Fat soluble vitamins, once they have been stored in tissues in the body, tend to remain there. This means that if a person takes in too much of a fat soluble vitamin, over time they can have too much of that vitamin present in their body, a potentially dangerous condition called hypervitaminosis (literally, too much vitamin in the body).
If your blood lacks the Rh antigen, it is called Rh-negative. If it has the antigen, it is called Rh-positive. When the mother is Rh-negative and the father is Rh-positive, the fetus can inherit the Rh factor from the father. This makes the fetus Rh-positive too.
Rh is a substance that most people have in their blood (Rh positive) but some people don't (Rh negative). A person who is Rh negative can be exposed to Rh positive blood through a mismatched blood transfusion or during pregnancy when the baby has the opposite blood type. When this exposure happens, the Rh negative blood will respond by making antibodies that will try to destroy the Rh positive blood cells.