Americans take fewer multivitamins but more vitamin D, omega-3s

Story highlights

  • About 52% of Americans take dietary supplements
  • Research over the past decade has showed that many don't help health

(CNN)The majority of American adults use dietary supplements. That number has remained steady for about the past decade, according to a new study, despite an increase in the number of studies that show that many supplements, with some exceptions, produce mixed results at best or, at worst, have no real health benefits at all.

The study appears in the latest edition of the Journal of the American Medical Association.
    Americans spent about $34.9 billion on supplements in 2013 alone, according to National Institutes of Health research. There were an estimated 50,000 supplement products to choose from in the 2012 market.