Two deaths were linked Wednesday to a growing health scare in Japan around dietary supplements meant to lower cholesterol, with more than 100 people reportedly hospitalized.

The drugmaker at the center of the concerns, Kobayashi Pharmaceutical, told AFP that it was aware of two deaths possibly related to its prescription-free tablets.

It has recalled three supplement brands STR / JIJI Press / AFP "beni koji choleste help" and two other products STR / JIJI Press / AFP which contain an ingredient called red yeast rice, or "beni koji".

Medical research describes red yeast rice as an alternative to statins for lowering high cholesterol but also warns of a risk of organ damage depending on its chemical make-up.

Kobayashi Pharmaceutical said Tuesday it was aware of 75 hospitalizations in total in relation to its products, which it recalled after kidney complaints from customers.

Several Japanese media reports said that this number has now risen to 106, but neither the drugmaker or the health ministry were immediately able to confirm the latest figure.

The company has cautioned that it has not reached a conclusion on a causal link between the health problems and its supplements, which it voluntarily recalled on Friday.

It has also supplied red yeast rice to around 50 other firms in Japan and two in Taiwan, said the Osaka-based company, which sells over-the-counter drugs and supplements.

Dozens of Japanese firms that used the beni koji provided by Kobayashi Pharmaceutical in their products have also separately announced recalls.

These include a rose-coloured sparkling sake, salad dressing, bread, and "miso" bean paste used in many traditional dishes, along with various health tablets.

'Need for a response'

Health Minister Keizo Takemi said on Tuesday that the government had told Kobayashi Pharmaceutical to "promptly provide information" on the situation.

The health ministry has also "instructed local authorities nationwide to collect information on health damage", he said, offering condolences to those affected.

Authorities will consult with the company, and a government meeting will be held this week "to discuss the status of the case and the need for a response", Takemi added.

In Wednesday trading Kobayashi Pharmaceutical's share price dropped four percent.

The previous day, the drugmaker had said that the first person reported dead had regularly purchased one of the recalled products over the course of nearly three years.

"We're now aware of one instance where there is a potential causal link between a death and our product," the company said in a statement.

"We are currently investigating the link, and what happened," it added, offering "deepest apologies".

Analysis has found a possibility that the products contained "ingredients we had not intended to include", the company has said.

But its analysis did not find any citrinin produced by red yeast rice, which is toxic and can damage the kidneys.

Red yeast rice is "made by fermenting steamed rice with food fungus, and is often used to lower high cholesterol as an alternative to statin medication", according to a 2019 paper in the British Medical Journal.

Concerns have been raised in the past over red yeast rice products that contain high levels of a compound called monacolin K, which has the same structure as medically approved cholesterol drugs.

"Red yeast rice products that contain significant amounts of monacolin K can have the same potential side effects as statin drugs, including muscle, kidney, and liver damage," the US National Center for Complementary and Integrative Health says on its website.