Which two nutrients are breast milk notably lower in?

Breast milk is known to be notably lower in fluoride and iron compared to other nutrients. This is significant because while breast milk provides all the essential nutrients that an infant needs during the initial months of life, the levels of iron are not sufficient to meet the needs of a growing baby after about six months. As a result, pediatricians often recommend introducing iron-rich foods into an infant's diet as they transition to solid foods.

Fluoride, while important for dental health, is also present in low amounts in breast milk, which is why some healthcare providers may recommend fluoride supplementation after the first year of life, especially if the water supply lacks adequate fluoride levels.

Other nutrient combinations listed either do not accurately reflect breast milk's composition or do not highlight its notably lower levels effectively. For example, breast milk does contain sufficient calcium for an infant's early needs, and while some protein is present, it is perfectly balanced for an infant's development.