All eyes are on the probe of the recent health scandal in Japan, as the number of people hospitalized after taking Kobayashi Pharmaceutical's red yeast rice dietary supplements has kept increasing over the past two weeks.

As of April 4, five people died and 196 people were hospitalized after taking the supplements in question, according to Japan's Ministry of Health, Labor and Welfare.

Kobayashi Pharmaceutical said some people had experienced symptoms that often show up in kidney diseases after taking the supplements. Now, the use of red yeast rice raw materials produced by the company has led to increased recalls of products by other companies.

A buyer-beware situation

Like many products made in Japan, those of Kobayashi Pharmaceutical had been popular with Chinese consumers. Its sales in the Chinese mainland have been increasing in recent years, with net sales standing at 10.5 billion yen (about $69 million) in 2023, according to data from Kobayashi Pharmaceutical.

Its financial reports also show that the United States and Chinese mainland are two major markets for the company's international business, accounting for over 65 percent of its total international sales in 2023.

Consumers should be skeptical when a claim on a label sounds too good to be true when buying supplements, Amy Cadwallader, director for regulatory and public policy development at US Pharmacopeia (USP), told CBS News while analyzing the scandal. USP is an independent scientific nonprofit focused on safety standards for drugs, supplements and foods.

Due to the scandal, the China Consumers Association warned Chinese consumers to stop taking Japanese supplements containing red yeast rice. The association confirmed the products were not imported for local sales in China, but purchases were possible via cross-border platforms and overseas stores.

On China's social media platform Weibo, some netizens commented that they had bought the company's products before but would not dare buy them again, although these products had not reported any problems.

The growing scandal has caused significant public concern about the safety of such products among Japanese people. "I'm worried because it's a company I trusted," a resident told China Media Group (CMG). "I hope we can find out what's going on soon."

The toxic compound

Health authorities in Japan think the people were sickened by puberulic acid, a natural toxic compound derived from blue mold, but they still lack a full picture of how this happened.

Nikkei Asia reported that the supplements linked to five deaths in Japan may have been contaminated by mold from outside the factory during production. Experts in Japan said that the blue mold may come from the air or the rice used.

"It is reported that the batch of products in question also used a variety of additives during the tableting process. Kobayashi Pharmaceutical has yet to clarify whether these additives will cause adverse reactions, at least until now," Shentu Yinhong, an expert at the China Association of Traditional Chinese Medicine, told Xinhua.

Shentu added that a Japanese company's individual quality problem does not mean that the safety of other red yeast rice products is in question.

The company's factory in Osaka makes the ingredients for the product, called beni koji in Japan, by fermenting rice using a type of mold called Monascus.

It is hard to imagine that Monascus would produce harmful substances under normal circumstances, and there is no need to worry about the safety of normal Monascus, said Hideaki Taraki, an honorary professor at the University of Tokyo who has been engaged in food-safety-related work for many years.

Poor response

Kobayashi Pharmaceutical received the first report of health problems in mid-January but didn't notify the government until March 22. It has faced criticism for its delay in warning the public.

"Disclosing the product's problem could have negative economic consequences for Kobayashi Pharmaceutical. I think this may be the reason why it did not disclose it immediately," Eiji Kusumi, a Japanese internal medicine specialist, told CMG.

"This incident has a huge impact on the health food industry," said Kusumi, adding that restoring public trust will take a long time.

Hidetoshi Tashiro, chief economist at Japan's Sigma Capital Ltd., told Xinhua that Kobayashi Pharmaceutical's food safety crisis also revealed organizational problems within the company.

Tashiro said the drug maker, as a typical Japanese family-owned enterprise, might prioritize family interests over customer interests in decision-making.

Regulation loophole

However, the crisis has reignited debate on Japan's current functional food labeling system, a lenient regulatory mechanism that may lead to negligence in safety inspections by various parties involved.

Health supplements are commonly called "functional foods" in Japan. Since 2015, manufacturers of such foods only need to submit scientific evidence supporting their claimed functionality to the consumer watchdog for registration before marketing, without the need to get approval from Japanese government agencies.

In a recent article, Japanese news agency Kyodo News said that the system has been criticized for years over the lack of sufficient scientific proof of safety and efficacy. Following reports on the scandal, the Japanese Consumer Affairs Agency announced plans to conduct an emergency inspection of over 6,000 functional foods.

"Strict safety management by enterprises is the premise of this system. The problem this time actually hurts the people's trust in the whole system," Atsushi Osanai, a professor at Waseda University, told CMG in an interview.

"Problems know no borders. The company must see the impacts overseas aside from in Japan," said Osanai.

(With input from agencies)