That is a very loaded question to answer and the answer may surprise many of you.  The majority of nutritional supplements are made by the same laboratories in China.  This is true with many of the lower priced nutritional supplements, but certainly not all of them.  Most of these supplements start with petroleum based products at their core.

There are many excellent nutritional supplements made in the United States or Europe that have higher quality standards they adhere to and many are composed of natural or organic ingredients.  Let's face it we are what we eat and if we put low grade nutritional supplements into our bodies, the results we get from our supplementation will not be as good as if we use higher quality supplements.

Most of your higher quality nutritional supplements are more assimilable by the body so there is less wasted that passes through the body and out into the sewer system.  You may even want to look into powders you can add to juice or liquid nutritional supplements as they have the highest degree of assimilability of any and in the end, that is what you want.