According to the U.S. Better Business Bureau (BBB), consumer complaints about dietary supplement companies were up 360% in 2009. More than 3,500 consumer complaints were filed regarding “vitamins and food supplements” in 2009, compared to just 766 in 2008.

Supplements rank as the 55th most-complained about product category, out of approximately 3,900 categories tracked by the U.S. BBB. In 2008, supplements ranked as the 198th most-complained about category.

The rise in complaints is primarily due to a handful of online marketers who sell acai supplements, according to U.S. BBB Spokesperson Alison Southwick.

The majority of complaints about the acai marketers have centered on consumers being billed incorrectly. Perhaps even more alarming, more than 10,000 complaints were reported for the “herbs” category—up 404% over 2008 totals—making it the 14th most-complained about product category.

The “vitamins and food supplements” and “herbs” combined categories saw complaints spike by 393% with nearly 14,000 complaints filed in 2009. Read more from Nutrition Business Journal.