These results were revealed after the authorities tested 14 brands of infant formula in the market.
CFS assistant director Miranda Lee Siu-yuen said the government will introduce nutritional labeling for baby food as soon as possible.
Insufficient iodine levels can hinder the development of babies. The recommended minimum and maximum iodine levels in infant formulas are 10 microgram/100 kilocalorie and 60 microgram/100 kilocalorie.