How much is spent annually on "natural" supplements in the U.S.?

“One in every three Americans are now choosing natural healthcare over Western medicine as a primary form of treatment. Natural medicine is a billion dollar industry promising you everything from curing migraines to putting diseases like fibromyalgia and arthritis into remission.”

Source: http://www.realnaturalmedicine.com/mistakes.htm

“Americans spend in excess of $20 billion annually on herbal and dietary supplements, most often without the guidance of a health care practitioner.”

http://www.scripps.org/events/natural-supplements-an-evidence-based-update