A sprawling health scandal involving Kobayashi Pharmaceutical’s dietary supplements has caused a public scare around beni kōji (rice fermented with red yeast), with some worried consumers rushing to inquire about the safety of the food ingredient used by businesses with no links to the Osaka-based drugmaker.

Kobayashi Pharmaceutical has so far reported the deaths of five people and over 110 hospitalizations linked to its dietary supplements containing beni kо̄ji. The firm has said a chemical compound naturally made by blue mold may have been mixed in during the production process of beni kо̄ji at one of its factories.

The scandal, however, has spread to makers and marketers of beni kо̄ji unrelated to the firm. The red yeast rice has been widely used in Japan and elsewhere as a food additive, and features prominently in Okinawan cuisine, particularly in a dish called tōfuyō.

Tо̄fuyо̄, which is believed to have originated in Ming dynasty China, is made by fermenting and aging Okinawan tofu with kо̄ji (malted rice), beni kо̄ji and awamori (a type of Okinawan distilled liquor).

At Okinawa Products Associated, which runs the Washita Shop Okinawan food chain with 10 locations across the country, an official expressed concern that public fears will lead to consumers avoiding its products, particularly tōfuyō.

“If there were any major issues with beni kо̄ji itself, it would be regrettable as we’ve been selling tо̄fuyо̄ products for a long time,” said Takako Akamine, the company’s head of product development. “We just hope that negative rumors don’t spread widely.”

The company’s customer center in Tokyo has received more than 50 calls in the space of a week from customers inquiring about its beni kо̄ji products, Akamine said. It continues to sell its products as usual, having confirmed that they do not contain raw materials sourced from Kobayashi Pharmaceutical.

Numerous manufacturers that use beni kо̄ji in their products — ranging from pet food to salted fish and rice crackers — have issued statements on their websites saying they have no links to red yeast rice made by Kobayashi Pharmaceutical.

Ezaki Glico, an Osaka-based manufacturer of confections and dairy products, said that from Monday through Wednesday last week it had received dozens of calls per day from customers asking about the firm’s use of beni kо̄ji. It declined to say exactly how many inquiries it had received after Kobayashi Pharmaceutical's first news conference on March 22.

In that news conference, the drugmaker said there had been reports of kidney problems among users of its dietary supplements. It announced a voluntary recall of three types of its supplements touting health-enhancing effects.

Last Tuesday, Glico released a statement saying that its products do not use Kobayashi Pharmaceutical’s red yeast rice. Since then, the inquiries have somewhat subsided, said Takeru Goto, a spokesperson for the company.

Glico uses beni kо̄ji as a coloring ingredient in several of its products, including the strawberry milk drink Mairudo Ichigo Ore and its strawberry-flavored Cream Collon biscuit rolls. The customers had called in after seeing beni kо̄ji on the list of ingredients on the product packaging, Goto said.

“We have been telling the customers that our beni kо̄ji has been manufactured in ways that meet nationally set safety standards and has no links to Kobayashi Pharmaceutical,” he said.