What Does "MADE IN THE USA" Mean for Supplements?

I recently got an email from a customer asking this specific question regarding one of our products, Nutribiotics Defense Plus.  While this email was specific to one company, it goes to the heart of how we choose our brands.  Here's my answer...

Good question!  I didn’t know the exact answer so I call the manufacturer.  I know that they have been the leaders in grapefruit seed extract (GSE; the primary ingredient in Defense Plus) for 30 years and we have a huge repeat business for their products, especially Defense Plus.  Margaret recommends Defense Plus regularly during cold and flu season.  

Anyway, based on my conversation with the manufacturer, Nutribiotics is located in California and has multiple US-based manufacturing plants depending on the product.  They source their ingredients based on best quality available and have it verified by a third party lab (as do all good supplements manufacturers).  For GSE, it is sourced from US sources.  Other ingredients are sourced from best available and may not be US.  She said that they try to source from US first but quality is always their first priority.  I asked her about their key to success and she said that it was keeping the products clean of allergens for sensitive people (I didn’t know that).
In general, we like buying from American manufacturers but the ingredients come from around the world.  The best companies source the highest quality raw materials and have them third party tested…which means a higher price.  The trick is the buy the best products at the best prices.  We always have Defense Plus on sale!  And we give good service as in this email!
We buy from American companies who are committed to quality and testing of their products.  However, that means that some/many of their ingredients will come from sources outside the US because that's where the best ingredients are found/produced.  We know or at least know the story of the founders/owners of these companies and personal connection is the beginning of our trust in their brands.  The rest comes from the use of their products in our family and our customers' families.