Giving the government's first detailed account of a scandal that erupted last week over milk powder contaminated with a chemical used to make plastics, Chen said 6,244 babies had fallen ill after consuming the product.
While many of those had recovered, 1,327 remained in hospital and 158 of those were suffering from acute kidney failure, Chen told reporters.
Three babies had died, he said, updating the previous toll by one.
The head of China's quality watchdog body, Li Changjiang, told the press conference that 22 companies nationwide were found to have produced the milk powder that contained melamine.
Melamine is normally used for making plastics and glues, but authorities have said it was put into the milk powders to make it appear the product had more protein.
The industrial chemical is being blamed for causing kidney stones in the affected babies, a condition that is rare in infants but which causes a range of health risks.
Babies have reportedly been taken to hospital unable to pass urine and suffering severe vomiting.
The scandal is the latest to rock China's food industry, which has been tarnished by a series of health scares over dangerous products, some of which have been exported.