Kobayashi Pharmaceutical Co. said Friday that it has confirmed a fifth death possibly linked to its red yeast rice dietary supplements, but has yet to determine the substance that may be responsible for causing health problems amid hundreds of reports of people falling ill.

The five people who have died include those in their 70s to 90s, according to the company, which has recalled its "beni-koji choleste help" supplements.

"We apologize for causing a social problem," Kobayashi Pharmaceutical President Akihiro Kobayashi said at a press conference in Osaka.

Kobayashi said the substance in question "could have been derived from mold, but we have yet to ascertain which (chemical) structure it has."

A senior official of the company said some 680 people have received or wish to receive outpatient treatment for symptoms suspected to be linked to the supplement so far, and the company will compensate them along with 114 people who have been hospitalized.

The drugmaker announced on March 22 that people who took the supplements, meant to help lower levels of LDL cholesterol, known as "bad" cholesterol, were experiencing symptoms such as kidney disease.

Among other notable reported symptoms were swelling and fatigue.

The company initially suspected the involvement of citrinin, a toxic metabolite produced by red yeast rice, but said earlier it has not been detected in its products.

==Kyodo

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