1. Why do three-month-old babies need calcium supplements? Three-month-old babies are in a critical period of growth and development. At this time, the formation of bones and teeth requires a large amount of calcium. Lack of calcium can easily lead to problems such as osteoporosis and rickets. Therefore, three-month-old babies need appropriate calcium supplements. How to supplement calcium for babies in two or three months? 1. Breastfeeding: Breast milk is the best source of nutrition and is rich in calcium. therefore