Teeth can fall out earlier or later. These little teeth need to be healthy for 6-12 years until the permanent teeth are in. This seems to be mostly a matter of opinion. Prolonged use of either of these, could possibly alter the teeth growth. Some say one is better than the other, but the parent and the child are the only only ones who can decide what is best for that child.
Calcium is of course very important in the development and maintenance of teeth.
Vitamin D helps the teeth use the calcium efficiently. Vitamin A is needed for normal enamel formation. If your baby receives a bedtime bottle, or falls asleep while nursing, now may be a good time to break that habit. Lactose can play a big part in tooth decay. The saliva that normally helps to wash the mouth, decreases during sleep, leaving the sugars to do their dirty work on those little teeth.