What supplement is required for infants who are fed with ready-to-use formula?

The correct choice for this question is related to the nutritional needs of infants who are fed with ready-to-use (commercial) infant formula. Typically, ready-to-use formulas are designed to be nutritionally complete for infants, but they may lack certain essential nutrients that are necessary for adequate growth and development.

In particular, fluoride is often not added to infant formulas because excessive fluoride can lead to dental problems such as dental fluorosis. However, for infants who are fed with ready-to-use formulas and do not receive any fluoride from other sources (like fluoridated drinking water), supplementation may be considered to help prevent future dental issues as the child grows.

While vitamin C, iron, and vitamin D are also important for infant health, the specific supplementation needed can depend on various factors such as the infant's age, health status, and dietary intake. For example, infants typically need iron starting around 4-6 months of age, and vitamin D is important for bone health and is recommended for breastfeeding infants as they might not get enough from breast milk alone. Therefore, for ready-to-use formula-fed infants, fluoride stands out in this context, as it addresses the potential gap in their diet regarding dental health, given that fluoride is not found in adequate amounts in many