Photo: screenshot from Hunan Economic TV.

China market regulation authorities had urged Hunan Province on Wednesday to investigate the case in which a local maternal and child store sold a protein solid drink as milk formula which caused several children to develop 'big-head' disease and rickets after consuming the product.

Local authorities said no hospitals or doctors have been found to be involved in the case, reported The Beijing News on Wednesday. 

Five parents in Yongxing county, Chenzhou, recently found their children to be suffering from eczema, severe weight loss, a skull deformity resembling "big head" and a number of other unusual diseases, the Hunan Economic TV reported on Monday. 

The children had all used a "special medical milk powder" purchased at a local maternal and child store after being diagnosed as milk allergic and doctors recommended that they use amino acid milk powder, according to the reports.

The salesperson who sold the "milk powder" to the parents at the shop claimed that the product is the best-selling "milk powder" for children with the allergy, said one parent in the TV report.

When asked why the product reads "solid drink" on the packaging, the salesperson said it was just "another name for milk," according to the parent. 

A 400 gram can of the special medical "milk powder" sells for 298 yuan ($42). "Although the product cost more than twice as much as the ordinary ones, I still kept buying it for my kid," another parent, surnamed Zhu, told the media.

Zhu noted that her daughter had consumed 89 cans of the "milk powder" in two years, during which time she often had a cough, eczema, and patted her own head.

The 3-year-old girl weighs less than 15 kilograms and her hair has turned yellowish. She was later diagnosed with rickets and lacking vitamins A and B.

Zhu thinks the store should be held responsible and pay compensation for her daughter's disease as salespersons misled customers to buy the solid drink thinking it was milk powder.

But an owner of the store claimed that it was the manufacturer who promoted the product as a nutritional supplement for kids with allergies, reported The Beijing News.

The manufacturer of the product told media that the company had stopped its production in mid-2019 and the solid drink meets national standards and is suitable for all kinds of people, reported The Beijing News. 

The company also said it is not clear why the product was sold at maternal and child stores to children with milk allergies.

All of the 47 solid drinks procured by the stores in question have been sold to customers. 

Local county government said the hospitals would provide free full physical examinations for children who have used the products. Those who fell sick will be treated under guidance from nutrition experts.

The China State Administration for Marketing Regulation released a notification on Wednesday, urging authorities in Hunan Province to conduct a thorough investigation into the illegal act of selling ordinary food as special medical formula food. 

According to China's food safety law, special medical formula food should go through strict registration management and ex-factory batch inspection to ensure its quality and safety.

The news sparked a wave of criticism on social media and drew strong emotions among Chinese netizens who recalled the Sanlu infant milk scandal in 2008, which took the lives of six infants and sickened some 300,000 babies. 

Netizens called for a thorough investigation into the case and tougher management over the formula industry. 

The case was not isolated to Chenzhou. 

In March 30, a joint letter was released by several parents in Chenzhou whose kids developed "big-head" disease after using another special medical "milk powder" that doctors had recommended for children allergic to milk. 

The doctor in question was later found to have been working with a maternal and child store to promote the product to the patients, which actually is also a solid drink. 

After using the "milk" as the only food source for a long time, the children suffered malnutrition, viscera injury of different degrees and a developmental delay in height, intelligence and mobility.