Eight months old baby if not yet teething, belong to the dental development delay, this situation may have the following several reasons: a, by genetic factors, such as parents also belong to the case of developmental delay, this baby is also prone to developmental delay phenomenon, this situation is normal parents do not need to worry about. Second, the baby’s calcium deficiency caused by delayed dental development, because parents do not give the baby calcium supplements, or in the supplemental food, diet containing calcium food to eat less, milk contains less calcium, and at the same time not given the correct vitamin D supplement, will lead to the baby calcium deficiency. Calcium deficiency can lead to backward dental development, so you need to give your baby calcium supplements, commonly used are calcium gluconate oral solution, and also pay attention to vitamin D supplementation, vitamin D only in a sufficient state is conducive to the absorption of calcium, otherwise calcium is not absorbed, so it is good to give vitamin D supplementation at the same time.