 [ Symptoms ] i am feeling discomfort in chest i did ecg and chest x ray all normal [ Disease ] that depends on their diet most kids need supplemental vitamin d because it not found naturally in many foods and the sun is not reliable the american academy of pediatrics recommends supplementing with d for children not receiving enough through diet it would take 6 cups of milk to get the 600iu recommended    and that would be too much milk for kids anyway as for omega 3 fatty acids i assume your referring to dha which is important for health and brain development in babies and young toddlers if a toddler eats fish about twice a week small portions than it is not needed if he does not eat any fish you may want to consider supplementing fortified foods have some but not as much as in fish