Vitamin D is one of the fat-soluble vitamins, which is made by the body when the skin is exposed to sunlight, and it is a very important nutrient for infants and newborns who are going through a phase of accelerated growth at that time. One of the benefits of vitamin D for infants is that it promotes healthy bones and teeth by regulating calcium levels. In the blood, it also supports the heart, brain, and other organs, and prevents deficiency.