#AskTheExpert My child is 2.5 months old and he is on breast milk and formula milk . He vomit a lot at a certain time period at around 12 noon when some formula milk is given to him . Also he is not having breast milk for the past 2 days from my left breast and he cries when i try from left breast . I also observed a thing that when we give vitamin d to him he sleeps a lot after it .