Babies should start obtaining zinc from complementary foods when they begin introducing solids at around four months old. It’s important not to over-supplement trace elements, as excessive intake can negatively impact health. Generally, if a child spends less time in the sun or is formula-fed, it’s recommended to start supplementing calcium from one month old, continuing until the child is 2 to 3 years old. Before three months, babies typically get calcium from cod liver oil, while mothers supplement with calcium. It’s suggested to give infants Icoshin and mothers Calcis D. After three months, babies can also appropriately supplement with calcium and cod liver oil, but be cautious not to exceed recommended amounts. Zinc supplements can be started after the baby is six months old.