Four-month-old baby can eat milk calcium, calcium has an important role in the growth and development of four-month-old baby, mainly to promote bone growth and maintain neuromuscular excitability. four-month-old baby with occipital baldness or nocturnal fussiness, should go to a regular hospital pediatrician, and blood calcium testing, if there is a decrease in blood calcium, should be actively supplemented with calcium elements, by eating milk calcium or capsule-type vitamin D3. once the blood calcium is not low, not should let the baby eat milk calcium, normal milk can meet the baby’s growth and development, if the need for calcium elements, additional excessive supplementation, so that the baby’s serum calcium level is too high, increasing the burden of kidney metabolism, causing organic lesions. In short, four months of the baby can eat milk calcium, should be clear whether the baby lack of calcium, daily life can be more sunshine, pay attention to sunburn baby’s delicate skin.