Calcium enters the body through the gastro-intestinal tract, is absorbed mainly in the upper small intestine and is excreted via the bowel, kidneys and skin.
There are two types of calcium. One type of calcium is tightly bound within the bone and the other more accessible type of calcium is found on the bone.
The skeleton serves as a bank of minerals for the body. 99% of the calcium in human body is stored in bones and teeth which support body structure.
Combines with phosphorus to form bones and teeth, making them hard and resistant to breaks and decay. High dietary calcium intake is necessary for infants, children and adolescents to get enough calcium for their bones and teeth to develop normally. Getting enough calcium early in life helps bones remain strong later in life.
During skeletal growth and maturation, i.e. until the age of the early twenties in humans, calcium accumulates in the skeleton at an average rate of 150 mg a day.
Without this calcium, bones will become weak. As they weaken, fractures and breakage can occur i.e., osteoporosis, in which the bones become porous and fragile because calcium is withdrawn from the bones and other areas faster than it is deposited in them.
Calcium in human bones
