoic acid, evening primrose oil, borage oil, acetyl-l-arginine, etc.
Ron