The serving size is dependent on the age of the infant according to FDA regulations. For infants 12 months and older, the 0.5 g serving size is suggested twice daily (total of 10 billion CFUs, or 1 g).
For infants under 6-12 months of age, the 0.5 g serving is once daily (total of 5 billion CFUs).
Note that the FDA does not recognize under 6 months old as an age group for nutritional RDI standards. A infant is defined as 6-12 months. For infants under 6 months old, please talk to your doctor before considering the use of this product for your child.