the vitamin/mineral nutritional supplements in the marketplace
today are made from USP (United States Pharmacopoeia) ingredients.
USP nutrients are synthesized chemical isolates, man-made
to mimic the chemical structure of their natural counterparts.
Their weakness is simply that they are isolates, which
is not how they're found in nature. Naturally, there isn't
just vitamin A or B or C, etc.; there is vitamin C (or A,
etc.) bound to a rich complex of associated food factors,
micro-nutrients, which make the vitamin C far more effective.
The word for this phenomenon is synergy. Some research
even suggests that certain synergistic factors may prove to
be even more important than the substance being imitated by
the USP process. The site already has information provided
by a grower of food-based supplements. for
more info click