The estimated risk of enamel fluorosis in infants fed reconstituted infant formula correlates with which factor?

• A. Vitamin D intake
• B. Fluoride concentration in the drinking water
• C. Iron intake
• D. Protein intake

Answer: (B)

Fluorosis risk is driven by fluoride exposure during enamel formation. In infants fed reconstituted formula, most fluoride comes from the water used to dilute the powder. The higher the fluoride concentration in that drinking water, the more fluoride the infant ingests daily, increasing the risk of enamel fluorosis during the critical years of enamel development. Vitamin D, iron, or protein intake don’t directly determine fluoride exposure in this context, so they don’t predict fluorosis risk from reconstituted formula.