The human body needs calcium more than any other mineral. A man weighing 70 kilo gram contains 1 kilogram of calcium. About 99% of the quantity in the body is used for building strong bones and teeth and the remaining 1% is used by the blood, muscles and nerves.
Calcium performs many important functions. Without this mineral, the contractions of the heart would be faulty, the muscles would not contract properly to make the limbs move and blood would not cloth. Calcium stimulates enzymes in the digestive process and coordinates the functions of all the other minerals in the body.
Calcium is found in milk and milk products, whole wheat, leafy vegetables such as lettuce, spinach, and cabbage; carrots, watercress, oranges and lemons, almonds and walnuts. A daily intake of about 0.4 to 0.6 grams of calcium is considered desirable for an adult. The requirement is larger for growing children, pregnant and lactating women. Deficiency may cause porous and fragile bones, tooth decay, heart palpitations, muscle crams, insomnia and irritability.
A large increase in the dietary supply of calcium is needed in tetany and when the bones are decalcified due to poor calcium absorption as rickets, osteomalacia and the malabsorption syndrome. Liberal quantity of calcium is also necessary when excessive calcium has been lost from the body, as an hyperparathyroidism or chronic renal disease.